------------------------------------------------------------------ This is just one of some 80 files about machining and metalworking and useful workshop subjects that can be read at: http://www.janellestudio.com/metal/index.html ------------------------------------------------------------------ BROACHING could be simply defined as forcing one object through a smaller hole in another object, to make the hole bigger or change its shape or change its interior surface in some way. The most common broaching procedure used by machinists is to cut a keyway slot inside an already round hole so that the object (examples: gears, knobs, etc.) can then be fixed onto a shaft. Keyways in professional shops are cut most often using an arbor press, that drives a stepped, toothed cutter through and makes the slot. While the presses are relatively inexpensive, a good selection of cutters will be costly. Consequently home shop machinists sometimes try to use their lathe carriage (LATHE OFF AND UNPLUGGED!!!) to push a cutter device through the part-with-a-hole that is being held firmly in the chuck or on a faceplate, with the lathe spindle solidly locked against rotation. Unfortunately the forces involved can be extremely high if too big a bite is attempted, and carriage parts have been damaged all too frequently (any savings are gone in a second, not to mention time and effort to get/make new parts for the lathe). Then there is broaching without cutting, where a male form is forced through an existing hole in a malleable object. A typical use would be to force a rod of square cross-section through a round hole, to make interior corners that would then grip the square shank of a handle. Significant preheating of the part with a round hole is needed for steel. Obviously, this procedure will not work with brittle materials that will crack. It works badly with elastic materials that will return to near original size and shape. The process may distort the exterior of the target object; material is displaced, not removed, so the object gets bigger or misshapen somewhere. Broaching processes warrant careful study in reference technical books or equipment manuals before risking a rare or expensive part. While the processes look simple, skill and finesse to do them well can only be acquired through research and patient practice. And for the lucky few that actually read this file, there is an off-topic conversation that started about broaching and veered hard about -- but the subject will be well appreciated by any machinist. Not surprisingly, it comes out of that happy band in the Metal_Shapers group. Even if you don't have a shaper (yet), you might want to read that group's stuff -- by far the most entertaining and for that matter educational. I'm just sorry that so many of their off-shaper-topic threads do not fit into my particular subject files. 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 many additional files on my home page Machining and Metalworking at Home http://www.janellestudio.com/metal/index.html 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 - 2015 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: Thu, 30 Nov 2000 01:18:26 -0000 From: ikimjingx~xxyahoo.com Subject: Re: Broaching key slot In atlas_craftsmanx~xxegroups.com, "Skip Evans" wrote: > I need an education. I have seen broaching accessories but never a > broaching machine. I am about to built a crossfeed handle and > need to broach a key slot so it will go onto the shaft. I've > heard something about broach bushings but have not seen any. > HELP!!!! skip Hi Skip. The bushings for broaching fit in the bore of what ever you are cutting. They should be a slip fit to work best. The bushing has a slot milled in it lengthwise_and its size will be a couple of thous. wider than the width of the broach. This is to guide it and support it as you push it thru. After the first pass thru then you place shims between the broach and the bushing which causes the next pass to cut a little deeper into pc. You continue to req. depth. Hope this makes sense. ------- Date: Wed, 29 Nov 2000 18:15:00 -0700 From: lynn.chidesterx~xxxtp.varian.com Subject: Re: Broaching key slot For keyway broaches, the bushings are either collared/flanges or plain. The plain type is a cylinder, with a slot cut (on axis, lengthwise) sized to contain the broach during the cutting action (typically in an arbor or hydraulic press). The collared/flanged type are the same, except with a larger collar to keep the bushing from being pushed through during the broaching operation. The depth of cut is controlled by how far the broach is pressed into the work,, adding shim(s), and repeating (if needed). Most good tooling catalogs show these. They are also (with access to a mill to cut the slot) an easy lathe project. Check the MSC 2000/2001 catalog pgs 603-4 for some pictures. Enco also has them. Lynn C. ------- Date: Fri, 01 Dec 2000 03:41:13 -0000 From: "howard yoshida" Subject: Re: Broaching In atlas_craftsmanx~xxegroups.com, "Carl Carlsen" > Perhaps this was already mentioned? Broaches are expensive, > especially those "other than" the Taiwan kind. Depending on > your frequency for broaching, if you have access to a mill with a > "hand vertical feed" (like a drill press) you can grind a lathe > tool to the width of the desired keyway. Put this in the spindle > and clamp your material on the table. Raising the spindle up & > down you can make small cuts by hand, feeding a few thousands at > a time and cut your keyway this way. You can use either the X > or the Y axis, depending on how your desires. You might > accomplish the same thing on a good drill press, but you need to > "lock" your quill so it doesn't turn at all. > The same thing can be done on a lathe. Put your wheel or > whatever in your chuck and a similar lathe tool in the > toolholder. You can move the crossfeed into the material by > hand and with a "back n forth" motion accomplish the same thing, > feeding into the keyway with the crossfeed. > Slow, but saves spending the money on a broach. Carl I don't know what you are going to broach but if it is a shaft and maybe a pulley ,put the pulley on the shaft and drill a hole facing the end of the shaft and pulley so the hole would be half on the shaft and half on the pulley and insert a round pin. Thank you, Howard ------- Date: Fri, 1 Dec 2000 11:18:48 -0800 From: "Wally Skyrman" Subject: Cutting keyways There has been numerous post on cutting keyways using a broach. Long before I bought a set of broaches I used my lathe to cut keyways. In essence you will use a boring bar with the cutter bit being turned 90 degrees in the bar and the carriage pushing the cutting bit into your hole of the work that is in the chuck. If you use the hand crank that Atlas provides on the carriage to push the boring bar into the work you will break the little gear that rides on the rack and maybe the pot metal housing that supports the gear. Not pretty trust me. Been there and done that sort of experience. Since the operation works so well I made an attachment that hooks on the tailstock ram and by a lever and push rod takes all the load off the carriage gears. You can make internal keyways easily and pretty fast. By using the dividing head on the headstock you can do splines I suppose. This attachment to make keyways was written up in the March 1981 issue of Skinned Knuckles a car restoration magazine. I can send interested parties 2 Jpegs of the article if you want to build your own. Wally Skyrman Central Point, Oregon ------- Date: Mon, 09 Apr 2001 14:09:37 -0500 From: Jon Elson Subject: Re: WHO MADE THIS 4 JAW... [SQUARE BLIND HOLE AS IN LATHE CHUCK SCREWHEAD] > I will soon have a need to make a blind square hole, and am intrigued > by your allusion to a homemade broach. Would you be kind enough to > describe how you made a square broach and how you use it to make a > square blind hole. This will be very helpful, and thank you very much. I have done this on occasion, too. You drill a hole with a diameter that is just about the width of the flats of the square. You take a square lathe tool blank, and