This file is primarily concerned with drilling procedures and tips for making holes in metal. Related operations may crop up in the conversations. Before beginning this web site, I was already gathering information on subjects like "Drilling Tips" and "Boring" and "Reaming" and "Lapping". They once had separate files on my computer, and originally had their own separate files here. It has become painfully obvious that while lapping is a very useful process, you folks rarely talk about it. And when you do talk about it, you often throw some lapping info into a thread that started as boring or reaming, etc. Consequently the messages from the separate "Lapping" and "Reaming" files have been combined into the "Lapping and Reaming" file. There is still some other lapping and/or reaming info mixed in with the Boring or Drilling Tips messages. Consequently, you should really read the last three files to find good solutions that may involve multiple processes. The "Finish and Polish" file may also be useful for your particular need, as lapping is related to some polishing techniques. Let's just clarify a few terms so that we are all on track here. These are my very simple definitions. "Drilling" most commonly is the act of using a drill bit to make a "round" hole of a specific diameter. The resulting hole is often rough, and rarely of the same diameter as the drill bit, and often not even round, and can end up quite crooked in direction from the path intended. "Boring" is the act of using a boring tool to widen an existing (drilled) hole to a larger diameter. By slowly increasing the diameter of the boring tool's cutting arc in several stages (so as not to bend the tool sideways), the resultant hole is round, and straight (even if the original drill bit had wandered), and fairly smooth. "Reaming" is the act of passing a precision reaming cutter through an existing hole; the reamer is only a small amount larger in diameter than the existing hole. The reamer brings the hole to a perfectly round shape and size appropriate to the size of the reamer. The walls of the reamed hole will be smoother than a drilled or bored hole. If the original hole was straight, the reamed hole will be too. But a reamer will follow a crooked hole if that is what you started with. "Lapping" (a hole's wall) is the act of passing a lap repeatedly through the hole until the wall is smooth and free from minor defects or tool marks. The lap, usually a metal cylinder, is the perfect matching shape for the inside of the hole and is just smaller enough in diameter to allow for a lapping compound's particles to fit between the lap and the wall. The lap itself must be softer than the hole's wall material so that particles of the lapping compound might bed into the lap, but not into the wall. Depending on the smoothness required, lapping may be done with successively finer grit lapping compounds until the desired result is achieved. Lapping, properly done, does not significantly increase the diameter of the hole. Where the hole is now a very slight "interference fit" (an object to be inserted needs force or heating-of-the-hole-part/ cooling-of-the-insert-part), lapping may change that to a precision sliding fit. Bigger hole-size changes are best done with a reamer or careful boring operation first. If you got to this file directly from my HOME PAGE, return there by using your browser's back button. BUT if you came to this file as the result of a web search engine, see more than 70 additional files on my home page Machining and Metalworking at Home http://www.janellestudio.com/metal/ SAFETY WARNING BEWARE: DO NOT ASSUME that any subject matter or procedure or process is safe or correct or appropriate just because it was mentioned in a news/user group or was included in these files or on this site or on any other web site or was published in a magazine or book or video. Working with metals and machinery and chemicals and electrical equipment is inherently dangerous. Wear safety devices and clothing as appropriate. Remove watches, rings, and jewellery -- and secure or remove loose clothing -- before operating any machine. Read, understand and follow the latest operating procedures and safety instructions provided by the manufacturer of your machine or tool or product. If you do not have those most recent official instructions, acquire a copy through the manufacturer before operating or using their product. Where the company no longer exists, use the appropriate news or user group to locate an official copy. Be careful -- original instructions may not meet current safety standards. Updated safety information and operating instructions may also be available through a local club, a local professional in the trade, a local business, or an appropriate government agency. In every case, use your common sense before beginning or taking the next step; and do not proceed if you have any questions or doubts about any procedure, or the safety of any procedure. Follow all laws and codes, and employ certified or licenced professionals as required by those laws or codes. Hazardous tasks beyond your competence or expertise should also be contracted to professionals. Let's be really careful out there. (c) Copyright 2003 - 2008 Machining and Metalworking at Home The form of the collected work in this text file (including editing, additions, and notes) is copyrighted and this file is not to be reproduced by any means, including electronic, without written permission except for strictly personal use. ========================================================================= Date: Wed, 10 Jan 2001 17:10:35 -0000 From: "Jack Gartner" Subject: Problem drilling into cast iron I've a problem that I hope someone can help me with and/or explain. I'm trying to drill some small (#72 drill) holes in a piece of cast iron. Drilled two holes without problem, then on the third the drill bit just wouldn't work. Replaced the bit with a new sharp one, and same problem. I took a look at the part and found that where I was trying to drill, the cast iron was very shiny as if it was a different kind of metal. The majority of the part is gray except for the corner where it is a shiny silver color and seems very hard. Can anyone tell me what's going on? Can this be annealed so I can drill it? Thanks, Jack -------------------- Date: Wed, 10 Jan 2001 13:49:44 -0500 From: "Rich D." Subject: Re: Problem drilling into cast iron Jack, What you have is a casting with chilled spots (white iron). These happen when the casting is allowed to cool too quickly or just plain poor quality. White iron is extremely hard, almost like carbide tools. If you can find a carbide drill in that size, you might succeed in finishing the hole. Annealing requires heating for many hours in an oven to some high temp. I am not familiar with the details. Rich D. ------------------ Date: Mon, 22 Jan 2001 17:22:13 -0500 From: "Paul & Charlene Wilson" Subject: Re: QC Tool Post ?? I had an honest to goodness machinist show me this trick for finding the center of a piece in the lathe, and just last night it dawned on me to use the same trick to find the top of a round piece - for example, drilling a hole in a shaft for a set screw. I just laid my 6" scale on the shaft in the vise, ran the drill down till the bit pinned the scale, and moved it back and forth until the scale was horizontal. Afterwards, I wondered why I had struggled so long with this job - I'm getting slower as I get older, I guess. On the other hand, I am getting more stuff in my bag of tricks ... Paul ---------------------- Date: Fri, 02 Mar 2001 09:59:29 -0500 From: ron ginger Subject: Screw machine drills It was mentioned here a while back that screw machine size drills are very handy. They are only about half the length of normal drills, and in Sherline size machines often make it opossible to get in over work and drill where a regular drill wont fit. They are much stiffer, so often you can start a hole without a center drill. And they save a lot of cranking up and down on the Z axis. I just got the March 2001 sale flyer from MSC, and they have 2 ads for them. On page 13 there are both fractional set, split point sets and number size set, starting at $41.70 On page 9 there are more, a different brand, with several sets and styles. You don't often see these sets on sale. ron ginger ------------------------------ Date: Tue, 06 Mar 2001 05:07:45 -0000 From: ballendox~xxyahoo.com Subject: Re: How much money to spend on a drill set? John, DON'T try to "save money" here! If you're using sherline equipment, I'd suggest as FULL a set as you can afford of "split-point" stub- length drills in HSS at least 1/16 to 1/2 ,by 64ths. Split point bits are hard to re-sharpen (without expertise, or a good *darex, shameless plug for a good tool company, but NOT their "drill doctor" line!!!* drill sharpener, but they are SOOOO nice to use; and the stub length just makes 'em better. I did buy one of the cheap 115 pc. sets, and it is being filled bit by bit(pun intended) with GOOD drill bits. I'm not saying this was/is a bad thing. The 115's ARE a quick/cheap way to have ALL the sizes AVAILABLE, even though you will replace/hand grind those you use often, out of need or frustration with the poor cutting (which is okay for a once-in-awhile" cut, but not for general metal use, IMO. Hope this helps. Ballendo P.S. It can be worthwhile to have a separate set for aluminum, and you will find that the "black bits" are designed for ferrous metals, and the "shiny bits" are for aluminum (again, talking the cheap bit sets) P.P.S. I've heard other swear by the cobalt bits, but I haven't used them (in the cheap sets, that is; Good cobalt bits are as nice as they are expensive) P.P.P.S. Recently I saw a suggestion of dipping bits used in aluminum in lye to clean. It makes sense, since Lye(sodium Hydroxide: DRANO) is used to "etch" aluminum prior to painting; but I have n't tested the idea yet. ---------------------- Date: Thu, 08 Mar 2001 17:57:32 -0500 From: ron ginger Subject: Re: Re: How much money to spend on a drill set? jbeansx~xxpacbell.net wrote: > Thanks. Do you use one of those sharpening machines to sharpen your > bits? Any affordable suggestions? This can be a long topic. There are old-timers that claim they can do a fine job by hand. I think they are a bit optimistic, or not really fussy about the drill. I have certainly never been able to freehand a drill worth a damn. There is a drill grinding jig sold by General and was sold by Sears. This is an angle mount gadget you bolt alongside your bench grinder. It sharpens one flute at a time, and you sweep the drill through an angle to get the proper relief. These sell for about US$30 last time I looked. They work OK, but the problem is you must remove the drill and turn it over to grind the second flute. There are parts of the jig to hold it, but its hard to get exactly right, particularly on the smaller drills. A recent article in HSM showed mounting one, and the most recent article has a letter to the editor noting the first article was bad in that it removed the small angle of the mount that is what causes the relief. The Darex Company make a lot of special drill sharpeners, up to multi-thousand $$$. They sell a home shop gadget called the Drill Doctor for under $200. This tool gets a LOT of controversy on rec.crafts.metalworking. Some guys really knock it, some like it. There were a couple 'recalls' when it first came out, and a number of complaints on its plastic construction. I would say the general feeling is its just barely OK. Most of the high end machines have very fancy (expensive) collets to hold the drills, and complicated cams and beveled surfaces to cause the proper relief. There is one grinder, called the SRD Drill grinder that is a very elegant and simple machine. I lucked into a used one at NAMES one year. It has a patented chuck and sharpens on the INSIDE of a cup wheel so it gets the relief by the sweep of the wheel. A very nice gadget, but hard to find used, and about $1000 new. A friend of mine that runs a machine shop for his living, makes a very convincing argument for just throwing out dull drills and buying a new one. A few humdered $ spent on a machine to sharpen under $1 drills and spening a few minutes to do it is hard to justify. My argument is that if I screw up a dril on a Sunday afternoon I can sharpen it and keep working. (But I also like collecting neat tools and machines ;-) ron ginger -------------------------- Date: Fri, 9 Mar 2001 08:25:04 -0800 From: "Marcus & Eva" Subject: Drill grinding Hi guys: Regarding the subject of drill grinding, here's my two cents worth. We hand ground all our drills for 15 years or more in the toolroom where I worked. The hardest drills to grind are the really small ones, (less than 0.040" dia) and the really large ones. (bigger than 3/4") I've always ground split points on all my hand-ground drills. That way the radial relief is just a flat tipped at the correct angles, rather than the complex compound motion required for true helical relief. which is what the factory grinds on) Split point drills are weaker, but they cut more freely. Since the grinding motion is so much easier, its relatively simple to grind a good drill. Dress the grinding wheel nice and flat, and put a teeny radius on the right side corner. Eyeball your primary relief and grind it on. Immediately spin the drill 180 deg. and grind the second flat. Now check them both for acceptable radial relief. The point angle and consistency of relief will be easy to control because you only made one motion to grind the second flute (you spun the drill 180 deg.) Point concentricity can be adjusted now because you have a guide to work from. Once you are happy with the shape of the primary relief, you can relieve the heels of each flute with a second flat, until you are left with a skinny land. That's it! All there is to it. For big drills, chuck them up in the lathe and dress the point with a toolpost grinder. That gives you a nice reference for grinding the lips evenly. Cheers Marcus PS: Oh yeah, and like Ballendo says: practice lots!! Budget yourself 30 sec to grind a 1/4 " drill. That way you will learn not to piss around on it, and you will actually grind better drills. ---------------------------- Date: Thu, 22 Mar 2001 12:12:15 -0000 From: ballendox~xxyahoo.com Subject: re:Re: wandering drill Hello, Coupla' thoughts... Center drills must be used such that the "follow-up" drill diameter is WITHIN the cone shape made by the center drill! Otherwise, the center drill cannot do its' job! So if you are using just a "dimple" at the tip, and following it up with a 1/4 inch bit, then yes, this is incorrect procedure... The whole point (pun intended) of using a centerr drill is to have the twist drill be guided in the cut by its' OUTER diameter, NOT its point. The short length of the center drill is to eliminate deflection while drilling this initial "locating cone". Also that it has a cutting geometry designed to "try to find" the center of a spinning workpiece. Which brings us to the second point... The center drill "should" try to move to the center of the spinning stock. Of course, if you are TOO far off, it can't. So, maybe locking the lever feed and loosening the tailstock on the ways (slightly) will give better results. You can start the cut this way (even using your "muscle" to "guide" (by deflecting the tailstock with hand pressure) the