Here find many users' tips on turning balls or spheres or curves using a metal lathe. BALL TURNING (a.k.a. RADIUS TURNING) is a turning operation that can be used to: 1 - put a smooth, rounded end onto a metal rod; or 2 - starting with a thicker rod, turn a ball on the end and thin the rest of the rod to suit the project; or 3 - turn a ball that is perfectly spherical (no rod left); or 4 - turn a concave curve into an object (make a depression). This subject that has been repeatedly featured in metalworking books and magazine articles. The latest (as I write this) Home Shop Machinist (HSM) magazine, November/December 2003, has the start of a 3-part article on making a fairly complex version for the third type (true sphere). This magazine can be bought from a news-stand or you can subscribe through Village Press, or you can find other articles through the publisher in back issues or consolidated books they publish. http://www.villagepress.com/homeshop/ The simplest way to put a ball on the end of a rod is to scrounge or buy a ball. If hardened, as in a ball bearing, it can be annealed before drilling an appropriately sized hole. John Bentley, in a message dated 30 Oct 2003, was talking about threading when the conversation turned to the ball handles he made. Here is a neat alternative to turning them from scratch. See the Threading text file on this site. (Sorry, but I don't have the space to repeat stuff in multiple files when the subject changes.) Or you could buy a commercial knob to screw/glue/solder/weld onto a rod. Or you could buy a commercial ball turning attachment suitable for your lathe. I see from an ad by OMW Metalcrafts that they have versions ready to go in two sizes. http://www.omwmetal.com/ (There are many other commercial units out there. Do a Web search.) If you look up some of the articles on making your own device, they range from simple to incredibly complex. It is interesting that one author in HSM's sister publication Machinist's Workshop in the April/May 2003 magazine wrote an article to prove you can do perfectly adequate ball/radius turning (types 1, 2, and 4) using standard lathe procedures and no special accessories. (See Village Press website above.) Author Guy Lautard wrote about a mathematical stepped approach to approximate a ball, followed by filing smooth, that will work with minimal equipment. See his books at http://www.lautard.com/ And then the horological approach (clock-making) is to turn the ball/radius freehand using a hand-held graver in an operation similar to woodturning. See http://horology.magnet.fsu.edu/wrsmith.htm And on both sides of the pond you can look through the excellent British magazines published by Highbury Nexus Special Interests Ltd for articles in their back issues -- see Model Engineers' Workshop. North American distributor is http://www.wiseowlmagazines.com/ And a web search or perusing the links off this site will likely find free advice and how-to articles, perhaps with pictures. 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. 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(c) Copyright 2003 - 2011 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. ====================================================================== From: Date: Fri Aug 25, 2000 12:25pm Subject: Radius cutter material. Would 6061 T6 aluminum be OK to make a radius cutter? What does Sherline use on their attachment? Thanks! Rogerio ---------------- From: Date: Fri Aug 25, 2000 1:53pm Subject: Re: Radius cutter material. On Aug 25, 4:25pm, videosx~xxm... wrote: } Would 6061 T6 aluminum be OK to make a radius cutter? What does } Sherline use on their attachment? Thanks! Rogerio When I made a clone of the Sherline radius attachment, I used cast aluminum jig plate, because I had some on hand. 6061 should work as well. I don't think it's really critical. Picture available at: http://blw53.freeyellow.com/radiustool.jpg Although in the picture it looks like it's spilling off the cross slide, it actually just fits within the length. This was the first thing I made when I got the milling column for my lathe. The first thing I made with the radius cutter was the brass ball for its own handle. -Brian -------------------------- From: Date: Fri Aug 25, 2000 9:05pm Subject: Re: Re: Radius cutter material. On Aug 25, 8:49pm, "John D. Guenther" wrote: } Brian, Nice job, looks like a fairly easy project. What thickness was the } material for the H part? The rest I can figure out based on center I used 1 inch thick jig plate - minus a couple thou practicing with the flycutter. } height. I will be making for another lathe. } Thanks for sharing your project with us, it is really neat! John Guenther -Brian --------------------------------- From: Ron Ginger Date: Mon Aug 28, 2000 3:45pm Subject: Re: Bride of radius cutter I think Joe Martin comments in the Tabletop Machining book that he tooks a different approach in his radius cutter. The more common approach is to have the cutter axis vertical, mounted on the lathe slide. With that you can make a radius with its center off the axis of the lathe. There is a guy that sells a conventioanl radius tool for the Sherline, at about the same price as the Sherline version. I dont recall the name now, but he has been mentioned here, and shows his tools at NAMES and probably PRIME. I think the Sherline web site has a pointer to him. I think its a more flexible tool than the Sherline version. ron -------------- From: Date: Tue Sep 12, 2000 00:46am Subject: Radius cutter finished. Finally finished my radius cutter. It is a copy of the Sherline's tool, at least as close as I could do from their ads. I posted a picture in files on a folder named Radius cutter. Everything came out great except the body anodyzing which turned out purple instead of black, I'l have to redo it and use dark blue as in the supports which came out with a nice dark blue, almost black. Thanks for all the suggestions and help! Rogerio Odriozola ----------------- Date: Tue, 2 Jan 2001 00:29:08 EST From: SLEYKINx~xxaol.com Subject: Ball Turning tool finished :) I have been thinking about all the different ways to make ball turning tools for my lathe and finally came up with a solution that works for me. Sort of a take off on the ones discussed on RCM using a boring head. I used the tool holder from the QC kist I bought from Harbor freight that is for holding a drill chuck. I made a brass bushing with a 1/2" bore and a new spindle for the boring head with a 1/2" shaft long enough to pass through the toll holder/bushing and attach a handle. I then made a short boring bar and mounted a HSS cutting tool 90* to the normal way and presto I can make nice shiney round ball on the lathe now. First one is going on the handle for the ball turning tool :) I just used a long 1/2" bolt and the hex head is not real comfortable. I ground a round nosed tool bit and that seems to work well with this setup. Regards Glenn Neff Medford, OR --------------------------- Date: Mon, 21 May 2001 04:31:21 -0000 From: "Doug Powell" <4machiningx~xxhome.com> Subject: Re: Peatool ball turning jig? The Taig radius turning attachment is part # 1210 and was introduced about a year and a half ago. Taig lists it for $19.50. Doug Powell Taig Tools Dealer ---------------------------- From: Ron Ginger Date: Thu Jul 6, 2000 9:34 am Subject: Re: [sherline] Ball turning tools(Was Rotating Table) Bill Rutiser wrote: > > That would be Joe Osborn of OMW Metalcrafts. www.omwmetal.com > > The OMW tool rotates a bit in a horizontal plane around vertical > > axis. The Sherline device rotates the bit in a vertical plane > > around a horizontal axis. I don't immediately see how the Sherline > > design could be used for the orginal poster's problem but > > OMW's should work. The Sherline one would work the same way- its center of rotation is on the centerline of the lathe, just in the other plane. You would simply adjust the tool to extend out past the centerline by the desired radius, where for turning a ball you place the tool below the centerline. Identical to Joes device, just his is mounted 90 degrees to the Sherline version. Both tools would suffer from long overhang of the tool if you were trying to do a very big concave radius. ron ----------------------------- From: "Bill Rutiser" Date: Thu