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I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117
head. It needs to be hard so I'll make it out of a 7/64 drill bit, the size of the head. What's a clever way to hold this in the lathe? it would be hard to make soft jaws go down this small. I'm thinking some sort of collapsible bushing that I'd drill. Karl |
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Karl Townsend wrote:
I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117 head. It needs to be hard so I'll make it out of a 7/64 drill bit, the size of the head. What's a clever way to hold this in the lathe? it would be hard to make soft jaws go down this small. I'm thinking some sort of collapsible bushing that I'd drill. Karl How about drilling a hole in a piece of round stock with the 7/64 bit. Then gluing the bit in the hole. Mount the piece of round stock in the chuck and go to work. -- Steve W. |
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On 2/23/2012 9:54 PM, Karl Townsend wrote:
I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117 head. It needs to be hard so I'll make it out of a 7/64 drill bit, the size of the head. What's a clever way to hold this in the lathe? it would be hard to make soft jaws go down this small. I'm thinking some sort of collapsible bushing that I'd drill. Karl A split sleeve - something like a collet? |
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Richard wrote: On 2/23/2012 9:54 PM, Karl Townsend wrote: I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117 head. It needs to be hard so I'll make it out of a 7/64 drill bit, the size of the head. What's a clever way to hold this in the lathe? it would be hard to make soft jaws go down this small. I'm thinking some sort of collapsible bushing that I'd drill. Karl A split sleeve - something like a collet? Like one from a Dremmel tool? -- You can't have a sense of humor, if you have no sense. |
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On 2/23/2012 8:18 PM, Richard wrote:
On 2/23/2012 9:54 PM, Karl Townsend wrote: I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117 head. It needs to be hard so I'll make it out of a 7/64 drill bit, the size of the head. What's a clever way to hold this in the lathe? it would be hard to make soft jaws go down this small. I'm thinking some sort of collapsible bushing that I'd drill. Karl A split sleeve - something like a collet? Once you get it made, how do you harden it without burning it up? Paul |
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On 2012-02-24, Karl Townsend wrote:
I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117 head. It needs to be hard so I'll make it out of a 7/64 drill bit, the size of the head. What's a clever way to hold this in the lathe? it would be hard to make soft jaws go down this small. I'm thinking some sort of collapsible bushing that I'd drill. Can you use 5C collets? If so, consider getting an "emergency" collet, soft, which can be drilled/bored to size. Or -- if you have a small enough lathe with a Watchmaker's spindle, you should be able to find a WW series collet of just the right size. For the 0.109 (if that is the diameter), a #27 or #28 collet (they are marked in tenths of mm). For the 0.117 (if *that* is the diameter, you would need a #30 likely, or perhaps a #29. (It calculates out as 2.9718mm FWIW. The WW collets are one of my reasons for holding on to both my Unimat SL-1000 (with the watchmaker's spindle), and the Taig (with a similar but less versatile spindle). Good Luck, DoN. -- Remove oil spill source from e-mail Email: | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
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Paul Drahn fired this volley in news:ji74af$glc$2
@dont-email.me: Once you get it made, how do you harden it without burning it up? Paul Wrap it in stainless steel heat treating wrapping foil first. And start the process in a carburizing atmosphere. LLoyd |
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Wind some wire around it to build up the diameter. On Thu, 23 Feb 2012 21:54:33 -0600, Karl Townsend wrote: I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117 head. It needs to be hard so I'll make it out of a 7/64 drill bit, the size of the head. What's a clever way to hold this in the lathe? it would be hard to make soft jaws go down this small. I'm thinking some sort of collapsible bushing that I'd drill. Karl Regards, Boris Mohar Got Knock? - see: Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca void _-void-_ in the obvious place |