center drill to the correct center as you 'slide' the tailstock on the ways to make the cone. or you could get the center dimple close enough by these means, and then tighten the tailstock, loosen the lever and finish the cut. Hope this helps. Ballendo ---------------------- Date: Mon, 23 Apr 2001 20:04:58 -0000 From: "Gavin Eyre" Subject: Finding a Center All, I am trying to drill a small hole in the center of the end of a piece of 3/16" rod using my mill. I've tried clamping the piece in a 3/16 collet in the mill and then lowering it down into the vice which is loose on the mill table. I next close the jaws and clamp the vice down to the table. When I release the collet the piece should be centered. Well in theory - in practise I'm a few thou off. I need to be as close as possible and would appreciate any help/suggestions. Unfortunately I don't own a lathe, although this may change at Wyandotte this weekend! Gavin Eyre Gavin.Eyrex~xxrsl.com ------------------------ Date: Mon, 23 Apr 2001 16:17:12 -0400 From: "Carol & Jerry Jankura" Subject: RE: Finding a Center I would try clamping the tube in the vise, and then use an edge finder to find the edge of the rod at two pieces. One other thing - how certain are you that the rod is actually round? When I've measured commercial tubing, it wasn't exactly round. This could account for some of your error. A few thousanths is not all that large an error. -- Carol & Jerry Jankura Strongsville, Ohio So many toys, so little time ----------------------------- Date: Mon, 23 Apr 2001 16:59:43 -0400 From: John Kowalchuk Subject: Re: Finding a Center At 08:04 PM 4/23/01 -0000, Gavin Eyre wrote: >I am trying to drill a small hole in the center of the end of a piece I now have a lathe so there is a different solution than I've used in the past. Think of your mill like a vertical lathe. Centre things as well as you can and mount the dril in the vise. The drill will find the centre of the spinning workpiece better than a spinning drill and fixed workpiece. John Kowalchuk maker of mutes/horns/canoes/paddles/bikes/harps Oshawa, Ontario http://home.istar.ca/~johnk Canadians don't surf the net, we paddle it. --------------------------- From: kdolanx~xxe... Date: Mon Jul 9, 2001 3:41 pm Subject: Re: Cheap Bronze (motor speed question) --- In atlas_craftsmanx~xxy..., David Jenkins wrote: > On the subject of slow speeds. I have an old Dayton Drill press, but > I feel that even at the slowest pulley configuration it turns too fast > to drill steel. Is there an electronic speed control that can be > adapted to a drill motor? Thanx Dj If you have an A/C capacitor start or capacitor run motor, probably not. FWIW, here is what I've done: Needing a new motor for an Atlas 10" I acquired, I found a 3-Phase 1HP motor and an electronic Variable Frequency converter for about $300 together from an outfit in Brooklyn NY (I think it was www.dealerselectric.com). This control takes 220V single phase and converts it to 220V 3-phase of variable frequency thus variable speed for the 3-phase motor with pretty much full torque over the full range of speed 0 to the base speed of the motor. Now you can't run two motors at the same time on this control so I put the control in a convenient place and then ran 220V power from my Dryer location to the control, then 4-wire 3-phase to behind my lathe and behind my Drill Press, with recepticles in those locations. I found a surplu 3/4HP 3-phase motor pretty cheap locally which I put on my drill press. Now when I want to use the Lathe or the Drill Press I simply unplug one and plug in the other and have variable speed for either. I havn't run across an instance where this has been inconvenient, I'm the only guy out there in the garage and I can't run both machines at the same time anyway. One of these days I'm also goung to put in some wiring to alow switching of the speed control potentiometer from one location to the other as well but so far having to take a few steps to adjust the speed hasn't been a problem. All a bit more expensive rhan I originally had planned for but it is nice to have speed control for both machines. Another option, but probably more difficult conversion-wise would be to get a surplus 90VDC motor and control and adapt it to your Drill Press. Hope this is helpful. Kirk ----------------------- From: S1 Date: Mon Jul 9, 2001 10:03 pm Subject: Re: [atlas_craftsman] Cheap Bronze You have to replace the motor with a Variable speed DC setup to reduce the speed on your drill press. As far as I know, there is no way to make a single phase AC motor variable speed. Another option, if possible is buy/ make pulleys thatwould get you the desired speed range. If you put a smaller pulley on the motor, or a larger one of the shaft belt-driven by the motor you can achieve speed reduction that way also. The way you calculate speed is simple. Motor RPM x diameter of motor pulley. Divided this answer by the diameter of the pulley being driven. You will get the RPM of the motor driven shaft. -Gabe ------------------------------ Date: Wed, 22 Aug 2001 22:42:34 EDT From: sleykinx~xxaol.com Subject: Re: Centering on a 4 jaw chuck In a message dated 08/22/2001, lnicex~xxattglobal.net writes: > I am having problems getting a bore centered when I use a drill in the tail > stock as well. I thought it was just me. I am using a #2 taper chuck > with standard length drills. Usually, I use a center drill to predrill > the center of the work before I use the chuck and drill. > Should I be using a shorter drill or what? Iceman Of course it depends on what you call "centered". If it is a good quality drill bit and properly sharpened it should start in your pilot hole and track fairly true. If it really has to be DNO then drill undersize and bore to within a thou or so and ream to final size. Caution! If it has to be a really close tollerance let it cool down before you finish it. You will end up undersized and if you slip the parts together while the freshly machined part is still hot, they will stick when it cools down. -------------------- Date: Wed, 22 Aug 2001 22:15:13 -0500 From: jmark.vanscoterx~xxamd.com Subject: RE: Centering on a 4 jaw chuck The real solution is to drill it undersize and then bore the hole with a boring bit. Drills are hardly ever right-sized or go in straight. Mark V.S. in Austin, TX ------------------ Date: Wed, 22 Aug 2001 22:42:34 EDT From: sleykinx~xxaol.com Subject: Re: Centering on a 4 jaw chuck Of course it depends on what you call "centered". If it is a good quality drill bit and properly sharpened it should start in your pilot hole and track fairly true. If it really has to be DNO then drill undersize and bore to within a thou or so and ream to final size. Caution! If it has to be a really close tollerance let it cool down before you finish it. You will end up undersized and if you slip the parts together while the freshly machined part is still hot, they will stick when it cools down. ------------------ Date: Thu, 23 Aug 2001 00:59:49 EDT From: catboat15x~xxaol.com Subject: Re: Centering on a 4 jaw chuck > You will end up undersized and if you slip the parts together while the > freshly machined part is still hot, they will stick when it cools down. And how they will stick. I made a drill pad for my tailstock with what I thought would be a press fit between the morse center with a spigot turned on and the pad with a bored hole. They would not press with the means at hand, so put the morse with the spigot in the freezer, the pad in the oven and they started on nicely, Got called away and used that partally done drill pad for years, never could get the thing assembled further on or remove it. John Meacham High Desert of California, Palmdale, Littlerock. ------------------ Date: Thu, 23 Aug 2001 09:05:25 -0400 From: Richard Parker Subject: Re: Re: center drill > > Mark, I tried that and it works for larger size bores. What do you > > recommend for smaller bores? Iceman >The usual method is to drill undersize and then use a reamer. The rule of thumb for finish-reamed holes it to drill 1/32" u/s, then step up to 1/64" u/s, then finish-ream at the appropriate speed and feed. -Rich Parker -------------------- Date: Thu, 23 Aug 2001 12:55:29 -0500 (CDT) From: dswrx~xxwebtv.net Subject: centering... This is most likely "old hat" to most of you, but here is how I establish the center on round work... for instance, I want to make a threaded clevis for the end of a valve rod. Select stock that is a bit larger than the major diameter of the clevis... Chuck it into the 3-jaw chuck... Mount a center into the tail stock... (make sure the ways are cleaned and oiled) Turn on the lathe, and while stock is rotating, push the center into the work. This will establish the exact center of the stock... Replace the center with a center drill in a tail-stock chuck. Drill a shallow hole in the stock... Use progressive sizes of drills to bring the hole to the tap size and depth needed... Mount a shaft in the tail stock that will fit into the guide hole on the rear of the tap holder (all tap holders do not have this hole)... Use this set up to guide the tap, as you tap the hole. (don't turn on the lathe!).... Now, turn the stock to the appropriate diameter and shape. Leo (was once a beginner, now just an amateur) 8-) ----------------------- Date: Thu, 23 Aug 2001 17:21:54 -0000 From: ptolemyx~xxbellsouth.net Subject: Countersinking #2 Nut Hi- I need to countersink a #2 hex nut into a piece of aluminum. I want the countersink hole to exactly fit the hex shape of the nut (the part is too small to countersink any clearance for a hex socket driver). The part is also too delicate to punch the entire countersink in one shot. The best way I can think of is to countersink the inside diameter of the hexagon and then carefully hand punch the corners. Is there some easier or faster method? Ideally, it would also be useable in brass with #0 nuts. I'm building an armature that will be repeatedly loosened and tightened. The main issues are that a nut has to be used because the material is too soft to take the stress in a tapped hole, but the nut has to fit flush with the surface (the straightened armature joints should fit cleanly through the diameter of the armature). A hex-shaped countersink would make it easy to adjust the armature by slightly loosening the screw. -Neil --------------------- Date: Thu, 23 Aug 2001 02:05:41 -0400 From: "Rich D." Subject: Re: Countersinking #2 Nut Neil, there is no need to create a pocket that captures 100% of the nut. Only the corners are needed. Grind a good condition Allen hex wrench to a sharp square end and tap this into the hole. Try a #11 (0.191") hole. Clean out the burrs and tap in again. RichD -------------------- Date: Fri, 24 Aug 2001 20:47:23 -0000 From: ptolemyx~xxbellsouth.net Subject: Re: Countersinking #2 Nut Thanks RichD, Nick & Felice -- that gave me enough to get started. The method I'm working from now is to use a 2-56 nut filed sharp. I thread this on a 2-56 screw and pass it through the hole in the part so that the head end feeds through the hole in a jeweler's anvil. This holds the nut square in my undersized countersink while I tap it in with a ball peen hammer (periodically removing the burrs). The slight reaming of the hole by the machine screw is not a problem since I need clearance in that hole anyway. -Neil --------------------- Date: Tue, 04 Sep 2001 00:39:50 -0000 From: ballendox~xxyahoo.com Subject: Re: Newbie Question of the Day --- In sherlinex~xxy..., buchnerbx~xxy... wrote: > Todays question is do I need to center punch for a center drill? Also > what size center drill do I use? Should it be smaller than the drill > or larger? Bruce Buchner The center drill is designed to be rigid enough not to deflect, so NO, you don't NEED to center punch before using it. HOWEVER... The center punch is used to locate the precise position of the hole location (often using a wiggler or the "pointy-end" of an edge- finder). So, you "may" need to use the center punch to DETERMINE WHERE to use the center drill... As a side note: If you are, as you say, a newbie; I'd suggest using a center punch on all holes until you gain some experience. I have seen more than a few parts messed up by someone who feels they can just "trust" the handwheels and count turns (no dro or cnc is assumed here). Being human will getcha, IMO. There is a comfort of seeing the center punch come into position exactly below the spindle tool as you "dial to" the correct location... And also a comfort when you have "dialed to" the "correct" location and it ISN'T... Which is when that "extra effort" of center punching the layout earns its keep... The center drill depression must be LARGER than the diameter of the drill to work as designed. The idea behind the center drill is to guide the "real" drill by its outer flutes (which are what makes the hole) rather than the drillbit geometry at the center of the drill. Obviously, to do this the "cone" hole left by the center drill must be larger than the subsequent drill bit. Having said this, the use of split-point, stubby (also called screw machine length) drill bits will often eliminate the need for center punching ALL holes. But walk before ya run, okay? Hope this helps. Ballendo ---------------------- Date: Tue, 04 Sep 2001 01:00:53 -0000 From: ballendox~xxyahoo.com Subject: Re: Newbie Question of the Day --- In sherlinex~xxy..., ptolemyx~xxb... wrote: > Also along these lines, I always have trouble drilling holes > crosswise through small, round stock such as 1/8" brass. The tiny > bit of wander where the bit hits the curved stock gets multiplied as > hole progresses. -Neil Neil, Please read my previous response. A few additional points: 1) Be SURE you are EXACTLY centered over the material to be drilled. 2) Use a guide block postioned above the rod. This way , you can be sure that the hole is in the correct position BEFORE it enters your part. also, the flat top of the guide block will allow you to use the techniques of my previous post, and being flat, will reduce wander. this techinique will also allow drilling holes off-cneter through round stock. To make the guide block, simply drill (or bore; depends on accuracy needed) tha MATERIAL size through TWO similarly sized blocks (of similar or harder material, if the hole is off center). Now slot with a hacksaw or slitting saw, BENEATH the material hole. The slot allows the guide block to compress aound the material to be drilled; holding it well, and the use of two blocks makes it easier to set up in the mill. 3)You may want to look at what type of tooling you are using. Trying to drill through round stock with a standard hss twist drill bit can be trying... And you are not the first to deal with this frustration! A "standard" twist drill is NOT designed for this type of work! So learn from others. Clockmakers and other trades have designed specific tool geometries for this type of drilling (spade bit, for example) Carbide is generally stiffer than HSS. 4) Don't use a "drill" at all! "Drill" with a center cutting endmill. Before you say, "But the holes I am drilling are too small to get endmills for" be sure to check COMMERCIAL tool distributors. In other words, go beyond the standard mail order distributors, who do not carry everything. Again, you are NOT the first to experience this problem! 