grind down to the size of the square, if needed. Then, relieve the sides a little, so it makes a sort of 'shovel' that will scrape the flats. Depending on the exact size, need for precision of the flats or corners, etc. you can decide to make the cutter shape just one corner at a time, or shape the whole flat with both corners. You put the tool in the lathe so it scrapes the flat closest to you as you back the crossfeed out toward you. What you do is lock the spindle with the index pin, and drive the tool into the hole with the carriage feed wheel. You advance the cutter a few thousandths every cycle. This is essentially a manually powered shaper. Jon ------- Date: Tue, 10 Apr 2001 05:01:07 +0000 From: dana.zimmermanx~xxatt.net Subject: Re: WHO MADE THIS 4 JAW... Disclaimer: I am not an expert, but I was in the presence of one for some years. My father is a retired tool and die maker. I did not take up the trade, having gotten trapped in the computer industry when it was a job instead of a religion. What little I know is more theory than practice, and should be informed with your own skills and experience. Jon's description of the method is clear. I would add this can be an ugly way to treat a good lathe, especially a small one like a 6" Atlas. For the 6" Atlas forget the handwheel, as you would simply destroy the gears, which are zamak (read "pot metal"). Find a way to use the tailstock ram to do the pushing, or better yet, a way to guide the tool and attach it to the ram of an arbor press (they are dirt cheap at harbor freight) and push with a tool made for it. With a big arbor or hydraulic press you could drill a hole slightly over the size-across-flats for your square hole, and some longer than target depth, to accept the swarf which will stay in the bottom of the hole. Make a bushing to guide the tool to the workpiece, with a hole in one end for the workpiece, and a through hole to fit the corners of the tool. Use a HSS tool bit, ground to the finish size and lapped or polished, or preferably a stock piece the right size, then ground flat across the end and honed. Make the tool just long enough to do the job. You do not want to have it flex and break outside the bushing, because the pieces will come and get you. The rest is brute force. Literally putting a square peg into a round hole. There may be better end geometry for the tool than squared off, and it really ought to have relief, but hey, it is not moving fast or far. Much more than a pretty small hole would take a very great deal of push. This is as much cold forming as cutting. Possible for a homemade square socket wrench, or socket bolt, but not much bigger or deeper. I have seen cheap 3/8 drive socket wrenches made this way. You can see how it was done because the displaced metal is still in the bottom of the hole, curled towards the center. Of course that is a hex hole, and it may have been done hot. I referred to another method. I have seen a home made milling cutter, a D-bit, whose end was a cone with an included angle that was exactly tangent to all three sides of a square corner (visualize a half-center poked into the corner of a box) With such a tool one can neatly inside mill square boxes, with little or no fillet in the corners or edges, one corner at a time, four setups per box; if the boxes are wide relative to their depth. I forget the angle of the cone, and have started, once or twice, to derive it. It is a nice little geometry problem. If I ever really need the tool, I'll figure it out. Or you can, and remind me. I think it was about 87.5 degrees or thereabouts. This is probably a chestnut in the die-making trade. This would not work for the chuck screw, because the depth to width ratio of the hole desired leaves no room for the tool. ------- Date: Tue, 10 Apr 2001 02:59:36 -0700 From: S1 Subject: Re: Re: WHO MADE THIS 4 JAW... Actually, if you have access to a milling machine (or drill press) and a bench grinder, you can make a tool which locks in the chuck and cuts the sides out a round hole to make it square. A machinist I knew made a tool that did this out a broken end mill, (a shank from a drill 3/8 to 1/2 ought to work). He just ground the broken end square on a surface grinder with an indexing head until it was the right size. A bench grinder will obviously be less accurate, but it can be ground close enough that it will make a round hole square, (the equivalent of a mortising chisel in woodworking). Just put it into the chuck and use the gearing on the quill like you would use an arbor press. I've used this tool and it works really well for squaring up a round hole. Gabe ------- Date: Tue, 10 Apr 2001 21:45:53 -0500 From: "Dana Zimmerman" Subject: RE: WHO MADE THIS 4 JAW... NO! NO! Not the drill press. I spent a day and a half tearing down the quill of mine and filing the dingle berries off the quill rack after making that error, and I would hate to screw up yours by proxy. The quill is often mild steel, and just won't forgive this kind of abuse. Go with the keyway attachment in the files section, it looks to be a good one and a nice tool to have. This device gets around the objection I mentioned about using a lathe apron drive to push a shaper tool which can screw up a lathe as quickly as a drill press. If you cannot find the files section I will email you the picture, which is a large .bmp (bitmap) file, and on my PC wants to print as 47 by 21 inches, or thereabouts. ------- Date: Fri, 13 Apr 2001 03:39:48 -0000 From: fyunchx~xxaol.com Subject: Re: WHO MADE THIS 4 JAW... My two suggested methods for making the shallow square blind hole: 1. Order the book from Lindsay publications on making your own EDM machine, and build one. Then use it to square up a round hole. Very educational. or, 2. First drill 4 small blind holes (about .06 dia) at the corner locations, then as large a center hole as fits. Then grind out the webs with a Dremel tool. You don't need sharp corners in the hole, because your wrench has rounded edges. W.C. Gates ------- Date: Fri, 21 Sep 2001 13:04:29 -0500 From: jmark.vanscoterx~xxamd.com Subject: RE: Drag a keyway? > What type of lathe did he have? How big are the shafts? Isn't the pinion that pulls the carriage along the rack a zamac cast gear, rather than a steel cut one? I agree that it certainly can be done, and has been done many times. My point was that a big lathe is stronger than the operator, but sometimes an operator is stronger than a small lathe. Just take care and use common sense, then all will be well. Mark V.S. in Austin, TX I have used the drag method on both a 6 inch and 12 inch Atlas. Almost like using a single tooth file, light cuts not to strain anything. Since you are using the rack there is no strain on the lead screw or half nuts (I think which have the weak points on the Atlas.) John Meacham High Desert of California, Palmdale, Littlerock. ------- Date: Fri, 21 Sep 2001 15:35:53 -0500 (CDT) From: dswrx~xxwebtv.net Subject: Re: Drag a keyway? I stripped a tooth off the carriage travel rack, early on, on my 6" Craftsman/Atlas lathe. (back then the item was pretty cheap) I was trying to make a keyway or something (i forget) and the pressure was too great. In one of my metal working books, a method of cutting internal keyways (and it should work for external, as well) on a lathe is described. To prevent the wear and tear on the lathe rack (and the operator), a long (12-18") handle made of flat stock is pivoted at one end on a block mounted in the center of the ways behind the carriage. A link (made of flat stock, 4 or 5" long) is fastened ( pivoted) on one end to the carriage (close to where the threading dial is mounted) and the other end of the link is pivoted on the handle at a point approximating the distance (4 or 5") from the center of the ways to the pivot point on the carriage. By moving the end of the handle back a forth, the action of a shaper can be simulated. (i hope i described this well enough, i know a picture is worth a lot of babble, but i can't draw) 8-) Leo ------- Date: Fri, 21 Sep 2001 14:58:42 -0700 From: Chris Difani Subject: Keyway Cutting and Tools