Jul 6, 2000 10:14 am Subject: Re: [sherline] Ball turning tools(Was Rotating Table) The original poster's problem was to produce a groove with circular cross section. In that application the ball turning tool's axis must be displaced from the spindle's axis. With the OMW tool this is accomplished by adjusting the cross slide. The Sherline design would need some sort of vertical adjustment. Bill Rutiser Gaithersburg, MD -------------------------- From: Ron Ginger Date: Thu Jul 6, 2000 11:50 am Subject: Re: [sherline] Ball turning tools(Was Rotating Table) You are correct. The OMW attachment is more flexible in that regard. The Sherline one can only make balls whose axis are concentric with the work. ron ------------------------- From: rdavx~xxv... Date: Fri Jul 7, 2000 3:49 pm Subject: Re: Rotating Table --- In sherlinex~xxegroups.com, Ron Ginger wrote: > Robert Davies wrote: > > I am cutting a radius in the center of a 1/4" aluminum rod, like this: > I dont think a rotary table is the way to do this- its a job for one of > several ball turning tools. Sherline sells one, that mounts over the top > of the work. There is also a fellow that sells a nice one, he demoed at > NAMES, but I dont recall his name or URL. There are also MANY plans for > ball turning tools in various model engineering magazines. > For one this small I would use a form tool. Just grind the end of a 1/4" > lathe tool to the required radius and plunge cut it straight in. Unless > the grove you want to cut requires extremely accurate radius- maybe to > roll ball bearings in- a freehand grind up against a template should be > fine. Make a template by drilling and reaming a very clean hole in a > piece of sheet metal, then cut away one half the metal to leave a > half-round template. Hold this up to a light against the tool and grind > away until the fit is as good as you can make it. > Form tools can be tricky to get right- they will chatter if made to wide > or taking to deep a cut, but since you are doing 1/4" rod the radius can > not be very large. ron Thanks, Ron. I am trying to do cuts similar to what is shown in the Sherline Manual "Tabletop Machining" on pages 214 and 327. I think my problem is that both of those pictures show setups with the mill rather than with the lathe/mill column. I just purchased a mill xy table and I expect this will resolve my problem. Robert Davies ----------------------------------- Date: Wed, 4 Feb 2004 06:47:49 -0500 From: Kuechenmeister Subject: Radius Turning I started out this weekend, intent on making some sort of a ball turning attachment for my lathe. I looked through a couple magazines and realized that the compound is a pretty good ball turner, as it is installed on the lathe. This sure looks like an obvious way to turn an occasional radius. Besides increased wear on the mount, is there any other problem that I'm overlooking? Thanks, Dave Kuechenmeister Lawrenceville, GA ---------------- Date: Wed, 4 Feb 2004 13:44:33 -0000 From: "Ernest Lear" Subject: Re: Radius Turning Dave How are you going to control the direction and cut of the tool? A loose compound held in the hand to control the cut could give you a big surprise when the tool dig into the metal that you are trying to shape. And don't forget, the support casting of the mount on the cross slide is very brittle and will break very easily when the cutting tool dig in. This is very well helped by the loose compound, the leverage between the tool tip and the centre of the mount and the sharp rapid downward force applied at the tool tip. Regards Ernest ---------------- Date: Wed, 4 Feb 2004 09:41:43 EST From: jmartin957x~xxaol.com Subject: Re: Radius Turning It works, I've done it. Not for balls, but for concave pieces. Turning a new spherical washer for the toolpost, for example. There are a few precautions, most of which are common sense. The compound swivel has to be adjusted pretty closely. Loose enough so that it will just swivel, but tight enough so that there is no rocking or other play. You need as much control over the swiveling as possible. A long bar clamped to the back of the Armstrong tool holder, or clamped into the toolpost along with the bit, will allow you to feed slowly and steadily. The bit should be ground so that it is pretty much neutral. In particular, you don't want one with so much rake that it wants to self-feed. Feed slowly and with small depth of cut, and listen and feel what the lathe is trying to tell you. Convex surfaces may be more difficult than concave, due to clearance problems and the position of the cutting edge versus the axis of the compound swivel. You might have to work with the compound facing backwards, or with the compound in the normal position but cutting on the back side of the piece with an upside-down cutter. Adapt and improvise. And let us know of your success or failure, so that everyone else doesn't have to reinvent the process. I've also done some hand turning - turning steel with hand held tools as on a wood lathe. Generally for concave rather than convex surfaces, for profiles too large for a form tool. Main concern there is keeping tool overhang to a minimum. John Martin -------------------- Date: Wed, 4 Feb 2004 09:52:42 EST From: Sagebush9x~xxaol.com Subject: Re: Radius Turning I've tried that on my 12", 28990-it works OK for pretty small radii, but you can't get enough offset from center to make a very big ball-on the 12", it is rigid enough if you are VERY careful & take real light cuts, but I don't know if I'd try it on the older smaller lathes W/a a lighter compound...a recent issue of HSM or MW had plans for a pretty simple ball turner, don't remember which mag right now. HTH Ron in CO... -------------------- Date: Wed, 04 Feb 2004 11:22:08 -0600 From: Jon Elson Subject: Re: Radius Turning The big problem is to make a toolpost that holds a tool BEHIND the center of rotation of the compound. You can't do it with a standard toolpost, the way most lathes are set up. Jon ----------------------- Date: Wed, 04 Feb 2004 16:30:50 -0000 From: "kplus13" Subject: Re: Radius Turning Thanks for the advice. The ball turner in the latest HSM/MW [3-part article started with Nov/Dec 2003] is what I will probably make, if only for the larger radii available. What made me think of using the compound is that this accessory just sits on top of the compound like a tool holder would. I've got some one inch brass that I am going to experiment on. I'll let you know how it goes. Regards, Dave Kuechenmeister --------------------- Date: Wed, 04 Feb 2004 10:35:47 -0600 From: xlch58x~xxswbell.net Subject: Re: Re: Radius Turning There was an article years ago in one of the village press magazines that showed how to make a plate to insert between the compound and its mount. It bolted to the cross slide and had several predrilled holes for mounting the compound to cut common radiuses. Very simple. This idea could be adapted to the Atlas, though it was applied there to a Southbend. Charles --------------------- Date: Wed, 4 Feb 2004 12:00:00 -0500 From: "Dr Robert Harms" Subject: Re: Re: Radius Turning I have never needed to turn a precise radius so if your need is to do so discount what follows (although Im not sure why the radius would need to be exact unless it was to fit into some corriisponding type of female recess). All of the radius turning that I have needed to do is cosmetic like on acorn nuts and the like. To make such products, I simply rough them in and then profile them with a 4 1/2 inch hand held grinder while the piece is spinning in the chuck. Merely cover the ways and grind away. The fact that they are spinning in the chuck assures that they are symmetrical. Multiple pieces can be compared to templates. Again, this is for cosmetic rather than precise pieces. --------------------- Date: Thu, 05 Feb 2004 02:40:03 -0000 From: "mikehenryil" Subject: Re: Radius Turning Jerry Howell has a set of plans for a ball turner/radiusing attachment. It's designed for a different lathe, but it wasn't hard to modify the base to fit a Craftsman 12" lathe. You can see a picture of the the one I made for my old Craftsman lathe in Jerry's gallery: http://www.jerry-howell.com/Cust-Pix-5.html The plans were good quality and only $10: http://www.jerry-howell.com/Radius.html Mike ------------------------ Date: Thu, 5 Feb 2004 08:53:10 -0000 From: "Alan Barnett" Subject: Re: Re: Radius Turning Have a look here under Home Shop Software it might help. http://www.geocities.com/mklotz.geo/#shop Regards Alan ------- NOTE TO FILE: Marv Klotz's site has MANY useful programs for the home shop machinist to simplify cutting gears, knurling, etc. etc. etc. ------- Date: Wed, 23 Feb 2005 18:54:38 -0500 From: "Chris Boyer \(CB\)" Subject: Re: Ball turning [Prints_and_Plans group] "wesley5060" wrote: > Hi all any one got a drawing on how to make a ball turning attachment > for the lathe please. wes Not a drawing but see: http://bedair.org/Ball/ball.html There is a lot of useful info on the other pages as well. Many versions of this tool have been made. ------- Date: Fri, 25 Feb 2005 04:51:19 -0000 From: "Ned Seith" Subject: Re: Ball turning [Prints_and_Plans group] Greetings, I use a custom carbide insert tool holder for ball turning. Pictures: http://users.rcn.com/seiths/projects/tooling/index.html Ned ------- Date: Thu, 24 Feb 2005 14:42:46 +0000 From: Clive Foster Subject: Re: Ball turning [Prints_and_Plans group] Wes, there are loads of variations on the horizontal sweep design available as plans from various magazine back numbers. I've got at least 4 in the archives varying from rudimentary to excessively complicated multi- adjustable worm drive beasts. Depending on your particular time/work/scrapbox contents situation I think the best way of doing the job is to make a vertical sweep version using a cheap boring head for the tool holder. Most of the inexpensive boring heads screw on the arbor so all you have to make is a block for the toolpost bored on centre height for the pivot and a hefty pivot bar with a handle one side and a threaded spigot to fit the boring head on the other. By far the best solution if you have a milling machine as now you have a dual purpose tool! That's the way I'm going to make mine when I've collected enough round tuits! Clive ------- Re: Ball/Radius turning tool [atlas_craftsman] Posted by: "Glenn N" sleykinx~xxcharter.net Date: Wed Jan 17, 2007 9:56 am ((PST)) "mrkharriss" wrote: > Hi, does anyone own one of these? If so, where did you get it and how > well does it work? Having only just bought my 10" F model, I'm in the > process of assembling a selection of tools which will be of use to me > as asnd when future projects arrive. Has anyone made one and if so, > can you please point me towards the plans? Thanks Mark I made one by mounting a boring head on a shaft sized to fit the boring bar holder on my QCTP. Put a cutter bit in a piece of rod I broached a square hole in and I can do a ball close to 2" in dia very quickly and easily. I posted pictures of it many moons ago but if you can't find them or want some more holler. Glenn ------- Re: Ball/Radius turning tool Posted by: "Joe R" jromasx~xxcolumbus.rr.com Date: Wed Jan 17, 2007 4:15 pm ((PST)) Mark: I recently made one of these. http://alisam.com/page/14g9f/Metalworking.html I also made one like Glenn mentioned. I liked the one in the link better except for one thing. If you don't have a broach just drill a round hole! Otherwise you'll be trying to get the bit to fit right. ------- Re: Ball/Radius turning tool Posted by: "Jim" clipper_2x~xxcharter.net Date: Wed Jan 17, 2007 5:36 pm ((PST)) Go to the files section and check this one out. http://groups.yahoo.com/group/atlas_craftsman/files/Ball%20turn ing%20attachment/ I like this one about the best of all the designs I've used. Jim ------- Re: Ball/Radius turning tool Posted by: "Zort C. Brown" mtrsicklemanx~xxearthlink.net Date: Wed Jan 17, 2007 6:50 pm ((PST)) Mark: I just bought a ball turning frame kit on eBay. Nice quality -- just needs to be finished. His current auction is # 180075693819 He also has a website where he sells them around for $25 + shipping. www.alisam.com Zort Brown Lincoln, NE ------- Re: Ball/Radius turning tool Posted by: "Bruce Koch" tkd_master38x~xxyahoo.com Date: Wed Jan 17, 2007 7:25 pm ((PST)) Hey Gang, I have a Holdredge that I bought on Ebay some time back; it is a big heavy duty thing and well constructed. It mounts onto the t slot in the compound. So far I have not tried it on my Craftsman or Atlas, but afraid that it will be too big for a small machine to handle. It worked fine on the 13 " Harrison at school. A smaller version would be great. This thing will do concave and convex, so it really handy, much faster than grinding a radius tool. Here is another thought, for a small lathe something that fits onto the cross slide rather than the compound might be ideal. These things do not have to be mounted vertically; no reason that it cannot be mounted horizontally and swing upward to turn a radius. It is my understanding that Sherline mini lathes use such an arrangement. One more thought, why all the fuss over broaching a square hole? HSS comes in round stock and is just as easy to grind a tool on it. Save a lot of hassle. Bruce ------- Re: Ball/Radius turning tool Posted by: "azbruno" azbrunox~xxyahoo.com Date: Wed Jan 17, 2007 8:16 pm ((PST)) Guy Lautard, in his excellent book "The Machinist's Bedside Reader", discussed a method of turning radii using a parting tool. In the same vein, I do a lot of radius ends using nothing more than a turning tool and math. A radius is a part of a circle and the points on a circle can be calculated with a formula. Earlier this week, I was putting 5/16" radius ends on 5/8" diameter rods, the ends being a semicircle. Using a series of successive cuts where I'd move the cross slide in .010" on each cut, and then following up with a file, I could do the job in about 5 minutes. I do this a lot, so I made a simple word macro that lists out all the cross slide and carriage movements. Of course, one does need accurate measurements and I have a DI on the cross slide and on the carriage. My next task is to radius from the front, not the end, so I'll need to use the Lautard method with the parting tool, I suspect. Bruno ------- Re: Ball/Radius turning tool Posted by: "n8as1x~xxaol.com" n8as1x~xxaol.com Date: Wed Jan 17, 2007 8:34 pm ((PST)) FWIW ...have made balls, radii, curves using hand held scrapers made from old files used in manner of a wood lathe ...yes works on mild steel also ...use back of bit holder for a rest & grind a rt /left skew from flat file, round point from 1/2 round & round files.....earliest metal lathe work was done in this manner & even 80 yrs ago, fillets in flanges were smoothed this way best wishes docn8as ps ...for one-offs, it goes faster than setting up for ball turning ------- Re: Ball Turning on Taig Lathe [taigtools] Posted by: "Rich Crook" richcrook9418x~xxyahoo.com Date: Sat Jul 7, 2007 1:21 pm ((PDT)) At 11:10 AM 7/7/2007, you wrote: >I've purchased a Small Ball Turning Attachment from omw: >http://www.omwcorp.com/pr od_srt.shtml >Can anyone offer any advice using this item? What's the best way of >setting up the tool and using the attachment? Make sure your tool point is centered vertically, & take light passes till you get a feel for it. If you can, measure the distance from the face of the movable "C" toolholder to the pivot centerline - then you can set the tool to a specific cutting radius with a depth gage or mike. If you have a caliper with a depth rod, use a parallel faced block (of known thickness) with a hole drilled in it for the depth rod to pass thru. Figuring out when the pivot center is exactly on the spindle center isn't hard *if* you know what the cutting radius is set to. If you make a straight tool holder (to replace the "C" holder) you can cut concave radii with it. I've used a much bigger version of this (on a bigger lathe) to make hemispherical plastic shells with a constant wall thickness; it worked very nicely. Note: for a full concave hemisphere, you'll need a tool with an offset tip, like a boring bar, or an OD turning tool. Otherwise, use a centered "V" point tool (like a threading tool.) Rich ------- Re: Ball turning attachment [atlas_craftsman] Posted by: "Russ Kepler" russx~xxkepler-eng.com Date: Thu Nov 15, 2007 6:49 am ((PST)) On Wednesday 14 November 2007 22:26:43 pjamesanderson wrote: > Anybody have one for sale or know where I can get one? I dont have > time to make one and would like to buy one for my 12" craftsman. I