5) You mention the unsightly nature of a "flattened" area around the hole. Try "spotting" with an endmill, then drilling on the circular flat area produced. Carefully done, this can look very nice, indeed. Be sure your structural needs are not compromised by the sharp corners remaining with this technique. Hope this helps. Ballendo ----------------------- Date: Tue, 04 Sep 2001 22:22:15 -0000 From: gartner1x~xxhome.com Subject: Re: Newbie Question of the Day Here's a technique that I kind of stumbled across: 1) First, I scribe the location of the hole on the material; then mount it in the vice under the mill (used as a drill press). 2) Put a small center drill in the chuck and lower the drill to just above the material (not quite touching). 3) Using a small magnifying glass or loupe, I move the X and Y axis, until the drill is centered on the scribe marks as closely as possible. 4) Lower the drill until it just touches the material and give the motor pulley a turn or two by hand, just enough to make a mark in the material. 5) Lift the drill, and check to see where the mark from the drill is, then adjust the X and Y accordingly and repeat step 4 as necessary (I've noticed that if a small enough mark is made in step 4, any repositioning will eliminate the slightly off previous mark). ------------------------------ Date: Wed, 19 Dec 2001 12:39:19 -0600 From: "R and J Sport" Subject: Re: deep hole drilling From: > Jim, I agree that more barrel wall thickness is better. My problem > is I have no way to determine how deep the pitting is without boring > it out. Any ideas on that problem, what do you think of my proposed > drill? Thanks for your time. SteveB Steve I started making muzzleloaders in 1969 and learned form the old timers. Some of my tooling came from Bill Large and V M Starr and I got a lot of tooling from the old Green River Rifle works in Utah. Greg Roberts is a friend of mine and I have worked for him. I am a cranky old fart when it comes to muzzleloaders as I build HISTORICAL REPORDUCTIONS and don't have much use for some of the plastic junk that is foisted off on the public as a muzzleloader. That said we will start on your problem. In the old days and right up till today there are still people thaqt can make a bbl and rifle it without fancy tools. You can drill and ream a shotgun bbl wit just hand tools if you are willing to spend the time. First will the gun make a good shotgun or do you just want something to go bang. If you throw the gun to your shoulder and can look straight down the top of the bbl and everything is well centered you stand a chance. If you can't you are going to have to modify the stock to be able to hai any thing. A shotgun has to look where you do or it is just a club. In addition a shotgun for black powder should have at least a 26-28 " bbl to burn black powder well. too short a tube and you end up blowing unburned powder out the muzzle. In a shotgun you don't have a lot of pressure and some of the early bbls were pretty thin, but I like to have some good meat over the breech and will not do one with less than 1 " across the flats at the rear. I don't think ther is anyone who will bore and ream a tube on the cheep as this takes time to do right. I do this regularly in restoring antique guns and in re choking, but it runs about $100 a bbl and I have all the work I can stand. ( I am a Chief of Police full time and do restoration and repair part time) As for Re cutting I will tack on a note I sent to another fellow at the end. I have made old style reamers myself and I hav a full selection of reamers here in the shop. I just use a seriese of drills to take the bbl down to smooth, but I have a couple of big lathes to do it on. You can do this by hand but you need to go slow and just take out about 1/64th. at a time if you are doing it by hand. This means a couple or three different drill sizes at least and I like to work from breech to muzzle. Reaming can be done with a hand made square reamer and then finished with various grades of emery cloth in a home made lap. Expect that this job will take a couple of days and you can do it. IF you want to stick this kind of labor into this kind of gun. If you send me your snail mail address I will send you copies of some of my notes and books on re rifling and reaming. Jim at R and J To recut a bbl in the old days they used a method that re cut one groove or land at a time. I learned this from V M Starr in South Dakota many years ago. Basicly you take a hickory rod and cut a square section on one end and put this about 1 1/2 " into the damaged or worn bore. You cast a lead or pewter section around the rod and this is your guide. Then you cut out one groove and replace it with a cutter blade made from an old file. The remaining cast grooves serve as a guide and the one cutter is shimmed and pulled through each groove in turn to re cut the grooves. You must do this with the same # of shims in each groove as you want to cut them all the same. Next you do the same thing with tha lands taking off only enough the get rid og the pits. It takes about a day to do a bbl. but a bbl re cut or FRESHED this way will shoot like new. Mostly you are only taking a few thou. out, just enough to renew your rifling. It works and the cost is minimal but it will not work with the modern swedged rifling, only cut rifling. the swedging button work hardens the bbl. I was told the proper name for this tool is a slick. I have diagrams of some of these tools and I have a note from Bill Large showing how to sharpen the cutters I have done this and it works. If you are carefull a bbl so done will shoot as good or better than new. None of my notes or diagrams are in a format that will go in an E mail but if you are interested send me your snail mail address an I will send you some stuff. -------------------------------- Date: Sat, 29 Dec 2001 09:37:13 -0800 From: "Carol & Jerry Jankura" Subject: RE: drilling round bar stock George: Did you use a center drill to provide a starting location for the drill? >From your description, I'm guessing that you simply tried to push the drill into the steel. One procedure would be: 1. Mount round stock in 3-jaw chuck, 4-jaw chuck, or collet. 2. With Right Hand cutting tool, face off the end surface. 3. Attach chuck to tailstock; mount center-drill; drill center hole 4. Demount center-drill, mount 1/8 inch drill; drill hole; or 4. Demount center-drill, mount 3/32 inch drill; drill hole; 5. Demount 3/32 inch drill; mount 1/8 inch reamer; ream hole to final size. In general, a drill will give you neither a round hole, nor a hole exactly the drill size. So, if you simply need clearance, you'd use a drill to make the final hole. If you need precision, you'd drill the hole slightly undersize and then use a reamer to enlarge it to final size. In any case, be sure to use sufficient lubricant to keep the bits and reamer cool. If you allow the tools to become too hot, the cutting edge will dull faster than it should and you'll have difficulty keeping a sharp edge afterwards. -- Carol & Jerry Jankura ---------------------- Date: Sat, 29 Dec 2001 10:44:36 -0800 From: "Nicholas Carter and Felice Luftschein" Subject: Re: drilling round bar stock Excellent post Jerry! One other tip: If you don't have a combined drill/countersink or center drill yet, and are waiting for MSC to deliver one, you can make a lathe boring tool which will cut the center hole, and allow drilling to continue. Basically it is a 1 flute drill, with a 60 deg. angle. A tool like this allows you to clean up off center holes as well. See our web pages http://www.cartertools.com/nfhome.html -------------------------------------- Date: Sat, 29 Dec 2001 11:05:26 -0800 From: Dave Martindale Subject: Re: drilling round bar stock Jerry's instructions are good. However, it's probably worth pointing out that a drill simply doesn't make precision holes. You can use a center drill to start the hole, which will start you out on the center axis of the headstock, but a drill may still wander off slightly while cutting. In addition, the tailstock is never perfectly aligned with the headstock, so the hole may be slightly tapered, and the edges of a drilled hole are always somewhat rough. If you follow the drill with a reamer, you'll get an accurately round hole with smooth sides, but the reamer will follow the drilled hole and also be slightly off-center and tapered, particularly if you hold the reamer in the tailstock chuck. If you really need a hole to be accurately centered and parallel to the headstock bearings, you need to add a boring stage, using a single-point boring tool. It always cuts a hole that's concentric with the headstock bearings, and the hole will be parallel as long as the headstock is aligned with the ways. I found this out the hard way while trying to make a collet for a router, where the hole must be accurately concentric with the outside of the collet. To get the accurate hole I needed, I center drilled, then drilled about 1/16 inch undersize, then bored about 0.010" undersize, then reamed. (It took me 3 tries to figure this out - I'm new at this too). Dave --------------------------- From: Alan Marconett KM6VV Date: Thu Jan 17, 2002 6:06 pm Subject: Re: Screw Machine Drills jeastwoodlm wrote: > I bought a set of #1-#60 from Travers, part #01-071-901 for $28.10. > They are just what right size; I too have been continually frustrated > by drills that are "too long" for the Sherline mill. > I've even cut a couple of my standard length drills down with a hack > saw, but that's a quick way to use up a blade. > --- In sherlinex~xxy..., "buchnerb" wrote: > > A recent post mentioned using screw machine drills since they are > > shorter. Does anyone know of a socurce of sets for these drill. I > > have only seen them sold individually or in multiples all of one > > size. I would really like to get a set of them with a case so I can > > keep track of them. Bruce Buchner Hi Bruce, list, I have been using the tailstock chuck from my EMCO C5 lathe as a drill chuck in the mill for many years. Used all the bits I wanted from my 1-60 numbered set. Never thought much about it. It doesn't have a drawbar. Works OK. It's now back out on the lathe (downstairs). I recently bought two of Sherline's drill chucks, the 1/4" and the smaller one. They both have nice drawbars. then I noticed that the drill bits don't go in very far! NO WAY I'm going to cut off drill bits from the (Sears) set. I do also have some packs of jobber's bits, when I remember to use them! Better idea, as they are shorter, and easier to replace! I'm still trying to get a few replacements for the drill bit set (well, it IS 35 years old). Alan KM6VV -------------------------------- From: "Craig Libuse" Date: Fri Jan 18, 2002 12:00 pm Subject: Re: [sherline] Re: Screw Machine Drills > The taper mount #0 Jacobs are another story (got to ask Craig > if I can buy a 0MT-0JT arbor seperately). Marshall We don't list the 0JT adapters in the replacement parts price list because we sell them already pressed into the 0JT 5/32" chucks; however, they can be purchased separately. The 0MT to 0JT adapter is P/N 10160 ($5.50) and the 1MT to 0JT adapter is P/N 10170 (8.75). They are both in stock. Out of curiousity, what would be your projected use for a #1 Morse to #0 Morse adapter? I assume that is a male #1 to a female #0? Craig Libuse Sherline Products Inc. ----------------------------------- From: "Marshall Pharoah" Date: Fri Jan 18, 2002 10:56 pm Subject: Re: [sherline] Re: Screw Machine Drills From: "Craig Libuse" > Out of curiousity, what would be your projected use for a #1 Morse to #0 > Morse adapter? I assume that is a male #1 to a female #0? > Craig Libuse Sherline Products Inc. I have several #0 tapers I made to hold center drills, deburring tools, and such. It would be nice to use them in the spindle of the mill. I could just make up another set with a #1 taper, or I could probably make up the adapter myself. I've been considering making up several more #0 tapers while the compound is set up. These I would use for mounting drills into, giving me a little more room since I have the short bed lathe. Thanks, Marshall ----------------------------------------- From: ron ginger Date: Fri Jan 18, 2002 10:04 pm Subject: Re: Screw Machine Drills There was a discussion here several months ago about these, and I found a sale at one of the suppliers and got both the fractional and number sets. They have become my favored drill for all machines, even the larger ones where length is not a problem. They are considerably stiffer because they are shorter, and often I can drill holes without a center drill first. Every Sherline owner should get a set of screw machine drills, but watch for a sale, dont pay the $109 for a set. They do go on sale, just not very often. ron -------------------------------------- Date: Sat, 02 Feb 2002 17:34:29 -0000 From: "stevenhkb" Subject: Re: Oval Holes If its an oval hole in thin plate or sheet, clamp a piece of suitable material to the plate top and bottom so you have a face at right angles to the drill bit. Mount at a suitable angle (a trig problem I don't want to get into) and drill with round bit. The resulting hole drilled thru the plate will show as a elipse. It the plate is thick, you will have angled sides, which may or may not be a problem solvable by a small round file. What is the exact problem, is the hole a true elipse or to suit some piece of metal? Steve ---------------------[HUNLEY REPLY ] BTW. To those who replied to the oval hole inquiry. The oval hole is actually an elongated hole that is needed for a gimbal to pivot back and forth a bit, a shaft that passes thru changes the angle of attachment. It's the top part of an elevation devise used to aim a BP cannon. I'll be happy to send a PIC to anyone that request one. I'm going to reengineer the device using a 'ball' due to a space problem. Thanks in advance. Hank, Street, Maryland > HUNLEY31x~xxaol.com... wrote: >> I've searched the Atlas/Craftsman website and can't find what I need. I'm >> not sure It's working right. Anyway, I think a couple of weeks ago someone >> posted directions for drilling oval holes. Never in my life I thought that >> I'd need this information, but here I am with a need. Does anyone remember >> the post and can point me in the right direction? ------------------------ Date: Mon, 11 Mar 2002 09:14:50 -0700 From: "Ron Shaw" Subject: Drilling problem I have been attempting to drill and later internally thread the end of a 1mt-2mt adapter so that I can use it with a 3/8-16 drawbar. I cut the tang off the adapter, mounted it in a three-jaw, indicated to run true within plus/minus .001, put a steady on the end to be drilled, faced it flat, spot drilled, and started drilling with drill bits held in a drill chuck mounted on the tailstock. Drill bits are cheapo imports, but new. Started drilling with a 1/8", which made it all the way through, about 3/8", with some difficulty. As I have been creeping up on the 5/16 tap size, I have run into increasing difficulty drilling, and chewed up about 3 bits in the attempt. It is as though the adapter material has become super hard about half way through, and the drills will not touch it. Screams like a banshee, and no cut, even with a brand new bit. Cutting lubes don't seem to have any effect on it, neither does speed/feed. What's up with that? Work hardened material? Crappy drill bits? Have I forgotten something elementary in the setup? Any suggestions? Ron Shaw ---------------------- Date: Mon, 11 Mar 2002 10:48:58 -0600 From: Guy Fuller Subject: Re: Drilling problem I would say that it is case hardened. As a last resort you could heat it to a cherry red with a torch, if you dont have access to a furnace or a forge, and set it aside to slowly air cool. That will soften the metal so it can be drilled. When you have finished machining it, to harden it again heat to a cherry and quench in cool water. This rapid cooling will harden the metal again. Hope this helps. Guy F. ------------------------ Date: Mon, 11 Mar 2002 11:57:52 -0500 From: "Ebower" Subject: Re: Drilling problem Ron, I have tried to use sleeves as well. What you have is a "hardened thru-out" Sleeve. These are the most common sleeve that is offered. You can get "Soft" sleeves but there is only one or two suppliers. Also, your drills are cheapo style. I have been using cobalt drills to do most of my drilling. You will have problems when it comes to tapping. You have not work hardened it. You should have cut the sleeve off above the knock out slot. You would then be up high enough to tap it. How are you going to use them? The drawbar should go into the taper end that you will be using, (e.g. the # 2). Earl bower machine ebowerx~xxlcsys.net ------------------------ Date: Mon, 11 Mar 2002 18:30:36 +0100 From: "jcgerb" Subject: Re: Drilling problem Not forgetting that hardening will slightly change the dimensions and/or the shape of the taper. Normally they are grinded after the thermal treatment. Jean-Claude, Switzerland www.homestead.com/turnandmill ------------------------- Date: Mon, 11 Mar 2002 12:12:19 -0600 From: jmark.vanscoterx~xxamd.com Subject: RE: Drilling problem There have been times in the past when I ran into problems like this. For metal that was too hard (and a pocketbook that was too small), I used masonry bits to enlarge the hole. The bits have a piece of carbide at the end and I have cut through a hardened leaf spring with them. Mark V.S. in Austin, TX ------------------------- Date: Mon, 11 Mar 2002 14:32:57 EST From: Skaw5x~xxaol.com Subject: Re: Drilling problem If it is an old mt sometimes the steel when it was heat treated for hardness, wasn't heat treated properly, I would suggest running a carbide drill at low rpms. Try using pledge (that's right furniture polish) as a lubricant. I know of tool grinders that cut out high speed taps with carbide drill & pledge as a lubricant. If you are having trouble drilling it, you are going to have trouble tapping it also. You might want to go a little bigger on the tap drill. Another good lubricant that we used to use to cut rough titanium billets was Crisco lard. The scale on a billet was really hard, but once under the scale it cut allright. Scooter ------------------------------------ Date: Sun, 17 Mar 2002 20:19:30 -0000 From: "toddfoh" Subject: Re: Making a "D" hole --- In taigtoolsx~xxy..., Bill Brady wrote: > Help! I need to make some handwheels that will go on an existing shaft > which has a flat on it. So I need to make D shaped holes. Three possibilities: 1) Make a round hole and use a setscrew on the flat of the shaft. 2) Make a round hole and make a second D shaped piece to fit in the void. Glue everything with epoxy. 3) Make the handwheels clamp to the shaft with a second straight clamp piece that clamps across the flat of the shaft. Todd F. ------------------ Date: Sun, 17 Mar 2002 21:46:14 -0500 From: Stan Stocker Subject: Re: Making a "D" hole Hi Bill; A couple of things come to mind. Unless the shaft is very large, cutting the D opening is probably not going to give a really good fit. You could mill a piece of rod the same diameter as the shaft down to make a D shaped filler piece, and clamp this with a set screw. This will give a nice no shake fit and allow the handwheel to run true to the shaft. The D shaped filler piece could be secured to the handwheel bore with bearing retainer compound or epoxy alternatively, using a setscrew opposite of the filler piece on the handwheel. If you do this, you might want to drill a small hole or two through the handwheel and into the filler piece, and secure with pins retained with Loctite, or at a minimum give a little more holding area for the epoxy or bearing retainer. This would help keep things from shifting. This is probably overkill, a simple dimple to take the tip of the setscrew is probably enough to keep things in place. Another option is to make a duplicate of the shaft, wither of nicely polished aluminum or better yet delrin or nylon. Coat with release compound and fill the void in the degreased handwheel with JB Weld or a steel or titanium filled epoxy, using the duplicate shaft piece as a form. Quick and dirty option would be to use 2 setscrews in the handwheel, one bearing on the flat, and one at 90 degrees to the flat. I'd see if the quick and dirty option was acceptable for the application, if not I'd go with the filler piece in the handwheel bore in preference to the epoxy fill approach. If you go with an epoxy, don't use one of the hobby epoxies for model building, they tend to creep in shear. Great for model airplanes and boats where the weight is allowable, wrong stuff for this sort of application. Either a metal filled epoxy or JB Weld would work well. These set very hard. If you are not familiar with JB Weld, it can be filed, milled, and take threads. Useful stuff to have around. Most auto parts and hardware stores have it. Take care, Stan ------------------- Date: Mon, 18 Mar 2002 13:00:35 -0000 From: "toddfoh" Subject: Re: Making a "D" hole Well, there are a few answers to that question. It really depends on the application. 1) If you are making parts in volume, you can cast or mold the parts. Most knobs or handwheels with a D-hole are made this way. 2) On a sheet metal part, you could punch it. 3) If it is a through hole, you could either wire EDM the hole (leaves a small radius in the corners) or make it with a custom broach. 4) In a blind hole, you can CNC machine it with a tiny diameter end mill. You might have to hand scrape or file the corners to get them really sharp. Or you could electrode EDM it. This is where you make a graphite electrode in the shape of the hole you want and plunge it very slowly into the metal. The metal is vaporized and you are left with the D-hole you want. As a designer, if I absolutely had to have a blind D-hole to mount a handwheel to a shaft, I'd probably design an insert with the hole wire EDM'd into it. Then I'd press it (or clamp it) in a round blind hole in the handwheel. Todd F. ------------------------------ Date: Mon, 18 Mar 2002 18:45:39 EST From: tadici283x~xxcs.com Subject: Re: sensitive drilling attachment In a message dated 3/17/2002, benedictx~xxaustin.rr.com writes: > > Has anyone made a sensitive drilling attachment for the Taig. > > Sherline has one, but it appears that it will not fit the Taig. I > > have a lot of very small holes to drill and something like this looks > > good. I do not want to drill out the headstock bore to fit the > > Sherline. Any suggestions? I have built a micro feed tailstock, go to Nick Carters web site to read about it, I have mentioned this before, but what I did is mill out the center section of the standard Taig tailstock and place in Taigs crosslide in between so that you have both crank feed and ram style feed and it effectively increased the total tailstock movement to greater than 3 inches, this was needed because I could not get "gentle" enough feed for my watch making and repairing projects, my headstock is able to move to the tailstock rather than move the tailstock up to the chuck or collets this gave me room for my big hands to clear the end of the lathe bed. I have to say that getting the new tailstock aligned with the headstock was more than a pain, watch making requires super close tolerances, and even to my surprise the Taig performs at near watch maker lathe tolerances. My motor is mounted on the Taig headstock just like the mill but is mounted to the rear behind the lathe so new brackets were needed to be made, I have tested this system, there is not a problem with the motor deflecting the headstock with the motor's weight or dynamic stress, Taig builds a generous overkill machine. Chris DiCintio of Bradenton FLA ----------------------------- Date: Tue, 29 Oct 2002 14:43:52 -0800 From: Alan Marconett KM6VV Subject: Drilling angled holes Hi to the list, I'm working on the cylinder for the Stuart steam engine, and I have some angled holes to drill. The first one is on a simple angled surface, looks like about 77 degrees (near perpendicular). I will of course set up on the adjustable angle plate, but I'm wondering whether to use a center drill to start the hole, or to first use an endmill to get a flat. The second one is about 55 degrees, but it goes into a corner! Small hole in the case of the corner, about .098". The first one gets a 1/4"-32 thread. Both these holes must "break out" into other machined passages. I'm working in aluminum FIRST, until I'm satisfied my setup is OK! And to boot, I'll get parts for a second engine! Alan KM6VV May the Swarf be with you! ----------------------------------- Date: Wed, 30 Oct 2002 01:47:14 -0000 From: "n2562001" Subject: Re: Drilling angled holes Alan I have always had the best luck when first spotting with a center cutting end mill. I then use a center drill or a spade drill for spotting before drilling. Jerry Kieffer -------------------------------------- Date: Wed, 06 Nov 2002 17:53:44 -0000 From: "n2562001" Subject: Re: drilling on lathe [SHERLINE GROUP] > I need to drill a hole in a 7" X 1" X 1" piece of aluminum. I do > not have enough room on my mill to do this so the lathe is the > next choice, but what is the best way to do this? There will > be two holes, both off center. I have only +/- .001 error on this part. > Thanks, Devin Devin It sounds like you are trying to drill holes in the end of a one inch square piece of stock. If so your best chance at proper hole posioning will be with the mill. Turn your head in the horizontal position and put a three inch high piece of whatever under your vice and reclamp to the mill table. You can then hold the stock in the vice and easily position your holes. I just drilled in the end of something three feet long and it worked great. Jerry Kieffer --------------------------- Date: Wed, 6 Nov 2002 13:29:49 EST From: Holyelvisx~xxaol.com Subject: Re: drilling on lathe This is a good idea but, not enough room for this one. The stock is 7", vise 2", 3-jaw 1.5. I believe the room on the 5400 mill is 8". Thanks, Devin --------------------------------------- Date: Wed, 06 Nov 2002 12:46:39 -0800 From: Alan Marconett KM6VV Subject: Re: drilling on lathe Hi Devin, 7" x 1" x 1"? and you can't do it on the Sherline mill? I'll assume you're drilling into the side(s) of the stock, not trying to drill the ends? I'm thinking your drill bits are too long? It it IS into the ends, then you can probably rotate the spindle to a horizontal position, and clamp the stock on 321 blocks to get them up off the table. Standard "drill index" sets have drills about 5" or so max length, which I routinely use in my Sherline mill. How big are the holes? The boring tool will take you up past something like a 3/8" dia hole, If I recall correctly. I have bought "jobber" bits which are shorter, or cut off/ and turned down the shanks of drill bits to fit my mill/lathe. You can turn the ends of the drill down with HSS in the lathe (just don't let them heat up and harden). IF you need to do it in the lathe anyway (guess you have an 8"+ lathe), then mark the holes, center find them with the part in a 4-jaw chuck or faceplate, and a drill bit in the tailstock. Recent posts on this list on drilling off-center holes in the lathe suggested using toolmaker's buttons. Or indicating in from known edges of the stock to be drilled. Next time this comes up for me, I'm going to locate and drill/tap holes at my locations in the mill, and then used buttons that I've turned and threaded true. Then I can thread them in at the required hole locations, and use a dial indicator to "clock" them in on the lathe. Tell us a little more, I might have missed something in your question! Alan KM6VV ----------------------------------- Date: Wed, 06 Nov 2002 21:43:14 -0000 From: "lan_brooks" Subject: Re: drilling on lathe A couple more suggestions for using your mill 1) Screw machine drills, also called stub drills are shorter and could provide more clearence and are readily available from MSC and others. 2) If the hole size is under 1/4 in, use the sherline MT1 milling collet to hold the drill. A temporary reducer could be made with a piece of 1/4 in round bar stock with the right size hole in it for the drill and then slit on one side so it can close when the collet closes. If the hole is over 1/4 inch still use the collet and get a 1/4 in shank drill shortened and sharpened as necessary. 3) If you are drilling in the end and want to use the lathe, make the part a 1/4 longer, chuck in a 4 jaw chuck center as accuratelly as possible. and using a REAL SLOW SPEED so the part does not stand a chance of going anywhere if it does come out, center drill the end. Then using a live center in the tailstock turn a 1/4 in wide round shoulder on the square stock. Use a steady rest to hold the material on round shoulder and drill your hole. Remove the round shoulder with a saw and square up the end. I used the same basic procedure on a piece of rough round stock that was going to be drilled and turned. You are not going very deep with the center drill and if the speed is kept low, the stock will not go anywhere. ----------------------------------------- Date: Wed, 6 Nov 2002 17:00:21 EST From: Holyelvisx~xxaol.com Subject: Re: drilling on lathe Alan, I am drilling the stachions for the overhead cams for a V8 engine. I think turning the head horizontal and putting the vise on some sort of riser block would be the perfect solution.