for Doing It [atlas_craftsman group] Fellow Keyway Kutters: Today, after much discussion and one tool description, Jean Claude uploaded two pages from a March 1981 (I think its' 1981...) reprint of an attachment for the lathe, that will provide the means to cut keyways, without damaging racks, or other pieces of the lathe. What was also nice is that Leo has also posted a text description of essentially the same device, identical concept, a little different detail (and no pictures). I am posting this email because I want both Leo and Jean Claude to know that I really appreciate their work in doing this. That the time that they took from their lives to do this for a bunch of rowdy (except for Mert), sometimes tacky (except for Mert) amateur "wannabe" machinists, is genuinely appreciated. And this also goes for Joe Schulte for all the time and effort that he has put in to his puzzles, chess pieces, and spinning tops. I have these plans myself, and as soon as I get my lathe back together, I am going to make the top for my neighbor. It seems like we are always ready to make a negative comment, but for some reason we never think to thank people for the wonderful things that they do for us. And that's my $0.02 Chris Sacramento, CA Between San Francisco and Lake Tahoe in Northern California ------- Date: Fri, 21 Sep 2001 22:29:27 EDT From: Sagebush9x~xxaol.com Subject: Re: Drag a keyway? Just a little anecdote of caution-several years ago I was attempting something like this on my 12" Craftsman (101.28990), I don't remember exactly what, but I remember the sickening snap that turned out to be the Zamak "gearbox" for the carriage travel gears. One mounting "leg" snapped right off, & I wasn't forcing it very hard. I jury-rigged it to await the day when my long-awaited mill arrives, & I will make another one, rather than bite the bullet & order one from Clausing, Haven't even dared to price it. Moral? Don't force it... ------- Date: Sat, 29 Sep 2001 13:33:57 -0400 From: Ronald Thibault Subject: Re: Drag a keyway? >what, but I remember the sickening snap that turned out to be the Zamak >"gearbox" for the carriage travel gears. One mounting "leg" snapped right >off, & I wasn't forcing it very hard. I fixed mine with a piece of brass and epoxy. I wrote it up and posted on my Web site in the Atlas section (address below). Ron Thibault Warrenville, SC USA Builder Miinie #2 Captain R/C Combat Ship USS Arizona http://pages.prodigy.net/thibaultr/ ------- Date: Mon, 02 Jun 2003 22:56:48 -0000 From: "dreilanderecht" Subject: Re: square holes In Metal_Shapersx~xxyahoogroups.com, "al_messer" wrote: > What size hole and how deep? Al Messer > --- In Metal_Shapersx~xxyahoogroups.com, wrote: > > Can anyone offer some guidance on tooling / technique for making a > > round hole square on a shaper. The sort of thing I have in mind is > > the hole in a handle for a square shaft or a hole for a square tool > > bit. Is there some conventional way to do it, or do you just keep > > chewing away with a small square tool until you have 4 nice corners? > > Any ideas apreciated. Ron My usual approach for square holes is to use a device that we call a file. I suspect this is just as fast as nibbling away with the shaper, especially in the smaller sizes. A small cold chisel is not to be despised as a means of roughing out the hole, particularly with larger holes. The commercial approach would be to pull through a broach, but you don't want to know what a broach would cost. regards John ------- Date: Mon, 02 Jun 2003 18:35:36 -0500 From: Doug Chartier Subject: Re: Re: square holes A broach does make a fine looking hole though. I bought a half inch square one a few months ago for a particular job. It paid for itself on that job, and has since made me a few bucks. Not many, but it's paid for and still works very well. It is supposed to be good for 1 3/8" in mild steel. Cost between $125 and $150. It does take some serious pressure to get it through the thicker metals, but if you are making crank handles with a half inch hole in cast iron, it works like a champ. You do not start with a half inch round hole either. Requires a 17/32nd. Doug C. Houston, Tex. ------- Date: Mon, 2 Jun 2003 19:40:08 -0700 From: "larry g" Subject: Re: Re: square holes When I needed a square hole for a crank wrench ~2" deep and closed ended I turned a piece of shafting to ~1" dia. I then drilled the shaft to the 1/2" size I wanted. Put the shaft in the mill and milled a slot in the shaft, squaring up three sides and removing one side of the hole in the middle, to the 2" deep mark. I then fitted a new piece in the open side of the slot and welded it in while holding the inside dimension with a square blank. After welding the new side back in the shaft I turned it again to size. If you do a good weld the process should be undetectable except to the closest examination. lg ------- Date: Mon, 2 Jun 2003 22:42:39 EDT From: n8as1x~xxaol.com Subject: Re: Re: square holes for 1/2 in & under ,simply square the end of a hi speed toolbit & drive it thru a champhered slightly oversize nominally round hole....clearance not necessary ....yeah if ur squeamish ,use an arbor press ...( slower!) ....may work w/ larger , 1/2 in is simply the largest I have done best wishes' docn8as ------- Date: Tue, 03 Jun 2003 01:22:15 -0000 From: "dreilanderecht" Subject: Re: square holes Mario, did you ever see Tubal Cains series in the Model Engineer for "Handmaiden"? He built a moderate size horizontal steam engine (Possibly Stuart but I dunno)using nothing but hand tools. A real tour de force. One that I have no desire to repeat, but on the other hand, when you can't find an easy way to do it with the machines, it is useful to remember that it can all be done without them. regards John ------- Date: Mon, 02 Jun 2003 21:46:03 -0500 From: jrw Subject: Re: Re: square holes Mario I always heard the name for a file was an "Armstrong Milling Machine". Joe W ------- Date: Tue, 03 Jun 2003 03:52:59 -0000 From: "dreilanderecht" Subject: Re: square holes I cheated when I wanted a 3/4 square hole for the big Alba, I bought a 3/4 drive socket and brazed it square end out onto the flat steel arm. I discovered in the process that you have to take the chrome off first if you want the brazing to take, which in retrospect is reasonable. So you can readily buy 3/8, 1/2, and 3/4 inch square holes at your friendly local hardware shop. regards John ------- Date: Tue, 3 Jun 2003 21:37:05 +1000 From: "Ron Jackson" Subject: RE: Re: square holes Thanks for all the square hole ideas. I think I'll go for the file/ chisel maybe followed by the drive a square toolbit through (call it a "one tooth broach"). The square hole in the back of a standard socket never occured to me. By the way, the 2 projects I had in mind are a spanner for the shaper ram position adjustment (around 5/8 or 3/4) and a straight type toolholder for a 1/4" toolbit (since I haven't been able to locate anything except the angled lathe type in my search so far. I suspect the toolholder might have to be a mill it out and braze it up job. One thing that this all brings home is - how good hand tools are when there's nothing else. Thanks, Ron ------- Date: Wed, 05 May 2004 21:56:42 -0000 From: "Tommy Ward" Subject: Re: Interesting item on eBay [Metal_Shapers group] > drill a hole 9/32""......take a 1/4 in lathe bit , grind it square > on the end (no relief necessary) & drive it thru ....or press it if u > like...simple ........a shallow chamfer aids in positioning the broach > best wishes docn8as Doc's right. Blacksmiths have no problem with square holes, but machinists make them difficult. Example; how do you put a 1/2" hole in 1/2 wide stock? Simple. Heat material to a forging temperature and drift a small pilot hole thru. Take another heat on the material and drift to size with a double tapered drift (tapering both ends will prevent drift from getting stuck as its driven thru). Aside from being easy, drifting holes (any shape is possible)involves no material removal, which is handy in thin cross sections, and forces the grain structure of the material to flow