can > pay with paypal if desired. Thanx...Pete The Shaplane radius tools from Eagle Rock are OK. Here's a link: http://www.eaglerockonline.com/index.php?Catalog=View&ProductLine=32 You can sometimes find them on eBay. Other than that the Holdridge tools are about it. I made the MLA ball turning attachment and it went pretty well - it's a fast kit to make. ------- Re: Ball turning attachment Posted by: "Russ Kepler" russx~xxkepler-eng.com Date: Thu Nov 15, 2007 10:06 am ((PST)) On Thursday 15 November 2007 Jay Greer wrote: > Question, Will the Shaplane radius tool work on the six inch Atlas? Nope. You might make something that would work, but the smallest of the Shaplane tools is too big for the 6". ------- Re: Ball turning attachment Posted by: "Brian" brianmc4x~xxcomcast.net Date: Thu Nov 15, 2007 7:16 am ((PST)) I would not bother with a ball turning attachment after using a corner rounding end mill, mounted in boring bar tool post and getting good results. The only problem is that you're cutting in reverse from the back side. Brian ------- Re: Ball turning attachment Posted by: "Jim Ash" ashcanx~xxearthlink.net Date: Thu Nov 15, 2007 10:18 am ((PST)) Not that this really answers your question, but: If you've just got one ball-turning job to do, you can skip the attachment and use the method described in Guy Lautard's Bedside Readers. It basically means cutting the ball in steps, then bluing and lathe-filing until the blue stripes disappear. I've turned a few balls this way. I put together a spreadsheet showing me the coordinates I need for each cut, then print it and check each step off as I go. It's obviously more tedious than using a ball-turning attachment, but for my frequency of need I can't justify spending the bucks. Jim Ash ------- RE; Ball turning attachment Posted by: "wkmacy" wkmacyx~xxgso.uri.edu Date: Thu Nov 15, 2007 1:10 pm ((PST)) Hello all -- check out Alisam Tools at http://alisam.com/page/14g9f/ Metalworking.html for 2 sizes of ball turning kits at very reasonable prices. The frames are laser-cut and require only drilling several holes, a short length of 1/4 in drill rod, and a few set screws to complete. NO milling is needed, but you must be able to drill the axle/pivot holes accurately. Best of luck, Bill from RI ------- Re: Ball turning attachment Posted by: "Bobby May" widgitsx~xxsbcglobal.net Date: Thu Nov 15, 2007 12:07 pm ((PST)) Check out the files directory on the atlas_craftsman main page. Real cool layout from the 60's for how to make and use one of these radius attachments. Different from a Holdridge type, just swings the compound rest. Something to think about, pretty cool!!! Later Bobby ------- Re: Basic Milling Question [sherline] Posted by: "chieftoolmaker" chieftoolmakerx~xxearthlink.net Date: Fri Oct 31, 2008 2:46 am ((PDT)) On October 30, 2008, Jerry Kieffer wrote: > Greg: This will depend on your selection of tooling and how it is used. I have posted a photo under my name of a finial machined by a student in a basic lathe class. It was machined on a Sherline Lathe with a AR-4 and E-4 brazed carbide tools along with a Sherline rear cut-off tool and standard tool post. The headstock was not rotated and no files were used. A final very light surface finish was applied to remove/blend any minor tool marks with 600 grit Silicon Carbide paper as with any machined surface. This exercise was done to demonstrate the flexibility of certain types of lathe tooling and the efficient use of ALL available cutting surfaces. It of course also demonstrated the ability to easily machine shapes with standard factory stock lathe tools without form tooling. Form tooling is highly desirable in many cases but can take far more time to construct than doing simple one off shapes with standard tooling. < Mr. Good Buddy Kieffer, Your mention of form tooling brings to mind yet another way of creating curves, radii, etc. on the lathe. Form tooling on the Sherline is possible using the method shown on page 162 in "The Sherline Accessories Shop Guide". Form tools create a lot of resistance due to the large area of contact. I would like to cite the use of a lathe duplicator. There, a simple (or complicated) template is used to have a follower point/stylus trace the shape ground or formed in a flat template and the toolbit will follow the path to create that desired form. Also, it is common to clamp a "master" in the duplicator (such as making many cannons for ship models) which is not flat but the actual part. Duplicators for the Sherline can be purchased and/or made. Later, Jerry G (Glickstein) P.S. I would like to know where the heck you got such a large quarter. ------- Re: Basic Milling Question Posted by: "n2562001" jlkiefferx~xxcharter.net Date: Fri Oct 31, 2008 8:45 am ((PDT)) > I would like to know where the heck you got such a large quarter. Mr. Buddy: They are of course machined to the size required. How do you do yours?? Jerry Kieffer ------- Re: Basic Milling Question Posted by: "William Rutiser" wruyahoo05x~xxcomcast.net Date: Fri Oct 31, 2008 7:23 am ((PDT)) Jerry: Nice work. Can you say a little more about how it was made? Was the final shape specified in advance? Could the technique produce a set of four matching finials? Approximately how many times was the tool post repositioned? Thanks, Bill ------- Re: Basic Milling Question Posted by: "n2562001" jlkiefferx~xxcharter.net Date: Fri Oct 31, 2008 9:36 am ((PDT)) Bill: This part was machined after a 15-20 minute demonstration of the process. The general shape of the Finial was specified but the overall size was up to the student. For the most part the process involves using lathe tools with many cutting surfaces and repositioning the tool post to make maximum use of those surfaces. The standard tool post is used because it is non intrusive and literally only takes two seconds to reposition. In addition fine detail can be done by coordinated movement of both handwheels at the same time in .001"-.003" steps. Coordinated continuous movement of the handweels is next to impossible -- however in very small steps it is very easy. Additional matching parts will probably not be as dimensionally accurate as form tooling, duplicators or quality CNC work, but generally visibly accurate and closer than graver work. It is taught as part of a number of ways to make full use of a Lathe and tooling. And of course much easier to demonstate than to explain. Jerry Kieffer ------- Re: Basic Milling Question Posted by: "Jim Ash" ashcanx~xxearthlink.net Date: Sat Nov 1, 2008 5:47 am ((PDT)) I turn reasonably accurate (+/- a mil, I'm guessing) hemispherical surfaces (balls) regularly, effectively using the techniques described. If the surface can be represented mathematically (or even with a set of coordinates), it can be made. It doesn't have to be spherical, just definable. I happen to enjoy combining math with machining, although the process can get to be a bit tedious. I've made a number of 1" balls by cutting 'steps' around them (kinda like latitude lines), bluing them, lathe filing just until the bluing is gone, then finishing with sandpaper, polishing, etc. I typically will cut 20-25 steps per half of a 1" ball, depending on my patience levels that day. The more steps, the more lathe cuts (and the higher probability I'll do something stupid like mis-counting handwheel turns), but less filing, and it's more accurate. If you cut down the number of steps (and consequently increase the step size), you're filling in the in-between spaces with eyeball approximation of the surface and I suppose it could get inaccurate. I've never tried hand-graving one and comparing it against a reference as I go, but it's been on my list. Some observations: 1. Don't even pick up a file for use in this process without having a handle on it. An exposed file tang is asking for it; you might as well attempt the process with an arrow aimed at your chest. If you're really cheap, chuck up a chunk of wood (an old broom handle piece?), round off the end a bit, and drill the other end. Extra points if the drill is tapered, but not necessary; as long as file file fits snugly, the working action of the file will force it deeper into the handle, not out. More extra points if you cut a groove near the file end and wrap it tightly with wire so the pressure from the file won't split the wood if it's weak at that point. Not a fancy solution, but much, much safer than nothing. 