(I am not comfortable chucking up square stock for such close tolerances esp. when the stock is so long.) Devin ------------------------------------- Date: Sun, 08 Dec 2002 19:14:44 -0000 From: "iamstarvin " Subject: "chatterless" countersink Has anyone found a really chatterless 82 deg. countersink that will countersink a no.6-32 screw. All I have tried chatter at the very end of the job. Any help would be appreciated steve Livermore Ca. --------------------------------------- Date: Sun, 8 Dec 2002 14:30:58 -0500 From: "Dan Statman" Subject: Re: "chatterless" countersink The obvious solution is turn down your spindle speed so that the chattering stops. Any bit will chatter at the wrong speed. The art is finding the speed that it still cuts at, and does not chatter. Experiment with it, and I bet in 5 minutes you will be an expert. Daniel J. Statman, Statman Designs www.statmandesigns.com dan.statmanx~xxrennlist.com ----------------------------------- Date: Mon, 09 Dec 2002 01:54:20 -0000 From: "Donald Clement " Subject: Re: "chatterless" countersink I find that M A Ford makes a single flute countersink that doesn't chatter. http://www.maford.com/taf/catalog.taf?category=a11 Don Clement Running Springs, California Owner: Clement Focuser ------------------------------------- Date: Mon, 9 Dec 2002 22:01:02 -0000 From: "Ted Walls" Subject: Re: "chatterless" countersink I have a number of countersinks. Some home made, some single flute, some with 3, and some with 5 flutes. I don't find any problems with chatter using any of them. The secret is to keep your speed down. the slower the better, and use some lubricant. I find Rocol RTD paste is about the best for countersinking ops. A small amount applied with a brush to the cutting edges of the tool works wonders. If it smokes you are going at it too hard (using too much pressure) or you revs are too high. hope this helps. ------------------------------ Date: Thu, 12 Dec 2002 21:54:30 -0800 From: "Orrin B. Iseminger" Subject: Re: Drilling At 08:40 PM 12/12/2002 -0800, you wrote: > Question, I was doing some drilling on the lathe and when I was finished > and took the part out for inspection I noticed the starting point of the > drilling was perfectly centered, but the back of the part that I was > I read the > book and made sure the part had support from both the chuck and steady > I also center drilled the start of the hole so the drill would have > a clean place to start.... > I drilled for a total distance of 3.5 inches > I also made sure to stop ever quarter to half an inch to > I used a dial indicator on the part to make sure it was > I used the drill chuck to > Any help would be great as I try to think of were I went wrong. Welcome to the real world. You probably didn't do anything wrong. Drilling a deep hole, straight, is a challenge for even the best of machinists. There have been numerous threads on the topic on the Home Machinist forum: http://www.chaski.com/cgi-bin/machine_index.cgi Generally speaking, if you need to have a hole straight down the center, do this: 1. Drill the hole first. 2. Mount the piece between centers. 3. Turn the OD. That way, the hole and OD will be fairly concentric. You're not guaranteed of having a straight hole, however. Drilling is a crude process, one of the more inexact machining operations. Orrin Orrin B. Iseminger Colton, Washington, USA So many projects, so little time. http://users.moscow.com/oiseming/lc_ant_p/index.htm -------------------------------------- Date: Fri, 13 Dec 2002 04:59:00 -0800 From: "Orrin B. Iseminger" Subject: Re: Drilling Make your own dog for large diameter stock. Mine is rather crude, but I just used the materials on hand. Seeing as how it works well, there doesn't seem much need to improve upon it. Cut two lengths of key stock and mill a vee-notch in the side of each, off center. The vee-notches will engage the cylindrical shape of your work piece. Then, drill and tap them with two holes, one on each side of the vee-notch. The holes must be far enough apart to straddle your work piece. Use long screws to clamp your keystock dog onto your work. The reason the notches are off center is to have a leg sticking out to the side. You can drill and tap one of the legs for a long screw that acts as a dog to engage the faceplate; or, drill and tap the faceplate for a long screw that will engage a leg that sticks out. Obviously, some of the holes in the key stock will be tapped for the clamp screws and some will be drilled oversize to allow the screws to slide through the hole. I made my dog with a long leg sticking out on each side. That way it is balanced and will not cause vibration at high RPMs. Orrin ----------------------------------- Date: Sun, 19 Jan 2003 16:09:19 -0800 From: "Scott A. Stephens" Subject: Re: Re: How can I make a 1" dia hole, 5" deep? At 08:32 PM 1/19/2003 +0000, you wrote: >Scott, I would like to see your pictures. Ideas come from a lot of different >sources, and although you probably don't realize it you've already >given me something to think about. If you have the time, would you >describe your "line-boring" setup in more detail? I'm interested in >the details of your between centers boring bar. Did you buy or build, >what kind of cutters you use, stuff like that. I haven't had need for >that kind of setup as yet but I can see it coming, and would like to >put something in place in advance of that day. Thanks, JBK I got the idea from Jose's video's. Since I had not done it before and only saw pictures of Jose do it, I started with material I had on hand. First the cutter, I used a broken 1/8 drill bit. Believe it was made of HSS. I ground this to a point with a slight hook to break the chips. Next I had some 3/8 rod. I drilled a hole 1/8th hole for the cutter to go threw and then drilled a hole for the set screw. Once done I put it on the lathe and center drilled the ends. Problems encountered. Chips, originally I had a problem with chips staying in the hole. after they had been cut. I used compressed air to blow them out. That was a mistake since they went everywhere. Also I sprayed in WD-40 to help with the cutting and chatter I had a problem with. But once I found the right speed and feed chatter went away. But I would still spray in WD-40 before each in stroke and out stroke. I would run the cutter threw twice, an in and then an out stroke before I would advance it. Also I always touched the HSS up with a stone to keep it sharp and cutting. I only used this setup till I had the hole opened up to about .66. Then I switched over to the 1/2 inch bar with 1/4th cutter to bring it out to 1 inch. The half inch with 1/4th cutter was more ridged and seemed to cut better. I still had problems with chips staying in the hole while it was small. When I do it over again I plan to use a vacuum to remove the chips instead of compressed air. ------------------------------------------------- Date: Sun, 19 Jan 2003 18:27:24 -0800 From: "Scott A. Stephens" Subject: Re: Re: How can I make a 1" dia hole, 5" deep? At 02:00 AM 1/20/2003 +0000, you wrote: >Thanks, Scott. I'm going to make a couple of different sized bars >along these lines and have them ready for a "real" project when the >time comes. How did you attach the bars to the headstock? Did you >chuck them or use the dead center/dog approach? It probably doesn't >make any difference, but I'd be interesting in knowing what worked >for you. Also, how long did you make your bars? JBK You can do either. I used the dog. Since I had just gotten the tail stock to .001 and was setup for that. My bar was about 14 inches. I can go measure it to give you a precise number. ----------------------------------- Date: Mon, 17 Mar 2003 14:33:03 +0100 From: Roger Jonsson LINE AUDIO Subject: Re: PCB's >In a message dated 3/16/2003 10:24:34 AM Pacific Standard Time, >frazzxrx~xxyahoo.com writes: >> Has anyone used a CNC to make PC Boards? What tool do you use, a >> regular (but very small diameter) endmill or are there other tools to >> use in the end that would be better? Hi, You should use Tungsten Carbide highspeed drills. (Steel drills will loose shapness very fast and make bad cuts.) These are available from most suppliers of electronic components. They are usually 1/8" shank and are available in sizes from 1/50" to 1/8" (0.5-3 mm). These drills require high speed, atleast 10000 RPM. Don't try fasten them them with a chuck, use a milling collet or they might break! If you want to mill tracks or larger holes in PCBs, special Tungsten Cabide mills are also available from some suppliers. I only buy these in Sweden, but it shouldn't be hard for you to find if you look ask around among the electronic component suppliers. www.maplin.co.uk carries tungsten carbide drills suitable for PCB, in the UK and ship worldwide, but as I said these shouldn't be hard to find anywhere. --------------------------------- Date: Mon, 17 Mar 2003 15:08:57 -0000 From: "lan_brooks" Subject: Re: PCB's Carbide router bits are used for the profiling and carbide drills are used for making the holes. The reason for this is that the fiberglass material used for PCBs is very abrasive. Both routers and drills for PCBs can be purchased from MSC . Look for PCB Routers and PCB Drills. Have fun, Lan --------------------------- Date: Thu, 27 Mar 2003 01:01:43 -0500 From: "Ned Carey" Subject: Re: micro size drills and Jacobs chuck runout OK guys, what would be considered acceptable for a Jacobs chuck on the mill? I have some friends that say you should expect the runout to be less than 001". That surprised me, I thought runout would be more in the .003" range, although I can't remember how I came to that conclusion. Does anyone have an Albrecht chuck and have an idea of the runout? This came up on another list in regard to drilling holes in the .004-.008" range so minimal runout is crucial. Jerry Kieffer said the only accurate way to drill micro holes is with a collet. However this precludes using a sensitive type drill attachment. Does the lack of "feel" while drilling with the handwheel cause problems? Thanks, Ned ---------------------------- Date: Thu, 27 Mar 2003 18:57:29 -0000 From: "n2562001" Subject: Re: micro size drills and Jacobs chuck runout Ned: I am going to limit my comments to drilling holes under #80 (0.013"). You can get a lot of opinions on this but in the end you will have to develope your own procedures that work for you. There are three reasons I do not use a sensitive drill att. First I have never had a chance to work with one that has less than 0.001" to 0.002" runout when installed on a machine. I am sure there must be one out there someplace, but I just haven`t ran across it yet. 0.002" runout on a 0.006" drill means instant broken drill. The second reason is feed rate control. On a 0.006" or 0.008" drill you're not going to feel much until it's too late. I have found I can slowly nudge the hand wheel 0.001" to 0.002" at a time and eliminate most drill breakage from over feeding the drills. The third reason is the the time and hassle it takes to go back and forth from drill att. to end mills etc. As I said this is what works for me. There is really no wrong way as long as you get the job done. Jerry Kieffer -------------------------------- Date: Thu, 27 Mar 2003 21:43:27 -0000 From: "n2562001" Subject: Re: micro size drills and Jacobs chuck runout > Jerry, With drills this size, do you use a "pecking" method, or a > constant pressure? How often do you clear the drill? Do you do any deep > hole drilling (say 10 times the dia. of the drill deep?) Thanks, Wm Wm. There is of course very expensive equipment built specifically to drill holes in the .005" range and down that provides constant pressure on the drill. I prefer to use The Sherline Mill and Lathe to do this work because most small work pieces are machined in this equipment and I don`t like to remove them from the tooling for drilling. The Sherline Equipment may or may not have been designed for this work but has done an excellent job using the procedure I have described. For most holes under five times the diameter of the drill I use HSS spade drills. For deep hole`s I generally use Guhring micro drills. (looks like a twist drill but shorter) Depending on the drill size I generally clear the hole every .010" or so. Jerry Kieffer ------------------------------- Date: Thu, 27 Mar 2003 19:36:00 -0500 From: "John Thompson" Subject: small drills Wm, We use dremels to drill small vacuum holes (mostly #76 with some #80). We use a fast peck drilling, about the speed of what most people knock on doors, is the best speed I can describe...tap-tap-tap with plenty of lube. This is in Aluminum. I haven't tried it on any kind of press, mill, or lathe, with such small bits. I imagine it would be hard to get the feel of such an operation. Jerry might be able to tell you more John -------------------------- Date: Wed, 2 Apr 2003 15:21:52 -0700 From: "D.W." Subject: rake angle anyone? Just got started on a small pump project (PM Research). The plans state that the rake angle on drill bits should be ground to 0 degrees for drilling brass. I'd be happy to do this if I could just figure out what the heck it means. Thanks in advance, Dave ------------------------------ Date: Wed, 02 Apr 2003 19:51:42 -0800 From: Keith Green Subject: Re: rake angle anyone? Hold your drill bit up in front of you so that one cutting edge is facing you and the other is facing away. The one facing you is the one on the left. Looking at this edge, turn the drill counterclockwise 90 degrees and view the edge from the periphery in to the center. You can see that the helix of the drill causes an angle to form there down from the cutting edge. To drill brass or bronze, you want to grind a small flat there on that edge to take away the angle. When you look in from the periphery to the center the area there below the cutting edge should be parallel with the centerline of the drill instead of curving away with the helix. You'll find the drill doesn't grab at all and the chips are fine slivers(sp?). Use solvent for lube. keith. ------------------------------ Date: Wed, 02 Apr 2003 23:00:23 -0500 From: RichD Subject: Re: rake angle anyone? Hi Dave, Holding the drill vertically, point up, rotate the drill such that the eye can look **along** a cutting edge. Now you see the flute is a helix ending at the cutting edge. The angle the flute makes with the top of the cutting edge is the RAKE angle. If you now imagine that the edge is a small vertical flat along the edge, this is zero rake angle and is in fact in line with the axis of the drill. The normal rake angle of a standard new drill is suited for drilling steel and other tough material that needs more of a knife edge to get under the surface. Brass and brittle plastics will drill ok this way, but way too agressively. This is evidenced as the drill edges begin to break thru the far side. Grinding a narrow flat on the face of each cutting edge now makes the edges scrape as a cutting action. Brass and plastic machine very well this way and produce clean edges on break thru. This called dubbing a drill. The clearance angle is the angle from the edges on top to prevent the edges from dragging and allowing proper cutting action. Here are some references: http://www.tpub.com/steelworker2/121.htm http://www.desktopcnc.com/march02.htm http://www.huntfamily.com/metz/hotips6.htm http://www.newmantools.com/machines/drillpoint.html RichD ------------------------------------------- Date: Thu, 3 Apr 2003 00:20:30 EST From: catboat15x~xxaol.com Subject: Re: rake angle anyone? That is to keep the drill from grabbing the brass. I have found that a light stroke with a hone will do the job and stll leave enough of a cutting edge to use the drill on other materials. As to what it means look at the end of a twist drill and you will see there is an angle where the cutting edge meets the groove in the drill. That defines the rake angle, hard to describe, but turn the drill in your hand looking end on to the cutting edges. That is the part you want to stone or grind a small flat to keep the drill from trying to pull itself into the work. If you have a good drill press and the work well secured it is usually not needed. But don't try drilling brass with the work held in your hand as the drill will grab and you will have to count your fingers to see how many you left in the swarf bucket. ---------------------------- Date: Fri, 30 May 2003 19:19:27 -0000 From: "n2562001" Subject: Re: Quality of Sherline products? [NOTE THE DRILLING TIP FOR SMALL HOLES] I do not work for Sherline and never have. However I have been asked to help out at there booth at the NAMES show in the Detroit area the last few years. For the most part I have been asked to demonstrate the machines and get asked your question about every two minutes. To demonstrate the lathe I generally rip down a 3/4" steel bar to about a .010" pivot .200" long in six or