around the contour of the hole, rather than cutting across grain like is done when drilling, broaching, filing, etc. That's why blanks for highly stressed parts (such as quality tools, etc.) are forged rather than cast or cut from stock. Serious home machinists really ought to think abut acquiring some basic blacksmithing knowledge. Very helpful in making tools and parts. Also a great excuse to acquire a whole new collection of equipment. TW ------- Date: Thu, 06 May 2004 02:47:23 -0000 From: "dreilanderecht" Subject: Re: Interesting item on eBay In Metal_Shapersx~xxyahoogroups.com, "Tommy Ward" wrote: > Serious home machinists really ought to think abut acquiring some > basic blacksmithing knowledge. The old timers seem to have been more aware than we are now...early editions of the Model Engineer often talk about blacksmithing a tool blank out of carbon steel. Of course, we so often use HSS now, so that is one reason why we are less aware. I did have one moment of realisation recently...I needed to make a 26mm diameter cutter and only had inch silver steel (drill rod) After several days of mulling over the cost of the necessary stok, I took a short length of the inch, heated it up to a nice red heat, laid it on an anvil made from a short length of railway iron, and smacked it a few times with a hammer. Of course, not having the proper blacksmiths tools, I didn't get it the same size all the way along, but I only needed one end the full size to put the cutting teeth on. once I was happy, I heated it up again and then left it buried in dry sand to cool. no problem then machining and filing the cutting teeth, then it hardened up fine. You can't work such a tool as hard as HSS, but for the sort of one off work we usually do that is not really the issue. Next time I do a crankshaft I am going to get a local blacksmith to help forge a suitable blank. The one for my launch engine is cast in SG iron, but a forged one would be better. The hard part is putting in the 90 degree twist. regards John ------- Date: Thu, 6 May 2004 16:21:49 +1200 From: "Phil Sumser" Subject: Re: Forging skills Couldn't agree more! It's surprising what you can do with silver steel (or even good quality steel from the scrap yard as long as it has a fair amount of carbon in it). I have made several tools for cutting Acme threads and odd form cutters, counterbores etc and find it quite adequate as long as you keep the speed down and use cutting fluid. It has been very successful--no need to use HSS for these jobs. I usually anneal any unknown steel by leaving it in the woodburner overnight---don't laugh-- it works a treat as long as you get the metal up to a bright red heat first and let it cool gradually. Most steels will then machine with ease. Rgds Phil Sumser New Zealand (Elliott 10M shaper owner----great little machines!) ------- Date: Thu, 06 May 2004 07:58:27 -0400 From: aragratx~xxnetscape.net Subject: Re: Re: Forging skills We got this way of thinking today, "Well, I could do this or that if I had thus and such tool or machine." What our ancestors had that we seem to lack is ingenuity. They could do something with nothing. We can't seem to do anything with everything. Maybe it is a result of twelve years of public school degradation of the thinking ability. Maybe it is the cause of mass production and having money in our pocket to just go buy it. ("It is cheaper to just buy it, than to make it." How often have you heard that from people who just can't understand your obsession for making things?) Maybe it is the fast food joints, instant coffee and central heating that have gotten us in the habit of being impatient. Maybe it is this caldron of 'expert' and 'professionals' and 'consultants' that have taken over our lives, do all the thinking for us, tell us that we are not qualified to think for ourselves, and caution us as to how dangerous it would be lest we should exercise initiative. The "Don't try this at home." mentality. I think the greatest fear people have is to try something that doesn't work. I used to have that fear. Not sure where it came from, but I suspect it was from playing sports with the siblings in grade school/ high school where if you made a mistake you got called names, or worse. And who wants to be called on in class to answer a question? Somewhere along the line I just came to my senses about how silly it was to be afraid of making a mistake, or trying something that didn't work. First off, there is no one there to see me, usually. And second, even if I try something that doesn't work, I learn something. I have leaned more from things that didn't work then from things that did. Doing nothing is worse than failure. Dan ------- Date: Thu, 6 May 2004 00:37:27 EDT From: n8as1x~xxaol.com Subject: home shop tool making In a message dated 5/5/2004, giolw9r4vh001x~xxsneakemail.com writes: > The old timers seem to have been more aware than we are now...early > editions of the Model Engineer often talk about blacksmithing a tool > blank out of carbon steel. Of course, we so often use HSS now, so > that is one reason why we are less aware. I did have the knowledge that one has the ability to fab near any cutter needed is a tremendous confidence builder...nomatter how badly one errs, the means for correction is w/ in your capability..............now one buys a tool only out of preference ......if time is of the essesnce ,most can be made inside of 2 hours , many in a 1/2 hour..........one of village press books ...wisdom of ------ mclean ( senior moment on first name ) is full of simple tooling projects ..reamers counterbores,cutters etc...fabbed w/ machine or file ...........a 1/2 " piece of O1 drill rod , 3 ft long from enco for under $4 ,will make a dozen or so ...after hardening , u can draw it iin the kitchen oven circa 400 deg.for an hour ....just remember to 1/2 the cutting speed................at one time,(turn of the century) most beginning tools were made as an apprentice & basic forge /heat rx were requisites .........as late as 1950 , the first thing i was required to do in a short lived musical instrument repairing apprenticeship was fab my own dent removal & burnishing tools , also pad replacement tools............ best wishes, docn8as ------- Date: Thu, 06 May 2004 14:14:35 -0000 From: "elperkins2003" Subject: Re: home shop tool making You have hit on something here that has intrigued me for a long time. I have a facination with what colonial gunsmiths were able to turn out with next to nothing in terms of tooling. If you see the rifling machines and reamers they used you would be amazed! Of course most of them were accomplished blacksmiths (and all around good crafsman and mechanics) who knew about the properties of iron and steel. When I see the shops and tools they used everyday, I am a little ashamed about what I turn out with a shop full of machines including lathes, shapers, mills, drill presses, etc. that didn't even exist in those days. I didn't make my machines, but those guys actually started out making their own forges, bellows, rifling benches, and so forth. If they were lucky they were located along a stream where they could get power from home made water wheels (used for milling grain also). Along the same lines, I have a copy of a book written by Ned Roberts (.257 Roberts fame) called "The Caplock Muzzeloading Rife". This is a facinating book written about 1930 that details the manufacturing methods that were a lost art even in those days. Some of the people who were doing this kind of work in the late 19th century were still alive and Ned did a great job of documenting the methods and tooling. He tells about hillbillies in Tennesee that were still makeing caplock rifles in 1930 the way they did before the civil war. Great reading. We should be able to make any tool we want, as long as we have good steel to start with! Some might even be interested to the point of taking iron out of the ground and turning it into blooms for forging into medeival type tools and implements. I have experimented with homemade drill bits on my 100 year old Champion Forge post drill. It's a lot of fun and it is true that it is a boost of confidence to know you can to it, even if you never do. Perk in Cincinnati ------- Date: Thu, 06 May 2004 17:51:22 -0400 From: aragratx~xxnetscape.net Subject: Caplock rifle The book "The Caplock Muzzle Loading Rifle" was apparently reprinted in 1991 by Wolfe publishing co. But is now listed on Amazon.com as out of print. Some one has a used one there for $70. Found that the Foxfire 5 book has information about gun making and about iron making and blacksmithing. It only costs about $12. Might be worth looking into. Someone mentioned Hacker Martin as being one of the gunsmiths. Dan ------- Date: Fri, 7 May 2004 00:20:03 EDT From: n8as1x~xxaol.com Subject: Re: Re: Forging skills In a message dated 5/6/2004, aragratx~xxnetscape.net writes: > We got this way of thinking today, "Well, I could do this or that if I > had thus and such tool or machine." Dan , all points valid !!......multiple factors coalescing, but perhaps the most definitive reasons ARE economic .....being poor is a great motivator ....