2. Keep the file clean. Especially depending on the material, they can clog up fast. You'll be cruising along, working a particular area on the file, then move it and it all of a sudden works a lot faster. This also creates inaccuracies in the work. 3. Assuming your lathe is turning at a constant speed, the larger the diameter of the part where you're filing, the faster its lineal speed becomes, and this is very noticeable when lathe filing. When turning spheres, the file barely does anything at all when close to the center. If you're not careful, you can over do it on the outer part and not yet be finished on the inner part. I tend to start slow on the outer part, then work my way in to the smaller diameters, speeding things up as I go. A good (even a not-so-good) production CNC lathe is set up to operate at the maximum cutting speed for the setup and does this automatically. 4. I prefer the step method, and honestly haven't tried using the compound for ball-turning on my Sherline lathes, but I have on larger lathes. I just went and looked at my compound (the standard Sherline-issue unit). It won't back off enough to cut convex curves, so you'd have to rig some kind of interesting way to mount the cutting tool for it to work (maybe to be above the existing mechanism instead of in front of it, then strap on the riser blocks to match up to the tool). Not a pretty picture, but I offer it as a possibility, albeit a pretty lame one. 5. If you've got a lot of pieces to make and there's a chance you could get bored/frustrated with the process, spring for a ball-turning tool. But shop carefully. I'm interested in turning toroids (dougnuts) or maybe even 'footballs', not just spheres. The difference is that I've got two radii to consider; the one centered about the spindle axis, and the one centered where ever you need it to get the shape you want, perpendicular to the first. A sphere is a special case of this where both the center lines happen to intersect. Sherline's ball-turning tool assumes these centers to be the same, and adjusting it to do otherwise requires shims, risers or some other annoying 'fix' to get it to work for you. OMW has a more 'traditional' ball-turning tool, but it can't handle the sizes I want (a large diameter, but very thin dougnut), or I'd have picked it up already. I've been too lazy to design the tool I want, and the step method works for anything if the work fits on the lathe. Jim Ash ------- Re: Duplicator [sherline] [was: Re: Basic Milling Question] Posted by: "DA Dossin" danatlx~xxyahoo.com Date: Fri Oct 31, 2008 11:02 am ((PDT)) Subject: Duplicator The only one I have seen for the Sherline can be found at the below URL. http://vanda-layindustries.com/html/duplicator.html I have one. Others have them. I have not spent much time with mine so I cannot say it will work flawlessly but, the time I have spent, I can see the value in it. Perhaps some of the other owners can give you an indepth review of it. Dan ------- Re: lathe adapter for turning a ball [atlas_craftsman] Posted by: "Robert Silas" robert.silasx~xxvideotron.ca Date: Fri Jan 16, 2009 10:53 pm ((PST)) Unfortunatelly I do not remember where did I see photos and drawings, some blue-prints too, about an adapter for turning a ball on the lathe. In case any of you came across the site, or a book on a site, about such an adapter please let me know. I know how it works, I could make an adapter myself, but the one I saw was such a neat construction that I'd like to find it again. Thanks in advance Robert ------- Re: lathe adapter for turning a ball Posted by: "ahz" ahzx~xxinsightbb.com Date: Fri Jan 16, 2009 11:10 pm ((PST)) Try http://bbs.homeshopmachinist.net/ This was a topic of discussion in the last 2 weeks. ------- Re: lathe adapter for turning a ball Posted by: "Geoff Crimmins" gcrimminsx~xxyahoo.com Date: Sat Jan 17, 2009 7:41 am ((PST)) http://www.bedair.org/Ball/ball1.html There's a link to a nice ball turner. It will also turn coves. Geoff ------- Re: lathe adapter for turning a ball Posted by: "Darren Dean" we4212x~xxgmail.com Date: Sat Jan 17, 2009 8:16 am ((PST)) Here's another, quite a few projects on this forum http://madmodder.net/index.php?topic=319.0 Regards Darren ------- Re: lathe adapter for turning a ball Posted by: "Scott Henion" shenionx~xxshdesigns.org Date: Sat Jan 17, 2009 8:47 am ((PST)) I have added to my web pages a description of the ball tuning attachment that came with my lathe. It is a bit simpler: http://shdesigns.org/Craftsman-12x36/ballturn.shtml Scott ------- Re: lathe adapter for turning a ball Posted by: "Joe R" jromasx~xxcolumbus.rr.com Date: Tue Jan 20, 2009 6:44 am ((PST)) Robert. There are many examples on the web. But most are very elaborate. I've put some pdf files in a file folder called "More Ball Turning Fixtures" on the group site. They are fairly simple. For the most vestal and simplest to make I suggest blending the modern one using the QCTP with the second 1922 popular Science version. I have built the kit I got on the web (can't find where now) and the modern QCTP version. http://groups.yahoo.com/group/atlas_craftsman/files/More%20ball%20turn ing%20fixtures/ Joe R. ------- Re: internal ball / sphere turning [MyMyford] Posted by: "mike.crossfield" mike.crossfieldx~xxvirgin.net Date: Fri Sep 11, 2009 2:02 am ((PDT)) On Thursday, September 10, 2009, hierophylus wrote: > I would like to make a ball holder ( and turn the ball ). Geo Thomas talks about it in his book (p 102.)but I am too much of a novice to make the tool from his drawing. Can anyone direct me to better info , or indeed the tool. Cheers Nick < Nick: The device described by GHT was designed by J A Radford. Its construction is fully described in JAR's excellent little book "Improvements and Accessories for Your Lathe" from Tee Publishing. Still in print and availailable from the usual suspects. It's a very good tool which is a pleasure to use - I made one myself several years ago when I was a raw beginner, and I still use it regularly. If you follow the instructions in the book carefully, you should have no problems making it. Mike ------- Re: internal ball / sphere turning Posted by: "ravensworth2674" ravensworth2674x~xxyahoo.co.uk Date: Fri Sep 11, 2009 5:51 am ((PDT)) Mike is quite right about Jack Radford's book. It is fair to mention that HemingwayKits is believed to have simplified it. Thomas designed the Versatile Dividing head and a small boring head. Used together, they make up a ball turning attachment. Sort of three for the price of Two, eh? What I was commenting on initially was the simpler tool which Thomas made -- and which disappeared in his workshop. Designs for such things are legion and many are so difficult to make without having a ball turning attachment (yes, I know). Perhaps it is worth mentioning the equally interesting web site of a Mr G.W. Howe called Workshop Projects 1. Mr Howe has a ML7 and describes some of his projects. Again, the Chris Heapy site is now old and somewhat tatty and neglected but it does contain invaluable information. It now means that the actual blueprints may not be obtainable now (I can't, but well?) but most of Mr Heapy's stuff is well worth a read. I hope that you will benefit from it as much as I have. Maybe others will add more of their 'Favorites' N ------- Re: internal ball / sphere turning Posted by: "stevenson_engineers" johnx~xxstevenson-engineers.co.uk Date: Fri Sep 11, 2009 4:02 pm ((PDT)) I really rate the Radford book and articles. Everything he did had a use and purpose, many going on the enable the next episode to develop. You got the impression that it was 90% use, 10% show. Thomas OTOH always came across to me as 90% show and 10% use. I find it amusing that he had a need to visit Jack Radford but Radford for some reason never had a need to visit GHT. Many of GHT projects were variations on an existing theme: staking tool, dividing head, etc. Radford's were unique, thread milling, et al. John S. ------- Re: Turning a hemi-sphere [MyMyford] Posted by: "ravensworth2674" ravensworth2674x~xxyahoo.co.uk Date: Fri Oct 23, 2009 6:01 am ((PDT)) "peterscott147" wrote: > I want to make a component in aluminium with a