seven passes. After that is complete I drill a .006" in the end of the pivot. this whole process takes about 90 seconds if I am not talking as usual. The .006" drills are spade drills that are ground and sharpened from 1mm HSS blanks using the Sherline rotary table and mill. I have been doing this type of work on my current machines two to three hours a day for the last ten or twelve years with no repairs or down time. I hope will give you some idea as to what the machines are capable of. Jerry Kieffer ----------------------------- Date: Wed, 06 Aug 2003 13:39:24 -0000 From: "tnance0913" Subject: Drill point Angle When looking thru machine tool catalogs I see drills bits listed as having a drill point angle of (usually) either 118 degrees or 135 degrees. Having just fallen off the turnip truck, I generally do not pay attention to this property and just buy according to price and manufacturer. Could someone please tell me what difference the angle makes in drilling and which flavor is better for what type of operation? I generally work in aluminum, brass and the softer steels, and sometimes, after an appropriate bit of loin girding, I work with stainless. I drill almost exclusively with the Shereline mill. Is one bit types better suited for my work than the other? Thanks in advance, Tom Nance Corpus Christi, TX ------- Date: Wed, 6 Aug 2003 09:05:29 -0500 From: "Ron Thompson" Subject: Re: Drill point Angle Drill point angle has to do with the material being worked. Generally the harder the material, the higher the angle number, with 118° being considered general purpose. The 135° points are for harder material and will drill slower. Ron Thompson On the Beautiful Mississippi Gulf Coast USA http://www.plansandprojects.com ------- Date: Thu, 23 Dec 2004 10:03:46 -0600 From: Ralph Ferone Subject: Re: understanding drill bits >What is the difference between the 118° and the 135° sharpening angle? > Which angle should I use? From a faq found through Google: The 118° standard (non-split) general-purpose high-speed drills are used for drilling soft or mild materials such as cold rolled steel, aluminum, and wood. A 118° drill point provides good results, but may cause "walking" at the drill point. Commonly, a pilot hole is drilled before using a standard drill bit. The 135° split-point, heavy-duty, high-speed steel drills feature a heavy web construction for extra rigidity. Use this angle with hard steels, stainless steel, titanium and other hard materials. The 135° split-point eliminates "walking" and reduces thrust. It also produces smaller chips that won't clog up the hole. Ideal for hand and portable drills where bushings can't be used. There is no need to pre-drill a pilot hole with the use of a 135° split-point drill bit. Ralph -------- Date: Wed, 24 Sep 2003 02:12:44 -0000 From: "bsswy" Subject: run out on drill press I have a 5/8" drillpress with a #3 Jacobs taper. When I put an indicator on the chuck body I get about .005" runout. When I chuck a piece of rod I know to be true, I get about .015" runout close to the jaws. Obviously it gets worse the farther you go away from the chuck. Is there anyway to true up the jaws? Is .005" runout normal for a cheap imported drill press? How do I remove the chuck if I need to replace it? I have had the drill press for about 20 years and had I known anything when I bought it, I probably would have taken it right back for a refund. I have been putting up with it all these years mainly because I would use it woodworking and it didn't really cause that many problems. Now that I got my Taig lathe and want to start machining the performance is totally unacceptable. --------------------------------- Date: Tue, 23 Sep 2003 22:42:46 -0400 From: Stan Stocker Subject: Re: run out on drill press If the chuck is on an arbor that presses up into the spindle you can upgrade the chuck. Most drill presses this size have a MT2 socket in the spindle. If the socket is off center you're out of luck though. Might remove the chuck on it's arbor (use a wedge through the slot in the side of the spindle to knock it out) and clock the bore just to verify it is concentric, and that the problem isn't a poorly fitted spindle. An Albrecht chuck on a loose spindled machine won't do anything other than put a hole in your wallet :-( In some cases, simply cleaning the arbor and socket very well and trying a few positions allows you to tune the runout to a more acceptable amount. Try a few different diameters and see if the runout is fairly constant, if it's all over the place it's almost surely the chuck. If it's fairly constant checking the bore is worth the time. Cheers, Stan ------------------------------ Date: Tue, 23 Sep 2003 16:47:57 -1000 (HST) From: Tom Benedict Subject: Re: run out on drill press Mmmmm... Yes, there's some stuff you can do. You can get these tapered forks for removing drill chucks. I've seen them in Enco and MSC. Others likely have them. They fit between the spindle and the chuck, and basically act as a wedge. If you're in a hurry, you can probably make some yourself using some flat stock, a hacksaw, and a file. The shape isn't that intricate (or that critical, as far as I've heard.) Try measuring runout on the spindle itself. If there's enough poking out from behind the chuck, indicate off of that. If not, you may need to remove the chuck first. If the spindle comes out ok, try cleaning the tapered arbor and the tapered socket in the chuck. Re-install the chuck and see how the runout is now. If that fixed it, it was likely contamination where the chuck seats onto the arbor. Next check the action of the chuck. If it's still smooth, the chuck is probably fine. If not, you can replace it or rebuild it. Guy Lautard has an excellent section on rebuilding Albrecht style chucks and Jacobs style chucks in one of his Machinist's Bedside Reader books. (I've been itching to rebuild mine!) If the chuck is ok, the spindle is ok, and the taper is ok, try cleaning out the inside of the chuck jaws. Gunk or swarf up there can throw things off. Once clean, repeat the runout test on a length of drill rod. If it's still off, the jaws may need to be reground. Here's where I start getting fuzzy. I've never done this part, so understand I'm fishing here. Hopefully someone else will have better advice: In order to grind the jaws, you'll need to close the jaws on something that still lets you get up inside the chuck with the grinder. I haven't done this. Ideally you'd like the chuck spinning and the grinder spinning. This makes for a very concentric grind, and takes out a lot of alignment errors. An alternative that probably works well for resurfacing jaws, but I would guess wouldn't do as much on alignment, was also from The Machinists's Bedside Reader: You know those ceramic rods people use for sharpening knives? This one guy mounted one in a four jaw, indicated it true, and verrrrry gently closed down the jaws of the chuck on his tailstock until they contacted the rod. After lots and lots of careful work, he basically ground the chuck true. Again, I haven't tried this so I can't say how well it works. Just on the off chance that you need to true up a chuck that goes on a threaded arbor (like the drill chucks on the Taig lathe), here's a way to make improvements without grinding any jaws: Mount some 1/2" or 3/8" rod in a collet or in the four jaw and indicated it in as true as you can. Leave about 3/4" sticking out. Mount the drill chuck in question on this, and clamp down good and hard. Use a facing tool to skim just enough material from the back of the chuck to true up the flat surface. Re-mount the chuck and check runout. I was able to get my 3/8" Jacobs chuck from 0.005" TIR down to 0.001" that way. (My 1/4" industrial Jacobs chuck has been too good for me to want to try this.) Tom ----------------------------- Date: Wed, 24 Sep 2003 12:28:20 -0000 From: "davideggy2" Subject: Re: run out on drill press Disclaimer: I don't recommend this. Having said that, I did try it once. An old timer told me to chuck a piece of 5/8" rod and give it a whack with a hammer on the high side. It worked for me, came to within a few thou. You decide, but all that other stuff sounds like a lot of work on a drill press that's been just fine so far. Dave ----------------------------- Date: Wed, 24 Sep 2003 15:27:00 -0000 From: "Joules" Subject: Re: run out on drill press That wedge thing people keep refering too is called a drift key. That should remove the chuck and taper. Inspect the taper on the chuck arbor, is it scratched,gualed or rusty. Use a small mirror and light, check the drill spindle. If that is like wise, you could try gently reaming the spindle (note:- to clean, not to re-form). This will remove the crud and level the scatches. If the arbor on the chuck is in this state, bin it, and buy a new one... If possible use a blank 3mt (I believe that is the taper in your drill) to test the spindle. The blank may need to be trued or checked for accuracy in another lathe first. Joules ---------------------------- Date: Wed, 24 Sep 2003 09:46:15 -0700 From: "Nicholas Carter and Felice Luftschein" Subject: Re: Re: run out on drill press As others have said, remove the chuck from either the arbor or the spindle if it is integral. Check the chuck mounting taper for runout, and if it shows more than .001 remove the spindle and retrue on a lathe. A Jacobs brand chuck or similar will go a long way towards eliminating runout. Finally check to make sure there is not much play in the spindle - worn bearings or the hole the quill travels in will give poor performance as well. I am a big fan of old used US made drill presses (I love my Buffalo the best, but the old Delta's are great as well) most have provision for snugging up the quill. See our web pages http://www.cartertools.com/nfhome.html --------------------------------------------------------- Date: Wed, 29 Oct 2003 19:59:00 -0000 From: "texas_hoppy" Subject: New Sherline User [HOW TO DRILL WITH A LATHE] I want to drill a 9/32 hole in a 5/8 aluminum rod using my Sherline lathe. I have the 3 jaw head and a drill chuck. Both came from Sherline along with the lathe in a kit. I have not used either one yet. I make pens on this lathe and it works great. It looks like I need to mount the drill chuck in the tail post. How do I do this and then more the bit into the aluminum rod? Do I push it by hand? This doesn't seem right to me, but... Or do I mount it some how on the tool holder? Thanks for any help, Larry Reese Kenney, TX ---------------------------- Date: Wed, 29 Oct 2003 15:14:42 -0500 From: "Statman Designs, LLC" Subject: Re: New Sherline User You should have a #0 morse taper that fits on your drill chuck, it may have come attached from the factory. This taper slides into the tailstock and is held by friction. The handwheel on the tailstock will feed the drill bit into the workpiece. If it won't feed far enough you can drill the hole as far as possible then move the tailstock by hand and then start feeding it again. Be sure to clear the chips periodically from the drill flutes and the hole. To remove the drill chuck from the tailstock you just back the handwheel all of the way out and it will pop out of the tapered hole. Depending on the length of the rod, it may need to be supported with a steady rest in order to keep it from moving off-center. You also want to center drill the piece before drilling. Daniel J. Statman, Statman Designs www.statmandesigns.com dan.statmanx~xxrennlist.com -------------------------- Date: Wed, 29 Oct 2003 21:55:41 -0000 From: "jeastwoodlm" Subject: Re: New Sherline User I agree with all that Mr. Statman said. In addition: Since you don't seem to have a lot of experience drilling with a Sherline, let me recommend that you practice a bit. It takes a while to get a feel for how to do this well. Some specifics: 1) After chucking your piece and checking it for runout with a dial indicator, chuck a center drill (#0 or #1) in the drill chuck. Move the tailstock close to the workpiece, clamp it, and advance the handwheel until the center drill makes contact. Apply a bit more pressure with the handwheel while rotating the chuck holding the workpiece by hand. This gives the drill a "start". 2) Apply power and slowly advance the center drill, withdrawing frequently and brushing away the chips. 3) Step drill with drills of increasing size to reach your final hole diameter. For a 9/32" hole, I'd start with a 1/8" drill, then a 3/16, then 1/4, then 9/32. 4) Watch for the drill chuck turning in it's socket. This friction fit doesn't work too well on such a small area; once it spins in the socket, it mars the tapers and gets more likely to not hold well next time. Make sure you've twisted the drill chuck into the taper snugly (in the same direction the work turns) before beginning. 5) The speed matters; too fast tends to draw the chuck out of the taper. Start at about 1/3 speed and increase it a bit as you can. 6) Use lubricant; regular cutting oil on steel, Aluminum cutting fluid on Al. Good luck. -------------------------- Date: Thu, 30 Oct 2003 10:31:28 -0500 From: "JERRY G" Subject: Re: Re: New Sherline User 3. good. Choosing step drills that remove the material that would contact the "web" reduce the drilling force required. 