(.anyone else remember straightening nails picked up on a job site so u cud knock something together? ) .as stated , mass production cost improvements & a higher stndrd of living for the average worker allow the luxury of a buy & discard mentality,rather than fabricate & repair...............very simply ,wages have tremendously increased ,& at the same time prices have seriously dropped .......my 1940 industrial supply catalog lists a skillsaw at $248......before WW2, i went to grade school in the city,a neighborhood of immigrant /1st gen. machinists, carpenters ,toolmakers ,craftsman of all kinds....1/2 the people on the block didnt own cars , nobody had two ( that were running),the trucks were rumble seat coupes w/ a box bed built in after taking the seat out, none newer than 5 years old ,most had iceboxes, no horse trailers, one guy had a boat ( he built it ,brass screw after screw w/ hand tools) ....a LOT of bicycles in the rack at the factories.....everybody "fixed things" ...if u couldnt fix something , one of the neighbors could & did .....it was born of necessity !!..our 1931 nash was painted w/brush & each coat rubbed down by a neighbor, a painter (no such thing as a compressor & spray gun ....economically out of sight ). ..........oh yeah , victor mature & his daddy came around every 2 weeks or so to sharpen knives & scissors , in a red one ton truck filled w/ pulleys ,shafts & stones..... by contrast , fast forward 40 yrs.... after borrowing my sons sorry excuse for a handsaw while framing w/ him one day , i said come over tonight & i will show u how to sharpen it .......he asked , how long will it take? ....20 minutes....his answer was , i can buy a new one for that much time spent!!!!!! ...he was a good carpenter ,but still cant sharpen a saw....& doesent have to since he has been a drug rep. the last 5 years .( once again proving me wrong since i asked him ,what drug co. wud hire a 40 yr old,balding, ex stockbroker,home builder w/no pre med background?) cheap import tooling has only added to my problems......now , when i make a reamer ,cutter ,whatever , i not only have to face the fact that i am cheap, but the additional knowledge that now, this is REALLY " dumb " my fathers consistent answer when i complained abt., not having a tool was, he-- son, any fool can do it w/ the right equipment ; it takes TALENT without ....... well, he was only 1/2 right ....... ....if memory serves , that was 100 yr old john shell (schell?) in neds book & think it was in ky, not tenn. , but havent looked at my copy in 30 + yrs ....lots of good vintage info in there ,but roberts was a writer & teacher...not a gunsmith,nor much of a mechanic,& some of the technical info ,i thot, was slightly suspect ( at least i thot so at the time )... but must admit that a few years ago , i made a 257 roberts imp.reamer & fitted up a couple shilen barels on yugo mauser actions .......... olde tyme square (scrape) reamers were still being used after WW2 to put recess chokes in cut off or muzzle loading shot barrels......in spite of some of the full choke claims , i was not able to recess more choke than modified on the few occaisions that required such choking .... best wishes docn8as ------- Date: Sat, 12 Jun 2004 22:36:15 EDT From: n8as1x~xxaol.com Subject: broaching square hole couple months ago ,i answered a post abt. a sq. hole needed ....stated that i had ground a lathe bit flat on end (no releif /clearance ) , bored a hole 1/32 over size (across flats ), countersunk it to clear edges of square & DRIVEN the now broach thru ., for 1/4 in & 5/16 squareholes .... & that i thot ,i cud do so for 3/8 & 1/2 ........i needed a better chuck wrench for my knuckle buster 19th century 12 in 4 jaw ,& it was time to support the statement..........why they choose .450 for flats escapes me, but my 10 in 4 jaw individual/scroll has same size....anyway, i turned up a piece of shafting ,probably 1045, bored 1/32 o/size,countersunk, & releived the back of the hole after abt. one inch ......rough ground down a 1/2 in lathe bit ,finished on surface grndr to .452..( previous broaches were all hand ground ,so it can be done ,but takes more time being careful not to grind away too much)......20 -30 whacks w/ 16 oz. hammer drove it through .......dead blow /rawhide/rubber didnt ......along the way couple pieces flaked off , but broach is still usable again .........O-1 hardened & drawn way down on tang wud take the beating better..........didnt bother w/my 3 T arbor press...12T /20T makes it easy........broach went thru .010+ off center ( no problem ) ....didnt repetetively remove broach ,burrs , ....just plain beat it thru & it works/looks fine .....wud be easier if burrs removed while broaching.............thot occurred that maybe could have left broach at .500 ,heated stock up to forge heat,& it wud go thru much easier & MAYBE shrink back down to usable ......need to check out the math( better be sure to quickly drive it out or we have a shrink fit ) ..............now to scrounge some 5/8 rod for a handle ..................hope this will be of use to someone........... best wishes docn8as ------- NOTE TO FILE: And in a similar vein, Doc wrote the following message during a discussion about making a radius turning tool that took place in the atlas_craftsman goup. ------- Re: broaching a square hole [atlas_craftsman] Posted by: "n8as1x~xxaol.com" n8as1x~xxaol.com Date: Wed Jan 17, 2007 9:50 pm ((PST)) In a message dated 1/17/2007, tkd_master38x~xxyahoo.com writes: > One more thought, why all the fuss over broaching a square hole? FWIW .....i have broached at least a 1/2 doz sq. holes,the largest being .450 using HS lathe bits ...just grind the end SQUARE ,no relief necessary , drill the hole abt 1/32 over size, chamfer ,& just plain beat the bit thru in one pass,multiple poundings ...heavy hammer 2-3 # ..glasses for bit wants to chip w/ a steel hammer head....for the timid , just drive in abt .125 , drive out & file ,repeat till thru... need to be careful to start plumb in the chamfer... best wishes docn8as PS ..hydraulic press wud make life easier...dont think my 3ton arbor press up to the task......at any rate , i no longer worry over square holes....BTW ..a round hole w/ grub screw holds a sq. bit quite adequately in my shaper tool holder built from drwngs by the lately deceased Art Volz.... it has never moved... ------- Manual shapers [Metal Shapers] Posted by: "arthur.marks" arthur.marksx~xxgmail.com Date: Tue Jan 6, 2009 11:12 pm ((PST)) With the Adept no.1 hand shaper discussion going on here, I thought I might put a link to someone's creation from another list I am on. There was a discussion of making odd profiled holes with a 9x20 lathe. The following link was posted: http://tinyurl.com/9nketh Looks like there are some folks still making hand shapers after all! I thought you guys might enjoy. Best, Arthur ------- NOTE TO FILE: The link mentioned above shows the steps in making one variant of a keyway slotting device to mount on a metal lathe. The slotter does in fact function like a miniature manual metal shaper, and