hemi-spherical end, approximately 1.1/8" in diameter. It has to 'look right' but does not need to be very accurate. Either I chamfer it several times and then finish it by hand or .... or what? Most ball turning attachments which I have seen are complex/expensive, including the 'relatively' simple device in George Thomas's book. In the Arc Euro catalogue there is a very simple design see http://www.arceurotrade.co.uk - search for 'radius turning' Has any one any comments on such a system or have any of you other advice as to how to tackle this job. I am very much a beginner. Peter < Peter: Frankly, there is much to learn from the 9X20Lathes Group. In the files section there is a write up of you to overhaul a 9x20 but it also includes a simple(r) design for a ball turning attachment which utilises a carbide tool insert at centre height. Carbide tooling isn't me( I have said this many times) but as a somewhat raw beginner, using a tip would literally turn the hemisphere in seconds. You wouldn't have to fart about with toolgrinding, filing, sticking alloy and you name it. You might enjoy some of the other bits in the groups files. Good Luck Norman ------- Turning a hemi-sphere Posted by: "HG" hgx~xxallthemunros.com Date: Fri Oct 23, 2009 5:30 am ((PDT)) I'm a big fan of Guy Lautard's "Incremental cut" method, which involves making a number of small cuts with the tool positioned by coordinated movements of the slides according to tables he has published, or which you can calculate for yourself. The result is the required shape outlined in the form of a number of small steps or ridges. You then finish by filing. You could see it as a more refined version of your chamfering idea. Henry ------- Re: Turning a hemi-sphere Posted by: "Bob Minchin" bob.minchinx~xxntlworld.com Date: Fri Oct 23, 2009 6:23 am ((PDT)) Peter, Do you have a boring head? If so this can be mounted in a simple horizontal pivot in the tool post with the axis of rotation at 90 degrees to the lathe axis. A simple cutting tool with good clearance angles all round can easily make concave or convex hemispheres or even virtually complete balls. Let me know if you want me to take some photos. Bob ------- Re: Turning a hemi-sphere Posted by: "Bob Minchin" bob.minchinx~xxntlworld.com Date: Fri Oct 23, 2009 12:01 pm ((PDT)) Chris, I'm not going to be in the workshop for a few days so I've included a link to someone else who has done the same thing. http://www.gateho.nildram.co.uk/ball_turn.htm The original work was done by the late Jack Radford in NZ many years back. HTH Bob ------- Re: Turning a hemi-sphere Posted by: "peterscott147" peterx~xxpjscott.freeserve.co.uk Date: Sat Oct 24, 2009 7:01 am ((PDT)) Peter Dobson wrote: >Well fortunately, Chris Parr came to my rescue. He kindly send me a Link by email which leads to Steve Bedair's website with description, pictures, drawings and even video of the ball turning attachment. The link is http://bedair.org/Ball/ball.html I like the look of that design. Very interesting and for those who don't want to make one, RDG sell them. Wonder what the quality is like? I should have rasied the issue a week ago as I went to the Model Engineering exhbition last Monday and could have had a look at one there. Ah well that's life. Peter ------- Plans for very nice ball turner [atlas_craftsman] Posted by: "wheezer" wheezer606x~xxverizon.net Date: Wed Dec 30, 2009 4:14 pm ((PST)) Group: Pix and drawings for a very nicely made ball turner. Go to the page bottom for .jpg and .dxf files. http://www.lepton.com/metal/ball_turner.html lance ------- Re: Plans for very nice ball turner Posted by: "Rick Sparber" rgsparberx~xxaol.com Date: Thu Dec 31, 2009 4:36 pm ((PST)) I wonder if I can mount my mill's rotary table on my lathe and clamp a cutter on top in order to turn balls. Rick ------- Re: Plans for very nice ball turner Posted by: "William Abernathy" williamx~xxinch.com Date: Thu Dec 31, 2009 4:41 pm ((PST)) In theory, that would work. The devil's in the details. You'd need a tool holder at the right height and you'd need to center the axis of rotation under the center of the lathe. And the whole works would need to clear whatever you were turning. William A. ------- Re: Plans for very nice ball turner Posted by: "Rick Sparber" rgsparberx~xxaol.com Date: Thu Dec 31, 2009 4:43 pm ((PST)) William, I'll let you know if I get it to work. I normally turn balls by using Manual Numerical Control. Rick ------- Ball Turner for 10" atlas lathe repost [atlas_craftsman] Posted by: "swagrimreaper" swagrimreaperx~xxyahoo.com Date: Fri Jan 7, 2011 8:07 am ((PST)) Somehow my Original Ball Turner thread got mixed up with a quick change tool holder thread, so I have deleted my Original post and started this one with all the posts that were under it. I made a ball turner for my 10" atlas lathe. It might also work on the 12" but I am not sure what size the compound mount lug is. I posted pics in the Photos section. The ball turner uses TNMG 322 inserts and will turn a ball up to 2" inches diameter. The handle ball end is the first ball I turned with it. The ball turner mounts on the carriage the same way the compound does. I added a grease zerk so I could grease it without having to take it apart. This ball turner works like a champ. Doc Says - Where do you get your metal stock? Dave Beckstorm says - Tha'ts the exact same design I started working on a couple days ago. Good timing! I see that you have some specialized bolts that push on fittings that are angled on the end to match the angle on the carriage shaft. I had been thinking along those same lines. Did you make those pieces or was that something you purchased? kiddwd says - Doc, I'm a new member to the forum. How do I navigate to the "Photos Section"? Own a 12" Atlas and would like to build a ball turner. Have a friend who would like a shifter ball turned for his hot rod. Thanks, Bill Kidd Jon Elson says - At the bottom of every message, this appears: > To see or edit your personal settings, view the photos, files or links > http://groups.yahoo.com/group/atlas_craftsman/ > Just click on this link, it takes you to the main page at Yahoo for > the group, there will be a number of links on the left edge to > see photos, files, links, database, etc. Jon William Abernathy says - From your photos, I can see how the fixed part is fastened to the knob on the cross-slide. I can't tell, however, how the part that holds the toolholder rotates on the aforementioned fixed piece. Howdya doodat? Bearing? Bushing? William swagrimreaper says - The metal started out as 3-1/2 in. x 1 inch 12L14 I bought off ebay. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rt=nc&nma=true&it em=270668666642&s\i=9qjrVTViMQZk9AMBvXYIi2vjiJ8%253D&vi ewitem=&sspagename=STRK%3AMEWNX%3AIT The actual bolts are carriage bolts I bought from home depot then I turned them down on the end and milled off the round head so all that was left was the flat part so it would fit the same square drive wrench for the atlas. I then made the angles plugs that the bolt presses up against the compound lug. The type of bolt is pictured in the link below: http://myword.info/images/ca_bolt_1a.jpg The lower part of the body clamps tight to the compound using the 2 bolts that press the 2 angled plugs up against the lug on the carriage. Then the top part of the body rotates on a precise machined ridge that keeps it rotating true around its axis. There is only a very small amount of contact between the two pieces to keep friction as low as possible. Even without grease it rotates very nice and smooth and solid. You can see in a couple of the pictures the ridge I machined to keep them centered together. The center bolt only holds the two pieces together and does NOT keep them centered. The bolt was machined so when it tightens up and shoulders out there is no play in the two halves. Once greased it rotates like a bearing using the thin film of grease that is forced under pressure between the two halves. Here is a link to my photobucket that has a couple more photo's in it. http://s30.photobucket.com/albums/c345/737mechanic/Projects/Ball%20Tur ner%20for%20Atlas%20Lathe/ ------- Re: Ball Turner for 10" atlas lathe repost Posted by: "William Mader" hillbrookx~xxwindstream.net Date: Fri Jan 7, 2011 9:45 am ((PST)) I keep looking