4. A sharp tap with a small hammer or mallet to seat the taper is very effective, but don't hit the drill chuck jaws. Retract them first. Point of Information (Pun Intended) A drill is not a finishing tool for holes. Reamers are to some extent. The most accurate hole finishing is to use a single point boring tool. This will not follow the previous hole but will correct the geometry and can be used to achieve any size. Regards, Jerry G (Glickstein) ------------------------------ Date: Thu, 30 Oct 2003 15:23:16 -0000 From: "w1vt" Subject: Re: New Sherline User I had a similar drilling problem--I wanted to make a 0.55 inch hole in a 1.20 inch outer diameter balsa dowel, 2 inches long. Ideally, it fits snugly over a 0.54 inch paper tube. I put a 1/2" brad point drill bit in a 3/8" tool holder. I was going to use a Forstner drill, but the 5/32" shaft was too big for the Sherline drill chuck. I mounted the tool holder on the cross-slide and aligned it visually with the center of a 1.5" square balsa block--then drilled the hole. It popped out of the 4 jaw chuck twice, but I managed to drill a pretty good hole, almost 4 inches long. I then offset the cross- slide about 20 mils to enlarge the hole. I managed to enlarge about an inch of the hole. To complete the hole, I used a rubber mallet to drive a 0.55 OD arbor I machined out of aluminum down the hole. Remember, this is balsa, not steel. I then mounted the arbor in a 3 jaw chuck and turned the 1.20" OD. Not the most elegant machining job, but I got exactly the part I wanted :-). Zack Lau W1VT -------------------------- Date: Thu, 30 Oct 2003 15:53:04 -0000 From: "Glen Reeser" Subject: Re: New Sherline User Sometimes even when you have done all of this right, the drill bit will still wander. If you put the tool post up against the bit near where it enters the hole you are drilling, it will minimize this. You may want to do this with a tool instead of the post itself to keep from scratching the post. I found a 3/8" Jacobs type chuck that screwed onto my 0 morse taper tailstock mount. This lets you chuck large bits with a reduced shank. Glen Reeser -------------------------- Date: Thu, 30 Oct 2003 16:00:52 -0000 From: "texas_hoppy" Subject: Drilling Problem Help I have been thinking about this problem since I posted my help message yesterday. All of your answers helped put it together in my mind. I will try it this weekend. What would some of us do without groups like this or the internet? Thanks Again, Larry Reese Kenney, TX www.shadygrovefarm.com ---------------------------------------------- Date: Mon, 17 Nov 2003 15:08:32 -0600 From: "Nance, Tom" Subject: RE: Need help on picking out drill bit set [SHORTER SET FOR SMALL MACHINES LIKE SHERLINE/TAIG] Hi Rick, Short length drill bits are called either "Screw Machine Length" or "Stub-Length" drill bits. MSC has a large selection of Screw machine length drills. Their set of 1/16 to 3/8" by 1/64" bits (from Cleveland Twist Drills) is part # 08372385 and costs $58.48. That may work for you. On the other hand, buying the 13 bits (1/16 to 1/4" Cleveland bits) separately from MSC costs about $20.00. Go figure. You can also buy the 13 bits as an import for about $8.00. Don't know about ENCO. I like Cleveland and Precision Twist Drill as manufacturers. I like Hanson and Greenfield for taps and dies. Tom Nance Corpus Cristi, TX --------------------------------- Date: Fri, 28 Nov 2003 03:58:30 -0000 From: "mc_n_g" Subject: Re: Cobalt USA-Made screw machine drills - worth it? "Jason Spangle" wrote: > I'm getting ready to dive into some tool & die work on a very small > scale, and was wanting to know if going with a cobalt material for > screw machine length drill bits would be a good idea? > I can get a 1-60 set for $60.00 new in the USA from Enco, I don't > think the price is bad.135 degree split point is how they are designed. > anyone use these? > I feel the shorter length will help with accuracy, less flexing. My father-in-law has a shop I work in on the side(I have a regular fulltime job). We have always used whatever we could get a good deal on. Sometimes it was definitely not worth it. When it comes to drill bits, depending upon what your use, how often, and what you are cutting, I would recommend bright finish or black and bronze finish for drilling. I regularly work with aluminum (7075, 2024, 6061) and steel (tool, O1, cold rolled, hot rolled, etc.) for plastic injection dies and rubber compression dies. There is a definite difference between good quality HSS drills and bargains. Drill bits is where for the most part you get what you pay for. I do not want to sound preachy on this. A lot depends upon your use and cutting fluids (a must). You may want to try a few bits first to try them out before buying a set. Just buy some regular sizes you use and try them before getting the whole set. I have USA made and imports. The USA made last longer and maintain edge longer. They also cost a fortune. Budgets are sometimes tight and you go with what you can get. Get a set and augment it with packs of 10 for drilling tap holes, critical holes, etc. Hope this helps. mc_n_g -------------------------------- Date: Fri, 28 Nov 2003 05:14:36 -0000 From: "Silicon Knight" Subject: Re: Cobalt USA-Made screw machine drills - worth it? A while ago I decided to bite the bullet and invest in good drill bits. I'm using TiN coated screw machine (ie, production length) bits that I buy locally from an industrial supply store. I only buy the sizes that I need when a project calls for it, and for standard sizes I stock up on 3 or 4. Not only is the shorter bit easy to handle on a limited sized mill (I own a Taig personally in my garage, my lab uses a Sherline), but it cuts down on chattering and cuts easier too. On a big machine you can just increase pressure to cut with a slightly dull bit, but the RPM range of the DC motor where drilling occurs (ie, lower RPMs) isn't very torquey and a cheap import bit just isn't worth the grief. Yes, I am paying $2.50 -> $4.00 per drill bit, but I havn't dulled one out so far after a year of playing in the shop. -=- Terence ----------------------------- Date: Sun, 14 Dec 2003 21:36:50 -0800 From: "Dave Hylands" Subject: RE: Re: Square holes > Many years ago my dad brought home from his shop an ingenious, yet > simple device they used for drilling square holes. Check out these links for more information on square holes: http://upper.us.edu/faculty/smith/reuleaux.htm http://mathworld.wolfram.com/ReuleauxTriangle.html The second one has a small animation to show you how it works. Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ ---------------------------------- Date: Mon, 15 Dec 2003 13:47:08 -0700 From: lynn.chidesterx~xxxtp.varian.com Subject: Re: So. Cal New Member and Lathe Owner I want to use the lathe to mill ends of (up to 1") max tubing so I can flush mount them in a "t" like fashion, for building frames. I heard its called "fishmouthing" or "Tube Notching." If this is all you want to do, I'd suggest using a tool called an "Ol' Joint-Jigger". I think Harbor Freight sells a copy. The tool holds the tubing at the desired angle, and a hole saw cuts through the tubing. You just need a drill press, and the correct size hole saw. While the tooling makes the job easier, old time aircraft mechanics did the same thing with hacksaws and files. Lynn C. (in SLC, UT) ----------------------------------- Date: Fri, 2 Jan 2004 16:20:56 -0800 From: "Patrick Lee Rooney" Subject: Drilling holes Is there a standard procedure for the incremental changes when drilling out a large hole with twist bits? I tend to just jump up a few sizes at a time until the desired diameter is reached. Not very efficient with my time, and I spend way too much time grinding bits. If there is some established procedure, I would sure like to be educated. P.S. If your punch press is rated at a certain capacity, and you try and punch holes in thicker than rated stock, you will break your machine! -------------------- Date: Fri, 2 Jan 2004 19:25:55 -0500 From: " Rigrac" Subject: Re: Drilling holes Patrick: A little more info req'd. Hole finishing size, and what type of equipment you are performing this function on would be good to start. Ron -------------------- Date: Fri, 2 Jan 2004 17:17:14 -0800 From: "Patrick Lee Rooney" Subject: RE: Drilling holes Hey Ron....we are building racks and shelving for the new shop. I got a quote from a guy that specializes in shelving and pallet racks, and the cost was really out of sight. I keep thinking I am immune to "sticker shock" at this point, but I never am. Thus, building shelving and racks out of 1/8" and 1/4" angle, 3" channel beams, and 3/4" plywood. I have an "older" punch press rated with the die set for 1/8" max. Punched holes every 6" in the 1/8" uprights with no problems. Then tried punching the 1/4" angle and broke the press. I now have a bunch (100's) of 1/2" holes to drill in 1/4" angle with a single Rockwell drill press. I have spent all day grinding bits, and I just want to be as efficient as possible. I am tempted to weld the beams to the uprights, but know I will regret it down the road when I need to adjust the spacing of the shelves. How would you pro's do it? Thanks for the quick reply. Patrick. ------------------- Date: Fri, 2 Jan 2004 20:33:37 -0500 From: " Rigrac" Subject: Re: Drilling holes Patrick: Unless Rockwell Drill is of the very small bench top variety you should be able to go 1/2 " with one drill no problem. If that is too much for machine and I think you are finding successive drills "grab" and you loose your edge then try to grind a small relief along "land of drill". By "land" I mean look at point of drill from straight on where you can see included angle of drill grind straight in front of you and can see one flute full at the top and disappearing as it goes down away from you. By small I would say 1/64 to a max of 1/32 flat ground along that edge from center out to edge of drill. This will stop drill from grabbing although it might "chatter" a bit. This chatter will not affect drill hole size although is does feel a little uncomfortable on hands. This process is also what you would do to a drill when drilling brass which will grab VERY easily with a regularly ground drillbit. Try it out and let me know how it works. First try 1/2 hole in one shot though. Not too much speed. Ron ------------------- Date: Fri, 2 Jan 2004 17:45:57 -0800 From: "Steve B." Subject: Re: Drilling holes > Not too much speed. less than 300rpm and use some sort of coolant....cutting oil at least. -------------------- Date: Fri, 2 Jan 2004 18:16:22 -0800 From: "Patrick Lee Rooney" Subject: RE: Drilling holes Ron. Do you mean 1/2" in one shot without ANY pilot hole? And yes, successive drills "grab" no matter how much I flood with coolant. I thought I was jumping up in bit size too quickly. The drill press is a large industrial floor model, and can be slowed down to a crawl. I think we were pushing the speed also. I will try the "one shot" approach first thing in the morning (with a fresh attitude). Pat -------------------- Date: Fri, 2 Jan 2004 21:28:59 -0500 From: "piggy" Subject: Re: Drilling holes put in a 1/2 inch drill and crank it up to about 800 rpm and drill the hole. i drilled 400 holes yesterday with a 13/16 bit and no pilot hole , i use a lagun vert mill and drill holes all day every day...... i run a 1 1/4 bit at 400 rpm ,,,,,,,,, a 1/2 at 1000 or so and i only cool with a squirt bottle with coolant and water in it . this is a production shop i work at part time Don T. EVO Power & Machine www.accessatc.net/~piggy www.snartracing.com -------------------- Date: Fri, 2 Jan 2004 21:56:10 -0500 From: " Rigrac" Subject: Re: Drilling holes Patrick: That right! I drill 1/2" one shot with a little bench mounted drill press. If you have a center drill (like what you would use on a lathe) you might want to center first. Ron ---------------------- Date: Fri, 02 Jan 2004 23:18:20 -0600 From: Jon Elson Subject: Re: Drilling holes If you have a LOT of holes to drill, and this sounds like you do, get several cobalt drills with split points. These cost only a few cents more than plain HSS, but will WHIZZ through moderately tough material. The cobalt HSS tools are as easy to sharpen as HSS, but can withstand heavy cutting MUCH better than plain HSS. Don't bother with TiN coating, as it will not be there after a regrind. Jon ------------------- Date: Sat, 3 Jan 2004 04:52:27 -0500 From: Charles Gallo Subject: Re: Drilling holes > Don't bother with TiN coating, as it will not be there after a > regrind. Jon Jon, Actually, the IMPORTANT place for the TiN coating to be is NOT at the point (which, as you say, goes away after regrind), but on the flute, just in BACK of the cutting edge, and that IS still there "post regrind" - sort of. You see, the chips will have been wearing at it, so it's now thinner than it was from the factor, so you will NOT get as MUCH service from the bit until the NEXT grind. At least this is how it was explained to me by the guys from Ghuring Drills. BTW Most of the "inexpensive" TiN coated bits sets you see are JUNK that has been TiN coated to make them pretty. TiN coated JUNK, is well, JUNK. Stick with name brand drills. For some reason, I like C/L and Ghuring. Although NOT appropriate for the shelf job, for deep holes, I've come to really like a parabolic flute. Makes the bit a little weaker in side loads, but then again, you're NOT supposed to be side loading your bits, right? Charlie -------------------- Date: Sat, 3 Jan 2004 00:07:53 -0600 From: "jerdal" Subject: Re: Drilling holes > Is there a standard procedure for the incremental changes when drilling out > a large hole with twist bits? I tend to just jump up a few sizes at a time > until the desired diameter is reached. Not very efficient with my time, and > I spend way too much time grinding bits. If there is some established > procedure, I would sure like to be educated. Yes there is. If you need a pilot hole, you make it the size of the 'web" in the center of the final drill. Then drill your pilots, and go right to final size. You can do two steps if you make each the size of the web of the next. Nice in production to drill pilots precisely and then just burn thru on another DP with final size. If you have to change drills it's a pain. If you can get away with direct final size, go for it. works best with power down feed, but will work. Problem is the excessive force due to the point scraping and not cutting at the web area. that's the good thing about pilot holes. But split points help fix that. Still takes feed pressure, which is why power feed is nice. If you try to increment up, you chip drills as you start the hole with the next size, and it takes way too long anyway. Speed? Faster. Clamp the work and speed up. A 1/2 inch drill has 1.5 inches hole circumference. So each 8 RPM is a foot per minute. Thus, with a 1/2 inch drill, for a very minimal cutting speed of 40 FPM, you need to go at 320 RPM. Since 80 FPM is more reasonable for HSS and mild steel, 640 RPM is still reasonable for a 1/2 inch drill. Smaller go faster. And in production, wear out drills but get it done faster. Drills are usually cheaper than time, and they can be sharpened. Jerrold ---------------------- Date: Sat, 03 Jan 2004 09:14:13 -0600 From: xlch58x~xxswbell.net Subject: Re: Drilling holes Agree Cobalt will do an exceptional job, but have to disagree with the remarks on TiN coating. The TiN coating is still on the cutting edge after a regrind if you are grinding your drills correctly. The front face of the Flute is what is cutting, what you are grinding is the face of the tip, or the clearance angle. Regarding the original posters question about stepping up in drill sizes, only two drill are really needed and one if you use a splitpoint drill as Jon has suggested. The reason for stepping up in drills other than accuracy (not an issue in this case) is to account for the small area of a standard drill that doesn't cut. If you look at the tip of a standard ground drill bit, you will see that the cutting edges do not meet at the point, instead, there is a small pointed area. During drilling, this area just wears its way through the metal and creates heat. You need to select a pilot drill that is larger in diameter than the width of this non cutting area on you final drill. The pilot drill should be as small as possible so that the non cutting area on it is as small as possible. 