is mainly used in broaching type operations as in cutting the internal slot in a gear. Manual shapers (mainly British) are similar in principle except larger and with their own mechanism (similar to a lathe cross- slide) to move laterally across the work. This idea can be adapted to any size lathe. It could even be mounted to work alongside an X-Y table and serve as a manual shaper for other tasks. ------- Broaching - Update [MyMyford] [But this started in the group myfordlathes] Posted by: "John" johnx~xxstevenson-engineers.co.uk stevenson_engineers Date: Wed Oct 7, 2009 3:15 pm ((PDT)) After the non starting episode with the short piece of Allen key with the offset hole in the bottom something Tony said made more sense and that was to offset the tailstock. So tonight found the tool and the same bar and set it up again but this time with the tailstock offset. As I don't like to mess with these settings I used a boring head with the travel set in the horizontal plane. http://www.stevenson-engineers.co.uk/files/broach1.jpg Started up and it belted this straight in about 8mm then stopped and the ball bearing caught fire again Good conclusions:- It works. It cuts very easily and I reckon even on something like a Myford as when it's cutting there is virtually no pressure,and when it stop, it bloody stops. Bad conclusions:- The tools sticks in the work and has to be held in the vise and rocked out, overall due to the simplicity and speed this is a small price to pay unless you has 1245 gross of Allen screws to do. End result. http://www.stevenson-engineers.co.uk/files/broach2.jpg Bit blurred but shows a clean broach and no spiraling but I feel this has to do with why it stopped. The secret is in the tool, if you look carefully you will see the right side is tapered but the left is straight? When it was ground the sticky table way tipped up with a bit of packing and all sides ground. Now the first three will have the, say 4 degrees taper ? but when the last 3 sides are ground because they are sitting on a taper it will grind them parallel. Three sides need grinding with the packing in, then the tool needs reversing and the packing removed. If you are grinding in a chuck fitting on a T&C grinder this doesn't apply. Looking at the tool the three tapered sides have a mark right on the end but the straight sides have a constant mark equal to the depth of cut. What has happened is it wobbled for as far as it can then stopped dead. One other point, this end hasn't been ground just plunged in with a tipped tool at an angle, the pip doesn't matter because of the pilot hole, in fact it only needs a thin band around the edges to do the cutting. So Myford7's idea does work with just a slight alteration, concentric steady hole in the rear of the tool and offset the tailstock. Full marks to Myford7. John S. ------- Re: Broaching - Update Posted by: "Tony Jeffree" tonyx~xxjeffree.co.uk tonyjeffree Date: Wed Oct 7, 2009 3:20 pm ((PDT)) John - Great result. As you say, makes for a good quick-and-dirty solution for occasional use. Regards, Tony ------- Re: Broaching - Update Posted by: "peter104223" p.neillx~xxbtinternet.com peter104223 Date: Wed Oct 7, 2009 11:22 pm ((PDT)) Nice write-up John, but posted to the wrong Myford group ------- Re: Broaching - Update Posted by: "Tony Jeffree" tonyx~xxjeffree.co.uk tonyjeffree Date: Wed Oct 7, 2009 11:25 pm ((PDT)) Oops... Regards, Tony ------- Re: Broaching - Update Posted by: "Tony Jeffree" tonyx~xxjeffree.co.uk tonyjeffree Date: Wed Oct 7, 2009 11:28 pm ((PDT)) Well if the rest of this group fancies reading the lead-in to John's post, and it has been a very interesting and instructive thread indeed, and completely devoid of irrelevant reminiscence, then they will find it here: http://groups.yahoo.com/group/myfordlathes/ Regards, Tony ------- Re: Broaching - Update Posted by: "peter104223" p.neillx~xxbtinternet.com peter104223 Date: Thu Oct 8, 2009 12:03 am ((PDT)) Completely agree, it's been a fascinating thread so far, and very useful for any model engineer. Peter ------- NOTE TO FILE: 12 Feb 2011. Looking through my files today I noticed a couple had not had anything new since 2009. In the case of the broaching subject, no one in groups I follow has talked about anything new over this time period. So here are some videos on line that you should find interesting. The first three are practical for home shop machinists. Broaching A Keyway In A Pulley using a broach and small arbor press. Very instructive. http://www.youtube.com/watch?v=8tAz5YDFtAs This one details making a jig in a metal lathe for broaching an external keyway in a shaft (lots of good tips): http://www.youtube.com/watch?v=eVgZol6Mfvo&NR=1 Slotter keyway cutter for mini-lathe (or adaptable for any small lathe): http://www.youtube.com/watch?v=NpcKTtYPNKM&NR=1 The next couple of videos involve industrial processes and are included for your interest if you have a few spare minutes. This one shows a CNC machine doing a number of high speed operations, including broaching, to make a part. Very impressive. http://www.youtube.com/watch?v=5AB_etoHesI The second is on the subject of Rotary Broaching. Amazing procedures and results. My only critique would be that someone pointing a flashlight at the work area would have greatly improved the photography. http://www.youtube.com/watch?v=gUEcagEmmZo ------- Using a shaper to broach. [Metal_Shapers] Posted by: "Mike Fresnel" fredjenkinsx~xxearthlink.net Date: Mon Mar 3, 2014 9:16 pm ((PST)) Hello, I'm working on a 1911 style magwell (making frame from a billet) and I believe the usual big shop (as in manufacturer) way to do this is to broach or EDM the thing. Problem with broaching (I've read about) is that it can put deformation level loads on the surrounding structure. I'm working in aluminum on this one. I was wondering if it's practical to use a shaper to carve out the mag well on such a thing. The basic shape is an elongated D so why couldn't I get the frame in place, make a rectangular magwell, then finish it to the D profile on one end with the vertical crank and an obviously shaped cutter? I guess I'm asking if that's the proper approach with a shaper. I also have the same question regarding the magwell on an ar15, which are commonly done by hacking about with an end or EDM. In either case one often has to come at it from both ends and my shaper fantasy (I don't actually have one yet) is that I could set it up and do stem to stern from one end. Thanks, m ------- Re: Using a shaper to broach. Posted by: "William R Meyers" wmrmeyersx~xxsbcglobal.net oldstudentmsgt Date: Tue Mar 4, 2014 2:57 am ((PST)) I think it will work. Glen commented on something he called a "Poke Pole" and we have a drawing of such a thing in files as a shaper tool holder drawing by Art Volz. I am not an expert, either, but Glen is. I have already bought the stuff to make a poke pole of my own. ;) Still do not have the thing running, and should be out of here on my way to work right now! Bill in OKC William R. Meyers, MSgt, USAF(Ret.) Guard your women and children well, Send These Bastards Back to Hell We'll teach them the ways of war, They Won't Come Here Any More Use your shield and use your head, Fight till Every One is Dead Raise the flag up to the sky, How Many of Them Can We Make Die! Heather Alexander, March of Cambredth ------- Re: Using a shaper to broach. Posted by: "Charles Brumbelow" mrb37211x~xxyahoo.com Date: Tue Mar 4, 2014 2:58 am ((PST)) I think that roughing the openings with drill or end mill, then bringing them to size and contour with the shaper using a bit holder such as used for internal keyways would work. The smaller opening for the 1911 would require a smaller bit holder and thus smaller cuts. Charles ------- Re: Using a shaper to broach. Posted by: "Mike Fresnel" fredjenkinsx~xxearthlink.net Date: Wed Mar 5, 2014 4:28 pm ((PST)) Hey, Smaller cuts means smaller depth per cut right? I can still probably make the "tunnel" with full stroke cuts, and hence all from one side, as long as the machine is big enough, and stout enough, yes? Regards, m ps - not asking for a guarantee - just