at your photos and do not understand how you have it mounted on the cross slide. Can you help me? Would like to make one. Bill ------- Re: Ball Turner for 10" atlas lathe repost Posted by: "Scott Henion" shenionx~xxshdesigns.org Date: Fri Jan 7, 2011 9:54 am ((PST)) Here's mine: http://shdesigns.org/Craftsman-12x36/ballturn.shtml It is not mounted to the cross slide. You remove the cross slide and mount it on the same stud the cross slide or milling attachment mounts to. BTW, mine is simpler as it turns on the stud (one piece). Scott G. Henion Craftsman 12x36 lathe http://shdesigns.org/Craftsman12x36 ------- Re: Ball Turner for 10" atlas lathe repost Posted by: "William Mader" hillbrookx~xxwindstream.net Date: Fri Jan 7, 2011 10:26 am ((PST)) I guess my problem is I am using a South Bend lathe. The carriage is different. Bill ------- Re: Ball Turner for 10" atlas lathe repost Posted by: "Scott Henion" shenionx~xxshdesigns.org Date: Fri Jan 7, 2011 10:50 am ((PST)) Looks like the SB crosslide mounts in a similar way. You would remove the cross slide and make an adapter that fits over the pin. The cross slide can rotate, you are just making a cross slide that does not move and does not have all the stuff that gets in the way. ;) Here's one for either south Bend or Atlas from Google books: http://tinyurl.com/ball-turn Scott G. Henion Craftsman 12x36 lathe http://shdesigns.org/Craftsman12x36 ------- Re: Ball Turner for 10" atlas lathe repost Posted by: "swagrimreaper" swagrimreaperx~xxyahoo.com Date: Fri Jan 7, 2011 6:03 pm ((PST)) You first remove the compound by loosening the 2 hold down screws, then install the ball turner on the cross slide boss and tighten the 2 hold down screws on the ball turner base. Then the upper part of the ball turner will pivot freely around its axis. The operation is very smooth and easy and does not cause any chatter due to the fact the ball turner is mounted solidly to the cross slide. ------- Rounding stainless bolts [atlas_craftsman] Posted by: "JeffD" jefdaviesx~xxsbcglobal.net Date: Wed Jun 15, 2011 9:18 pm ((PDT)) HI Guys, No, I have not broken my lathe again. But Am still restoring my old race bike & wanna know if any of you has a good idea about Radiusing the top of my Stainless bolts. -- I am not talking about a big round, just a slight convex to make them show quality. Kindest regards, Jef ------- Re: Rounding stainless bolts Posted by: "JACK SIMS" jack-br549x~xxatt.net Date: Wed Jun 15, 2011 11:43 pm ((PDT)) You can always chuck them up in the lathe and do wonders with a file and some sandpaper, may sound crude but it works. Jack Sims Carrollton, Texas ------- Re: Rounding stainless bolts Posted by: "Cindy & Wayne Burner" burners4x~xxcomcast.net Date: Thu Jun 16, 2011 6:47 am ((PDT)) Jeff, there are plans in the photo pages on how to make a radius tool. Making useful items on the lathe, and for the lathe, is just as rewarding as working on motorcycles. I got my first Atlas, so that I could make parts for my bikes, that are no longer available (NLA). A lot of the parts for these old bikes are made out of a material I like to call "unobtainium". The radius tool is great at turning the ball end on handle cranks like are on our lathes. The sun is out here in NH today, maybe I will make some calls today, and see if any of my buddies want to take a ride to Laconia for some "eye candy". I am only 1.5 hrs away, and know all the twisty back roads to get there. Wayne(rice)Burner 10 x 54 Atlas with QC ------- Re: Rounding stainless bolts Posted by: "Doc" n8as1x~xxaol.com Date: Thu Jun 16, 2011 7:59 am ((PDT)) earliest metal turning was done w/"gravers'"..essentially wood turning chisels w/ steeper angles.......worn out files.... round, flat, teeth ground off, sharpened, held close to work on a rest (side of armstrong tool is useful), & applied as a scraping cut. DOES CUT STEEL ...very useful ...quick & no need for form tools & extensive set up, for many applications....CARE is required, as it is in wood turning. i have round, skew, 1/2 round, etc....at the ready. best wishes docn8as ------- Re: Rounding stainless bolts Posted by: "Ron Gerlach" r7734gx~xxhotmail.com Date: Thu Jun 16, 2011 9:56 am ((PDT)) Jeff: If you are in a hurry and do not want to take the time to build a radius tool, use your compound rest set to a handful, perhaps 5, different angles from 0 to 90 degrees to cut 5 facets that approximate a round surface; then use the files and sand paper suggested by others to do the final rounding and smoothing. The 5 or so angled cuts get you closer to a round surface so there is less filing. Just make sure you use oil on the sand paper and cover up the ways when you sand. The oil and the cover will keep the abrasive grit off the sliding way surfaces. RonG ------- Re: Rounding stainless bolts Posted by: "Ben D'Avanza" bendavanzax~xxgmail.com Date: Thu Jun 16, 2011 2:02 pm ((PDT)) I want to do the same thing. I usually just cut off the marks on the lathe and then finish on the belt sander, offering the bolt to the belt while chucked in a cordless drill, then progressively polish. It's not an exact method. The rounding sounds like a great look, much like the heads of bolts back in earlier times. The heads of many bolts don't leave much material left for rounding, it would have to be shallow. I need a radius tool, for sure. It's on my list of things to make or buy. Ben ------- Re: Rounding stainless bolts Posted by: "Joe R" jromasx~xxcolumbus.rr.com Date: Thu Jun 16, 2011 3:36 pm ((PDT)) Here's a radius cutter tool you can make using a QCTP boring bar holder. http://hobby-machinist.com/index.php?topic=1715.0 Joe R. ------- Parabolic Bowl Cutting Tool (like a Ball Cutter) [atlas_craftsman] Posted by: "Keith Mc" actix~xxPROVIDE.NET Date: Wed Jul 13, 2011 7:26 pm ((PDT)) [Moved from "Re: [atlas_craftsman] Re: Rounding stainless bolts"...] On Jul 9, 2011, James Walther wrote: > You like complicated? Go to You Tube and search "Radius Cutting Attachment Auto-feed" Everything's shop-made - radius cutting attachment and the power feed. < Just out of curiosity (after seeing that interesting auto-feed ball cutter tool). Has anyone EVER come up with a PARABOLIC cutting tool accessory for a lathe, like a Ball Cutter? (I'm new to this, so this may just be an ignorant question.) I'm interested in SOME day (no rush) trying to turn out a small solar focusing bowls on a lathe, for homemade solar concentrators. I was going to wait until I could CNC it, but this discussion made me curious about if it was possible to create a P-tool, like a Ball tool to do it better, with no "steps". If you can somehow make the lathe tool prescribe a parabola along ANY plane that includes the spin axis, the lathe headstock spins it into a parabolic bowl... The "Trammel of Archimedes" (aka ToA or "Do Nothing Machine") prescribes an ellipse, which is a basic conic section. See: ... http://en.wikipedia.org/wiki/Trammel_of_Archimedes ... http://cseligman.com/text/history/ellipses.htm Now it's been a LOOOONG time since I took Geometry, but isn't one end of an ellipse a decent approximation of Parabola? (It's obviously MUCH better than a circle! :-) If so, that MAY be good enough. Make a ToA like you would a Ball Cutter, and mount it to the cross-slide, with the long dovetail along the lathe X axis. Place a lathe cutting tool at the handle point such that it intersects the spin axis at the right height. Extend the other end of the bar out for one handle knob, and place another adjustable handle knob between the pivots. This gives you two hand control of the articulation. I'm imagining this assembly of a ToA: 1) Create the baseplate with two dovetail slots in it, to mount to the cross slide. 2) Create the Dovetail slides to run in them. 3) To set it, you'd create a pair of Yardstick Compass assemblies, like this: http://www.woodcraft.com/Images/products/06A51.jpg and attach them to the dovetail slides, such that they can spin. 4) Use a piece of bar stock with the tool mounted on the end of the stock at the right height. This allows you to dial in the focal length, and the inner diameter width as you wish. 5) Extend the linkage rod beyond the other side of the assembly. 