135 degree split point drill solves the problem by making the cutting edges meet in the middle. Nifty solution, but they will not track a punch mark as well. Charles ------------------------------ Date: Tue, 17 Feb 2004 23:29:20 -0600 From: "jwalters" Subject: Re: Drill Bit Recommendations? Brass. Aluminum and Steel each work best with a different type of drill bit. Brass cuts best with a drill with a modified cutting edge, a small neutral angle flat ground on the cutting edge. Most grades of brass do not cut good with a sharp edge, a sharp edge causes the drill to bite into the material creating chatter. Black oxide bits work best on steel and shiny bits are best for aluminum. Cobalt bits are generally high quality and expensive and are intended for harder grades of steel, with a TIN coating cobalt bits are good for most materials. Hard brass still works best with a neutral flat on the cutting edge. Cast Iron cuts best with a black oxide bit or expensive carbide grades. In a production environment, solid carbide or carbide inserted drills with grades optimized for an application are used. In reality a home shop machinist can drill most materials with whatever drill is available. Just to through in an additional style, parabolic flute drills are best for drilling deep holes. Letter drills are frequently needed to optimize tap drill hole size to optimize thread fit. I hope this helps. John Walters ------------------------------- Date: Wed, 03 Mar 2004 12:47:14 -0500 From: RichD Subject: Re: Spotting drills? A good spotting drill (some are just very short drills) has no pilot tip like a center drill has and comes to a very small point. That is, the chisel tip as found on drills is extremly small. This is the correct type of tool to use for "spotting holes" for accurate part layout used in conjunction with x - y movement and a DRO or CNC. The basis for its use is to provide a rigid accurate starting point to help control the starting of the following drill procedure. A center drill will also "spot holes" but takes considerably longer and there is the habit of the tip breaking off in the work. Use these tools with cutting oil. The pilot tip of a center drill can be used for a spot drill and works well for a lot of cases, but the chisel point is the same as a normal drill. For small holes to drill, a very small center drill would have to be used or you find the drill wandering on the flat bottom left by the center drill tip. For larger drills, it's better to drill deeper to "spot" with the 60 deg cone part of the center drill. That takes more time and a lot of material has to be removed burying the pilot tip and if not careful, choking it, resulting in a broken tip buried in the work. Be careful, retract often. Spot drills have the same included angle as a drill point with very small tip geometry. A much better matched depression is left for the drill to follow and you can chose a depth you need to suit the drill diameter. I use a 1/4" spot drill exclusively for all sizes down to #60 drill. The center drill tip is to give clearance for the actual lathe center tip. It's not a good idea to have a lathe center bearing on its very tip. Down the shank a bit spreads the load out giving a larger bearing area. Yep, some lube in the hole will help as well. RichD -------------- Date: Fri, 19 Mar 2004 22:21:41 -0000 From: "tsterling2000" Subject: Short, stiff small diameter drill bits My wife makes small art baskets and uses my Sherline equipment to make rims and bases for them. We've recently run into problems drilling small diameter holes (in wood) without the bits wandering. Does anyone know of a source for short, stiff small diameter (under 1/8 inch) bits in graduated sizes? Regular (as in hardware store) bits aren't stiff enough and easily wander half a diameter off in very short distances. Who would have thought it was harder to drill good holes in black walnut than in steel? If you'd like to see what I'm talking about, visit our web site at http://www2.whidbey.net/netsuke/ and click on the Containers for the Soul Art Baskets link. Thanks in advance. Tom Sterling ---------- Date: Fri, 19 Mar 2004 17:42:02 -0500 From: RichD Subject: Re: Short, stiff small diameter drill bits I would suggest PCB carbide drills, but you will have to see if the typical short flute lengths will do. The shanks are all 1/8" dia. Also, in small sizes, anything tending to defect them will snap them off. OTOH, I use a No. 38 to drill down the side (partially into) of alum. heatsink fins by the 100's with no problems. CNC controlled. RichD ---------- Date: Fri, 19 Mar 2004 18:01:05 -0500 From: "Jerry Glickstein" Subject: Re: Short, stiff small diameter drill bits Go to MSC Direct, (Google) and the items you want are "screw machine length twist drills". There are many manufacturers. Always centerdrill first to start the hole where you want it. #00 have .025" pilot drill diameter with a .125" shank. I have also reduced the pilot diameter by grinding the OD. Regards, Jerry G (Glickstein) ---------- Date: Fri, 19 Mar 2004 23:52:37 -0000 From: "n2562001" Subject: Re: Short, stiff small diameter drill bits I have had this problem for years. Drills tend to follow the grain of most woods. The best solution I have found is a center cutting end mill at high speed if they are the right size and long enough. The second best is a sharp standard twist drill held in a WW collet with only the depth of the hole exposed at the highest possible speed. Jerry Kieffer ---------- Date: Fri, 19 Mar 2004 17:13:34 -0800 (PST) From: Henry Flymo Subject: Re: Short, stiff small diameter drill bits Something you could do is grind a simple spade drill. Use drill rod that is what ever size hole you want and grinde it flat 1/2" up on both sides evenly to the thickness of the end of a screw driver. In fact it will look like a screw driver. Next grind it the other way to make it into a centered point 80 to100 degrees included angle. And last put 5 degrees relief angle on each flute and make sure angle is leaving leading edge for right hand revolutions. ---------- Date: Fri, 19 Mar 2004 19:19:06 -0800 From: "David" Subject: Re: Short, stiff small diameter drill bits Is there a good reason that you're not prick-punching and center-drilling before you drill? Dave Wood ---------- Date: Fri, 19 Mar 2004 22:50:43 -0500 From: "Jerry Glickstein" Subject: Re: Short, stiff small diameter drill bits Dave, offhand, I would avoid prick punching in wood. Violent and upsets the fibers..... Regards, Jerry G ---------- Date: Sat, 20 Mar 2004 04:50:56 -0000 From: "n2562001" Subject: Re: Short, stiff small diameter drill bits Jerry, I don`t think center drilling wood will resolve Tom`s problem. At least it has never stopped small drills from following the grain when I have center drilled first. Jerry Kieffer ---------- Date: Fri, 19 Mar 2004 19:26:27 -0800 From: "Marcus and Eva" Subject: Re: Re: Short, stiff small diameter drill bits One of the best ways to keep a drill from wandering in wood, is to modify the point to a brad point with a peripheral scoring chisel on each flute. Look at woodworking bits like Forstner bits to get an idea of the desired geometry. This shape can be a bit of a challenge to produce in a tiny drill, but with a clever setup in the mill or the lathe it can be done. The problem with wood is that it has both hard and soft grain strata that lie adjacent to each other. So even if the drill is sharp and started correctly in a center drilled hole it will wander as soon as it hits a hard stratum only on one side. Putting the Forstner bit geometry on the tip, alleviates this somewhat by removing the wedging effect produced by a cone pointed twist drill. It will be self guiding because of the two scoring chisels on the periphery, and the flat bottom tends to minimise side forces caused by uneven hardness of the wood. In fact, the principle is similar to that which Jerry Kieffer exploits when he uses an endmill. The flat bottom minimizes wander (as does the stubby length). Cheers Marcus ---------- Date: Fri, 19 Mar 2004 22:48:42 -0500 From: "Jerry Glickstein" Subject: Re: Re: Short, stiff small diameter drill bits Marcus, you have put your finger on the problem. The material to be drilled is part of the system. However, another solution occurs to me depending on the application. It is a cheat, of sorts, but it will work. Centerdrill, drill and bore for larger plugs that are drilled out in the lathe, and then pressed and/or glued in place. Single point boring (for the plug) is the really accurate way to prevent wander, bad geometry, etc. There is ALWAYS another way. :) The tip modification (chisel points)is almost impossible in really small drills. Regards, Jerry G (Glickstein) --------- Date: Sat, 20 Mar 2004 15:10:51 -0000 From: "n2562001" Subject: Re: Short, stiff small diameter drill bits Jerry, what I am referring to is drilling with both the mill and lathe. I always center drill but only to position the tip of the drill as you would do in metal. Small drills will almost always follow the grain unless held very short and ran at very high speed. My big headache machining small handles for scale tools and then trying to drill a hole down the center for mounting. I no longer even try since it is faster to drill a hole in oversize stock and put it on a mandrel for turning. If you put a piece of hard wood in your lathe and try to drill a small hole through it, it won`t take you long to figure out what I am referring to. (Unless you get really lucky) Jerry Kieffer -------- Date: Sat, 20 Mar 2004 07:47:57 -0800 From: "Marcus and Eva" Subject: Re: Re: Short, stiff small diameter drill bits Hi Jerry: Have you ever tried brad point drills? Not perfect, but quite a bit better than conventional metalworking twist drills. I grind the points on the tool and cutter grinder on the rare occasions where I need one, but I'm sure a stoning jig with roller followers (bit like a filing jig for the lathe) could easily be made up for tiny drills, and those with no cutter grinder handy. Cheers Marcus -------- Date: Sat, 20 Mar 2004 16:27:17 -0000 From: "n2562001" Subject: Re: Short, stiff small diameter drill bits Marcus, I think I have tried just about every kind of point including various spade drill modifications. While some points work quite well with larger drills, nothing seems to work with drills under about .100". It seems that the hole will be no straighter than the grain of the wood. Jerry Kieffer -------- Date: Sat, 20 Mar 2004 09:59:34 -0800 (PST) From: Scott Meyer Subject: Re: Short, stiff small diameter drill bits Interesting. I have worked in a few tool rooms, die shops etc. I have never done both prick punch and center drill. If I prick punch, I'll put a small drill in the chuck on the drill press and move the vise until the drill doesnt flex into the punch crater. Change drill to the proper size and drill. If I need an accurately located hole, I'll put it on the mill and use an edge finder (usually) to locate the hole, and then center drill it. One thing that I was taught, is that prick punching isn't very accurate. The width of the scribed line, the parallax error from being unable to look straight down where the punch is pointing, the relatively broad point of the punch, etc. Just seems to me the more operations you do to drill a hole, the more inaccurate you are. Tolerance stacking - ie error in layout, added to error in punching, added to error in centerdrilling, added to error in drilling, makes a pretty big margin for error. I try to centerdrill everything. If I use a transfer punch or something, I'll use a pointer to locate the hole if I need any accuracy. A center drill is stiff, and doesn't flex like a drill will. Just a comment about the included angle of the points involved (the punch and drills, not the discussion points). A typical drill has a 135deg point. I dont know what a typical prick punch angle is, but it only lasts until someone sharpens the point on a grinder. I have never ever heard of anyone setting up a cutter grinder or something to maintain the angle on the prick punch. They take it to a pedestal grinder and offhand make it pointy again. The centerdrill has 2 angles, a 135 deg point, and a 60 deg. When I centerdrill, I only use the 135 point, which matches the drill point. If I drilled into the 60 deg, I would only be locating off a small ring, and not a larger surface. Has always worked for me, not saying other ways don't work. Scott ---------- Date: Sat, 20 Mar 2004 13:14:12 -0500 From: Stephen Brown Subject: Re: Short, stiff small diameter drill bits I prefer brad point bits for accurate hole drilling in wood. Lee Valley sells good HSS bits down to 5/64". You can get stub length ("screw machine") twist drill bits from any good tool supplier (e.g. MSC, McMaster-Carr, Enco, &c.) but I think you'll still have trouble drilling straight holes, I think. You need a point geometry that doesn't get deflected by the wood grain. Lee Valley re-grinds their brad point bits from regular jobbers length twist drills, so they're regular length, but you could always cut down the shank or bury most of it in a collet or custom holder. But I think you'll find good brad points bits will do what you want. Steve Brown --------- Date: Sun, 21 Mar 2004 23:17:01 -0800 From: "Marcus and Eva" Subject: Re: Re: Short, stiff small diameter drill bits > The largest we've used sop far is about 3/32 inches, and we go > considerably smaller than that. 3/32 isn't too bad about wandering, > but smaller sizes are. We've had some luck with a few odd looking > carbide bits I came across in a one time surplus sale. Tom Sterling The carbide drills you found were probably circuit board drills. They are intrinsically stiff, being made of carbide, but some brands have such deep flutes ground in them that they become quite flimsy and will break very easily. Most of the major tool suppliers stock them; I've bought them from KBC in the past. You may be better off with carbide spotting drills; I'm not sure though, whether you can get them easily in small sizes. The brad point style is still superior for woodworking if you can find or make them. The faster you can spin them the better too. You'll need to peck drill; don't try to go all the way through in one shot, unless your hole is no deeper than 1 1/2 times the hole diameter. If you're doing this on a Sherline mill, you should get the 10,000 RPM pulley, and the sensitive drilling attachment; it will make your life MUCH easier. If you're well off financially, it would be very worthwhile to purchase the Sherline CNC rotary table too, or join the CAD CAM EDM DRO list and learn how to make your own from the existing turntable you already are using. It's not difficult, and it's much less expensive than buying the Sherline version, but the Sherline is a good unit for this application and has some nice features. If you're doing this a lot, and your work is commercial (and can justify the expense), you might need to invest in the means to be able to repoint your own drills too...it's not difficult once you have the tools, and have learned how to do it. A diamond cup wheel and a moderately ingenious fixture will set you up nicely to do it on the mill. Cheers Marcus ---------- Date: Tue, 30 Mar 2004 15:01:57 EST From: toolroomtrusteex~xxaol.com Subject: Hole saws for drilling [Metal_Shapers] dreilanderecht wrote: //Are you onto the technique of using hole saws? The decent HSS ones, not the cheapies from the hardware store. These can be used to make a hole, they can usually go in about 1.5 inches, so going from each end you can get a hole through a three inch thickness of metal, and you get a potentially useful round piece from inside. You can also use them the other way around, eg put it in from the end and then a parting tool from the side to take a ring off. You naturally need to put a boring tool through afterwards when you are making a hole, but it can save a lot of time.// John: That's a great idea! I assume you'd still have a hole in the center of the hole sawed out plug from the pilot drill but that wouldn't necessarily be a problem. Larry --------- Date: Tue, 30 Mar 2004 14:27:19 -0600 From: "Brian Alley" Subject: Re: Hole saws for drilling When I do this i do not use the pilot drill. Either run the hole saw in the tailstock or mill head and I find it sturdy enough to do the job. brian. -------- Date: Wed, 31 Mar 2004 02:24:20 -0000 From: "dreilanderecht" Subject: Re: Hole saws for drilling As Brian says, you don't always need the pilot drill...I tend to leave it in if I have no specific use pla