looking to try sane things first. ------- Re: Using a shaper to broach. Posted by: rocky_beechx~xxyahoo.com Date: Wed Mar 5, 2014 4:32 pm ((PST)) Poker Pole?!? What is a poker pole? Does anyone have any video of this kind of operation? I was hard enough for me to make an internal keyway in a small diameter hole so from what you guys are explaining I can't really see it working. Russell ------- Re: Using a shaper to broach. Posted by: "Jim S" mrjschmidtx~xxhotmail.com toolingjim Date: Wed Mar 5, 2014 5:21 pm ((PST)) There were a couple of articles in Precision Shooting (IIRC) a number of years ago on just this subject. They were about shaping the bolt raceways for a bolt action rifle receiver. I think a shaper would work well for cutting a M1911 mag well, as well as one on an AR15, cutting the breechblock mortise for a falling block rifle, the finger grooves on a 45 slide, etc., etc. Some of these jobs will need multiple and/or specially ground cutters, but nothing that can’t be worked out by a careful craftsman. Your .45 mag well would probably need two cutters, maybe three. The key to much of this would be proper fixturing. Just clamping the frame in a vise and hoping for the best would be a recipe for disaster. Jim (Just a guy who likes to build stuff) ------- Re: Using a shaper to broach. Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Wed Mar 5, 2014 5:49 pm ((PST)) best results in interior keyway slotting is cutting UP w/ clapper locked ...this removes the slack which results in dig ins ...ALSO ...if the tool post is replaced by a straight inline boring bar w/ bit on the end, the cantilever problem is resolved....i turn up a bar w/ a shoulder on the end to replace the tool post, it is threaded in front of clapper so a bolt retains it to the clapper ..at the end is the ususal hole for a bit ... works better than the ubiquitous holder hanging down from the tool post. also ...7 inch shapers do not like a cutter wider than 1/8 inch & cuts of no more than a few thou........for larger keyways ..the best is two cutter bits ... one full width w/ the center part ground out to mark out the margins w/ a LITE cut ...this also avoids a layout since when both sides touch, you are there....after cutting to full depth w' the narrow bit, you switch to the correct size, line it up w/ your previous marks & finish ....this avoids getting LOST w/ multiple cuttings of the narrow bit & ending up w/ an oversize slot ....been there, even my HD smith mills 16 inch does not like a bit wider than 1/4 inch for slotting. best wishes doc .....probably the inline bar replacing the tool post is the "poke" ------- Re: Using a shaper to broach. Posted by: wmrmeyersx~xxsbcglobal.net oldstudentmsgt Date: Wed Mar 5, 2014 5:50 pm ((PST)) I believe I said "poke pole" not poker pole. but... Google "how to cut key ways in a shaper" and you should get quite a bit of information including, on the search page I got, 3rd item down, a pdf of a page originally at the home shop machinist bbs http://bbs.homeshopmachinist.net/showthread.php?p=172642 titled either How to cut key ways in a shaper or Cutting key way with a shaper. Good info, with pics that are now missing from the HSM page. Also a shaper video of a keyway cutter (aka "poke pole") and other good info. NOTE: I'm not an expert at this, just learned of it myself a few weeks ago. Find the thread about my finally getting my own shaper after 40+ years, and you'll find Glen's posts and my responses and questions on the subject. Bill in OKC ------- quick ,simple square holes [atlas_craftsman] Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Thu Mar 6, 2014 2:45 pm ((PST)) recently made a 1/2 in sq tool post wrench for 1890 prentice bros 15 inch lathe ...i want to again thank the poster of 2-3 yrs back for this method. i have made handles of 3/4 sq for van norman 7 in, & palmgren 6 in milling vises 9/16 sq for 6 in shaper vise the tool post wrench a chuck key for 8 in knuckle buster 4 jaw external square heads .455 FWIW ....center punch scribe a circle of the sq desired use a square /screber to square the circle center punch the corners so the 3/32 plus or minus drill takes out as much of corner as you need drill the corners FIRST drill out the center 1/64 undersize mill out the circle square..... check for fit takes longer to layout than to mill .. ... hope this makes someone's life easier as it has mine. again thank you for the original post wherever it was & whoever you are best wishes doc PS .... for smaller square holes than, 455, i square the end of lathe bit, drill a hole 1/32 or so over size, chamfer the start & BASH the lathe bit thru w/ repeated blows of 2-3 # hammer (eye protection ..steel on steel) ..drive out, give a quarter turn & BASH thru again takes care of bits not tru square...finish w/a file if needed ...form BOTH sides to avoid a taper. if I had a press larger than a Greenerd #3, MAYBE that wud work. ------- Re: quick ,simple square holes Posted by: "Charles" xlch58x~xxswbell.net Date: Thu Mar 6, 2014 2:55 pm ((PST)) I made mine thirty years or so ago out of a cheap universal joint from a socket set. Punch the pins out of the universal joint and replace the short square section with a eight inch bar filed to fit. Gives you a wrench with a male and female end that can be used as a speed handle. I added a 1/2 inch to 3/8 inch socket wrench adapter and now it works on my three jaw too. Charles ------- Re: quick ,simple square holes Posted by: "Starlight Tool Services Ltd" starlight_toolsx~xxtelus.net Date: Thu Mar 6, 2014 4:07 pm ((PST)) Here is the write up from Rick Spaber on making Square holes http://rick.sparber.org/msh.pdf and the one on making Hexagonal holes http://rick.sparber.org/dhh.pdf Walter ------- Re: quick ,simple square holes Posted by: "Bruce ." freemab222x~xxgmail.com bakmthiscl Date: Sat Mar 8, 2014 6:29 am ((PST)) On Thu, Mar 6, 2014, Charles wrote: > Its even easier to drift one. Charles Do you mean "drift" or "broach"? To my ear, "drift" means: "Get the metal red hot and drive a (square) drift through it." This is a forging operation and changes the outer dimensions of the material -- which may be a good thing. "Broach" means to drive a cutting tool (the broach) through, cold, cutting out the corners. There's an "intermediate" operation in which soft metal or hot steel can be "broached" with a square tool -- like a toolbit (i.e., not a broach, not a drift, just hard square stock, possibly with a sperically (or approximately spherically) hollow-ground end. I've used this to good effect on 6061 aluminum, using a HSS toolbit as the cutter. I think I chimed in at the time that forging OFTEN is a viable alternative to machining. Machinists tend to think of tolerances, etc. Well blacksmiths can get good tolerances too, if they do things right. If you're making a socket wrench, the inner dimensions of the square or hex hole matter, but generally the outer dimensions do not. Forging allows you to keep ALL your steel (by punching rather than drilling), resulting in a proportionately stronger tool. Not to mention that properly forged steel may be inherently stronger than machined steel. I may also have chimed in that chiseling and filing are excellent ways to square up a round hole. I made a "hardy plate" of 1"-thick steel by drilling four ("tangential") corner holes and a 1" center hole (I did not have a 15/16" bit, and fortunately the centers of each side don't matter much for a hardy hole). So far, I'd got rid of most of the steel, but considerable clean-up was necessary. I did most of the clean-up using a cold chisel, then filed to the final size. Slow, but very effective, and NO uncommon or expensive tools or equipment were needed. Bruce NJ ------- Re: quick ,simple square holes Posted by: "Charles" xlch58x~xxswbell.net Date: Sat Mar 8, 2014 2:26 pm ((PST)) I have a selection of broaches and use them for various things when needed. I also have square punches and a punch press as well (your intermediate operation) but nothing is simpler than a simple drift. Heat it, drift it and if need be refine the outside dimension. If you start with the right size