6) To control it, create a second pair of Yardstick Compass assemblies FLIPPED OVER, to add handles above the bar that you can position and lock wherever they need to be to manage the cuts. Any way you do it, to use the tool you'd slowly advance the carriage toward the headstock, taking larger and larger "swipes", until you form your parabolic bowl. Questions: Does a tool like this already exist? (If so, what are they called and where would one find it?) If not, would the above work? Does this create the right shape? Is there a BETTER "simple machine", to proscribe a PURE parabola, like we do with Ball Turning Tools? Thanks! Keith Mc. ------- Re: Parabolic Bowl Cutting Tool (like a Ball Cutter) Posted by: "Dan Buchanan" db45acpx~xxyahoo.com Date: Wed Jul 13, 2011 8:18 pm ((PDT)) There are several great ideas out there for cutting spheres, balls and convex or cup shapes. Not very hard to make by some of the great plans I have seen in discussions in this group. Check the FILES area for plans available. If you have patience and a little extra dinero, look for something like a Holdridge Radii Cutter set. Here is their website link: http://www.holdridgemfg.com/ I picked up a Holdridge model 3D locally in practically unused condition, complete for just under $300.00. (Pardon the gloat.) It currently sells from tool houses for $1K or more. Cool factor alone is worth WHATEVER you can get it for, IMHO. It is an amazing tool and I am looking forward to setting it up and learning how to make it sing. Or whatever it is supposed to do. Dan ------- Re: Parabolic Bowl Cutting Tool (like a Ball Cutter) Posted by: "Keith Mc" actix~xxPROVIDE.NET Date: Thu Jul 14, 2011 1:19 am ((PDT)) Sorry Dan, but Ball (Radii) turning attachments makes spheres, not parabolas. (Please re-read my questions.) I'm familiar with those, and I'm sorry to say that they will not do what I wish. I don't see anything like what I seek in the FILES area, nor on the net. I've found macros for CNC lathes, but no geometrical tools (simple machines) to do it on a MANUAL lathe. I'm seeking a PARABOLIC cutter attachment for a MANUAL lathe, which may not even exist yet... Hence the questions. I'm also proposing a design for review and critique for an ELLIPTICAL cutter, which is at least a lot closer. (A "Trammel of Archimedes" [ToA] cutter mechanism.) Keith Mc. ------- Re: Parabolic Bowl Cutting Tool (like a Ball Cutter) Posted by: "Scott Henion" shenionx~xxshdesigns.org Date: Sat Jul 16, 2011 8:31 pm ((PDT)) Looks like a good application for metal spinning. Make a wood mold with the parabolic shape and form it aginst it. Would be quick and you could turn many out with little metal waste. Scott G. Henion Craftsman 12x36 lathe: http://shdesigns.org/Craftsman12x36 ------- Re: Parabolic Bowl Cutting Tool (like a Ball Cutter) Posted by: "James Walther" indianfourriderx~xxyahoo.com Date: Thu Jul 14, 2011 3:28 am ((PDT)) If the parabola needed is shallow enough, that is, if the focus point is close enough to the directrix, a section of an arc of a circle can be a very close approximation. My reflectors are .375 deep and 3.25 diameter, but I cut a radius of 2.6875 with the center offset .127 away from the operator. My reflectors focus the light from a 6-volt 1158 bulb into a 3" spot at a distance from the bulb of 12". I have fooled around with one outside in the sun, but the hole for the bulb messes a bit with the focus. I can send you a drawing showing the relationship of the arc to the parabola if you are interested. Regards, Jim ------- Re: Parabolic Bowl Cutting Tool (like a Ball Cutter) Posted by: "jerdalx~xxsbcglobal.net" jtiers Date: Thu Jul 14, 2011 5:01 am ((PDT)) It appears that actual thinking may be required for this...... Look at the definition of a parabola, which in one viewpoint is a conic section. It seems reasonable that a setup to trace that path on the surface of a cone would generate a parabola if a tool were made to follow the tracer, possibly with a pantograph arrangement for scaling. That actually would be fairly easy to set up, given a "model" cone that can be traced. Also, a parabola is a portion of the "limit case" of an ellipse as the distance between the foci goes to infinity, so there is an application for some type of ellipse generator. That should get you going. JT ------- Re: Parabolic Bowl Cutting Tool (like a Ball Cutter) Posted by: "anthrhodesx~xxaol.com" Date: Fri Jul 15, 2011 9:56 am ((PDT)) Looking at this post, I imagine this could be accomplished by turning a cone, then slicing it at the correct angle to get the desired parabola. Now take the piece and mount it to the lathe as a pattern and use a tracer attachment to control a cutting tool. A taper attachment could be adapted to use as a tracer. Just some thoughts. Anthony Berkeley, Calif. ------- Re: Parabolic Bowl Cutting Tool (like a Ball Cutter) Posted by: "William Rutiser" wruyahoo05x~xxcomcast.net Date: Thu Jul 14, 2011 6:20 am ((PDT)) Do google searches for parabola linkage parabola linkage machine Here are some relevant results: http://home.lightspeed.net/~jpaulk/geosketch/PARGENVS.HTM http://edwinsanimatedimages.com/parabola1.htm http://homepage.mac.com/dscher/foldedrect.html http://homepage.mac.com/dscher/schooten.html http://ecommons.cornell.edu/bitstream/1813/2718/1/2004-9.pdf http://www.utdallas.edu/~sxb027100/creu09/YatesParabola.html http://www.europa.com/~telscope/bldlp5.txt http://bbs.homeshopmachinist.net/showthread.php?t=48757 Bill ------- Re: Parabolic Bowl Cutting Tool (like a Ball Cutter) Posted by: "Bruce Freeman" freemab222x~xxgmail.com Date: Thu Jul 14, 2011 7:41 am ((PDT)) As somebody else has mentioned, a circle or ellipse can be used as an approximation to a parabola. The question is, how close to a parabola does one need? If this is to be a parabolic reflector for a spotlight, then the incandescent element is not a true point, so cannot be placed (only) at the focus. Hence, there's already built-in error, and a small additional error is of no consequence. One way to investigate this is to take a small flashlight bulb and place it at the "focus" of a "parabola" made from a flat plastic mirror (e.g., aluminized mylar). Monkey with the shape of the parabola (which really means its size, as all parabola are identical except for size) versus the position of the bulb versus the "tightness" of the resulting beam to get a feel for what's needed. Then translate this conclusion to a parabola of rotation. ------- Re: Parabolic Bowl Cutting Tool (like a Ball Cutter) Posted by: "Jon Elson" elsonx~xxpico-systems.com Date: Thu Jul 14, 2011 10:28 am ((PDT)) I did an ellipsoidal mirror years ago my Human-NC, ie. I wrote a program that computed the path and printed out a table, then I did it by hand. Ellipsoids are easy, you can do it with pins and a string. I assume there must be a similar scheme for doing parabolas. If so, a linkage with pivots and arms might be able to make the same path. But, if you are going to go to ALL THAT much trouble, I think a CNC conversion would actually be EASIER! Jon ------- NOTE TO FILE: There were a few more comments in this parabola conversation that you can find in the atlas_craftsman group archives. I suspect very few readers will need to make a parabolic item, but the thought processes of the group's members on this problem were interesting to read. ------- Re: tool post [atlas_craftsman] Posted by: "William Chamberlain" losthelm1x~xxyahoo.com Date: Fri Sep 2, 2011 7:08 am ((PDT)) I actually found a basic radius turner through YouTube. http://www.youtube.com/watch?v=tbvOb-tTNyc&feature=related http://bedair.org/Ball/ball.html and a mesage board with that paticular design mod. http://madmodder.net/index.php?topic=319.0 There are a few half finished projects on Ebay. Why buy when you can make your own. Hope this helps Bill ------- Ball turner [atlas_craftsman] Posted by: "recycalem" grandmasterjx~xxearthlink.net Date: Wed Oct 12, 2011 8:37 am ((PDT)) I stumbled upon Steve Bedair's site with PDF drawings of ball turner by Burt Rosensweig. Looked interesting so with some mounting base changes I made one. It works great!!! even got my 12 year old son interested, even better! Have pics posted under "Jims follower rest" notice also the 1 inch adapter for 10" follower rest to be used on a 12" craftsman. It's nice that people host sites with great projects. Has anyone else made the ball turner? I would like to see them. Jim -------