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On Feb 23, 7:54*pm, Karl Townsend
wrote: I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117 head. It needs to be hard so I'll make it out of a 7/64 drill bit, the size of the head. What's a clever way to hold this in the lathe? it would be hard to make soft jaws go down this small. I'm thinking some sort of collapsible bushing that I'd drill. Karl Seems simple for a smart guy like Karl so I must be missing something but here goes anywar: I would make it like this Chuck up a piece of 0.25 drill rod (O-1) in the late 3 jaw chuck with 1/2 inch extending out Cut the diameter to 0.109 by 0.357 long Cut down to 0.096 by 0.25 long It is going to spring a little so use light cuts to finsh it off Part it off Heat treat by placing it on an SS plate and heat from the bottom I made several pins this way with even smaller diameters |
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On Thu, 23 Feb 2012 21:54:33 -0600, Karl Townsend
wrote: I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117 head. It needs to be hard so I'll make it out of a 7/64 drill bit, the size of the head. What's a clever way to hold this in the lathe? it would be hard to make soft jaws go down this small. I'm thinking some sort of collapsible bushing that I'd drill. Karl What am I missing? Why not a 7/64 collet? -- Ned Simmons |
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On Feb 23, 8:54*pm, Karl Townsend
wrote: I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117 head. It needs to be hard so I'll make it out of a 7/64 drill bit, the size of the head. What's a clever way to hold this in the lathe? it would be hard to make soft jaws go down this small. I'm thinking some sort of collapsible bushing that I'd drill. Karl They do make pin vises for such things, chuck it up in that, then center it up in the 4 jaw. And drill shanks are soft and you'll have a hard time hardening it if the bit is HSS. Go get a piece of drill rod the right size, the good stuff comes with heat treatment instructions so you can get the proper hardness. You could almost chuck the thing in an electric drill and reduce the size with a file. There's not that much to take off. Make two while you're at it. Stan |
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"Karl Townsend" wrote in message ... I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117 head. It needs to be hard so I'll make it out of a 7/64 drill bit, the size of the head. What's a clever way to hold this in the lathe? it would be hard to make soft jaws go down this small. I'm thinking some sort of collapsible bushing that I'd drill. Karl Stick it in a drill chuck. You could grab the drill chuck in the lathe chuck or maybe fit the tailstock chuck to the spindle with a live-center sleeve. Jacobs ball-bearings chucks work pretty well on a lathe spindle. I leave a 1/2" 33B on my 6" lathe and have a 58B on the indexer, and made an adapter to fit it to the South Bend. http://www.armurerieduroi.com/pages/...ck_jacobs.html http://www.practicalmachinist.com/vb...img_6732-2.jpg In one of their pamphlets SB says the chuck was meant for refinishing automotive valves and shouldn't be used for heavy turning. jsw |
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"Karl Townsend" wrote in message ... I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117 head. It needs to be hard so I'll make it out of a 7/64 drill bit, the size of the head. What's a clever way to hold this in the lathe? it would be hard to make soft jaws go down this small. I'm thinking some sort of collapsible bushing that I'd drill. Karl You made me curious so I went down to check. 1/8" music wire in a 5C collet cuts easily with HSS, ground to a sharp point to make a square shoulder. jsw |
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On Fri, 24 Feb 2012 06:36:53 -0800 (PST), toolbreaker
wrote: On Feb 23, 7:54*pm, Karl Townsend wrote: I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117 head. It needs to be hard so I'll make it out of a 7/64 drill bit, the size of the head. What's a clever way to hold this in the lathe? it would be hard to make soft jaws go down this small. I'm thinking some sort of collapsible bushing that I'd drill. Karl Seems simple for a smart guy like Karl so I must be missing something but here goes anywar: I would make it like this Chuck up a piece of 0.25 drill rod (O-1) in the late 3 jaw chuck with 1/2 inch extending out Cut the diameter to 0.109 by 0.357 long Cut down to 0.096 by 0.25 long It is going to spring a little so use light cuts to finsh it off Part it off Heat treat by placing it on an SS plate and heat from the bottom I made several pins this way with even smaller diameters Doh! This is how I did it. Sometimes i have a brain fart. I've got 2J collets for my 10EE but not many real small ones. Karl |