round hole you would end up with the same external dimensions. Because I am cheap I often will rough forge things like broaches to shape before machining them. I hate turning expensive steel into shavings because I have found very few uses for shavings. Dad used to till them into our gardenia bed, but as a kid I hated getting those shavings in my barefeet, so that is a non starter. Charles ------- Re: quick ,simple square holes Posted by: "L. Garlinghouse" lhghousex~xxsuddenlink.net Date: Sat Mar 8, 2014 1:50 pm ((PST)) Charles says: "It's even easier to drift one." Which is not exactly the same as what Doc and others were saying. They were cheating and drilling holes first and then banging away. If you have a sturdy enough punch and a big enough hammer, it IS pretty easy and quick. War Story: Sometime in the early '70s I was visiting kin in central Mexico and the after market extractor exhaust on my VW transporter had fallen off. Family recommended Maestro Yáñez as the man to go to for a replacement muffler. The shop was a bit primitive. The oxy-acetylene welder was one where pieces of calcium carbide were dropped into a water tank. The welding rod was twisted bailing wire. The helper was a 10 year old kid who was the maestro's apprentice. The entire muffler was formed out of pre-cut pieces before my very eyes -- out of mild steel using mild steel dies and hammering. The support bracket was 3/8" flat bar that needed a 3/8" hole and the hole was drifted cold using a maybe 2" dia. piece of round bar or maybe part of a tractor axle with a long tapered point on it. No pilot hole, just bang, bang, bang. The drift had a mushroom head on it of at least 3". It was, as Charles has said, very quick. The muffler was held in place and the bracket and other things were welded out of position by the helper using the twisted bailing wire. I checked out the weld later on and I was very impressed. I used the muffler for quite a while until the California Hwy Patrol stopped me in a roadblock and wrote me up for a non-stock muffler. I had chosen the "esport" model, and it was a bit ... er ... unh ... sporty sounding. No doubt in my mind if I had wanted a square hole for a carriage bolt Maestro Yáñez would have accomplished that using the same method. It is a bit easier if you happen to have a forge and heat the piece up to red hot, but not enough that Maestro Yáñez thought it worth the trouble. Being lazy, I tend to prefer redhot to cold, but not always. Besides, I am not yet a "maestro." L8r, L.H. in the almost spring like southern Ozarks. ------- Re: quick ,simple square holes Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Sat Mar 8, 2014 3:00 pm ((PST)) great story ..appeals to my depresion era instincts. at 14 i went to work one summer maybe 1946 at henry vogt machine co., 2000 employees, all the acetylene was generated in the shop. most auto repair shops had a small atlas or southbend, cause they repaired not replaced. sometime in middle 1970's a guy i had lunch w/ regularly told me the mechanic cud not repair the fuel pump on his 91 yr old mother-in-law's 1961 studebaker ....no kits, no new ones; called all over ...i foolishly said anything can be repaired ... next saturday the car arrived.....i ground the riviets off & the rubberized diaphram was split ...i told Bill to get me some membrane material ...i got something that looked like grey gasket material ...i complained; he said that is what they are using... i guessed at how limber to make it & bolted it back up .....i had just finished when son came down w/ a j c whitney catalog ..$8.75 plus shpg ....i ordered it & put it in trunk ...told bill he owed me $12 ...... the repair was still working a year later when she went into the retirement home. tnx for the story doc i was lucky enuf to grow up in a time when a kid cut get hired, first pd job was tightening spokes in pitmans bicycle shop 15 cents /hr ... age 11. ------- Cutting a keyway [myfordlathes] Posted by: "Brad Campbell" lists2009x~xxfnarfbargle.com yeldarb_llebpmac Date: Mon Jan 26, 2015 4:01 am ((PST)) G'day all, I have to cut a keyway in a 3/4" through hole in a piece of mild steel. I had planned to grind a tool and with the workpiece in the chuck, use the saddle handwheel to drive the carriage back and forward by hand to slowly cut the slot. A bit like a hand powered shaper. I'm sure people have done this before. Is there a better way? Am I likely to cause undue wear on the machine doing this? Regards, Brad ------- Re: Cutting a keyway Posted by: "David Littlewood" davidx~xxdlittlewood.co.uk dmlittlewood Date: Mon Jan 26, 2015 4:34 am ((PST)) Brad, I wouldn't have thought it would be a problem, as a one-off. If you want to do a lot of such work, Hemingway sell a nice kit to make a slotting attachment which fits to the saddle; I have one and it works quite well, but if I didn't have it I would not hesitate to do what you are proposing. If you have any concerns about the asymmetric forces, or wear on the rack, then use the tailstock ram (with a 2 MT blank arbour or some other such piece in it) to push the tool into the job. ------- Re: Cutting a keyway Posted by: "Alan Moore" a.j.moorex~xxbtinternet.com Date: Mon Jan 26, 2015 5:10 am ((PST)) Brad, I have used just this method to cut a couple of keyways in cast iron flywheels and mild steel crankshafts. I didn't want to strain anything, so I stuck to quite modest cuts, but it worked fine and didn't take as long as I expected. At the risk of stating the bleeding obvious, if you mount the tool sideways in the tool holder you can cut into the side of the hole and use the cross slide to advance the tool by the desired amount. You wouldn't want to do this every day, but for occasional use it's no problem. Regards, Alan ------- Re: Cutting a keyway Posted by: peterroachx~xxbtinternet.com x3cnc Date: Tue Jan 27, 2015 2:53 am ((PST)) Brad, You don't state how thick the piece of mild steel? or how big the keyway? Other options are: Make a Broach which could be used in a press or drill press EDM ? File it? Make "the piece of mild steel" from two pieces, and join, weld, braze as a single piece. Just thoughts... Peter ------- Re: Cutting a keyway Posted by: "Brad Campbell" lists2009x~xxfnarfbargle.com yeldarb_llebpmac Date: Tue Feb 17, 2015 5:16 am ((PST)) On 26/01/15, Brad Campbell wrote: > I have to cut a keyway in a 3/4" through hole in a piece of mild steel. > I had planned to grind a tool and with the workpiece in the chuck, use > the saddle handwheel to drive the carriage back and forward by hand to > slowly cut the slot. A bit like a hand powered shaper. > I'm sure people have done this before. Is there a better way? Am I > likely to cause undue wear on the machine doing this? Just an update (excuse the mish-mash of measurements). The keyway was a 3/16 wide slot, 32mm long and 1.1mm deep inside a 3/4" bore in a chunk of mild steel. What I ended up doing was using a bit of new 3/16 tool steel snapped to length and fitted perpendicular in a boring bar. I kept the as-delivered geometry and edges on the tool steel and just lightly stoned them to give them a really sharp edge. In increments of about 0.5-1 thou I just used the apron handwheel to cut the slot. Took a while and played merry hell with the arthritis in my left hand, but got the job done. I already had the topslide over at 29.5 degrees from cutting an M10 thread on the shaft, so I used that to feed the tool rather than the coarser cross slide adjustment. Now I can say I've done it. Next time I'll avail myself of the neighbour's slotter. On the topic of the M10 thread, my lathe pre-dates the special 21T gears for the metric threads and just uses the standard imperial changewheels to get "close enough". Over a 20mm length of M10 thread it was close enough that my M10 die did not complain at all. Brad ------- ------------------------------------------------------------------ This is just one of some 80 files about machining and metalworking and useful workshop subjects that can be read at: http://www.janellestudio.com/metal/index.html ------------------------------------------------------------------