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On 24 Feb 2012 05:31:07 GMT, "DoN. Nichols"
wrote: On 2012-02-24, Karl Townsend wrote: I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117 head. It needs to be hard so I'll make it out of a 7/64 drill bit, the size of the head. What's a clever way to hold this in the lathe? it would be hard to make soft jaws go down this small. I'm thinking some sort of collapsible bushing that I'd drill. Can you use 5C collets? If so, consider getting an "emergency" collet, soft, which can be drilled/bored to size. Or -- if you have a small enough lathe with a Watchmaker's spindle, you should be able to find a WW series collet of just the right size. For the 0.109 (if that is the diameter), a #27 or #28 collet (they are marked in tenths of mm). For the 0.117 (if *that* is the diameter, you would need a #30 likely, or perhaps a #29. (It calculates out as 2.9718mm FWIW. The WW collets are one of my reasons for holding on to both my Unimat SL-1000 (with the watchmaker's spindle), and the Taig (with a similar but less versatile spindle). Good Luck, DoN. Mabee something like a pin vise? |
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On 2012-02-24, Paul Drahn wrote:
On 2/23/2012 8:18 PM, Richard wrote: On 2/23/2012 9:54 PM, Karl Townsend wrote: I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117 head. It needs to be hard so I'll make it out of a 7/64 drill bit, the size of the head. Note that most drill bits have a soft shank and a HSS blade, so the shank won't do much for you. I don't think that it has enough carbon to harden well at all. (If you only need the surface hardened, you can get some Kasenite or other case hardening pack material for heat treating it. Good Luck, DoN. -- Remove oil spill source from e-mail Email: | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
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On 25 Feb 2012 05:55:43 GMT, "DoN. Nichols"
wrote: On 2012-02-24, Paul Drahn wrote: On 2/23/2012 8:18 PM, Richard wrote: On 2/23/2012 9:54 PM, Karl Townsend wrote: I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117 head. It needs to be hard so I'll make it out of a 7/64 drill bit, the size of the head. Note that most drill bits have a soft shank and a HSS blade, so the shank won't do much for you. I don't think that it has enough carbon to harden well at all. (If you only need the surface hardened, you can get some Kasenite or other case hardening pack material for heat treating it. Don't case-harden HSS. The shank has plenty of carbon -- and chromium, and probably molybdenum, to harden it up to over Rc 60. However, it's not a good idea to do so. There are too many other things going on with HSS alloys; you risk winding up with a weak part unless you have good temperature control. Note that a heat-and-quench hardening will harden HSS, but it won't make it "high-speed." HSS requires a two-stage heat treatment in order to develop red hardness, and the second stage is a solution/precipitation hardening that is a real challenge in a home shop. It can be done, but you have to know what alloy you're dealing with and you have to know just what you're doing. You also need *very* good temperature control. Music wire or oil-hardening drill rod would be much preferred. They can be easily and reliably hardened and tempered. -- Ed Huntress Good Luck, DoN. |
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On 2012-02-25, Ed Huntress wrote:
On 25 Feb 2012 05:55:43 GMT, "DoN. Nichols" wrote: On 2012-02-24, Paul Drahn wrote: On 2/23/2012 8:18 PM, Richard wrote: On 2/23/2012 9:54 PM, Karl Townsend wrote: I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117 head. It needs to be hard so I'll make it out of a 7/64 drill bit, the size of the head. Note that most drill bits have a soft shank and a HSS blade, so the shank won't do much for you. I don't think that it has enough carbon to harden well at all. (If you only need the surface hardened, you can get some Kasenite or other case hardening pack material for heat treating it. Don't case-harden HSS. The shank has plenty of carbon -- and chromium, and probably molybdenum, to harden it up to over Rc 60. Are you saying that the shank of a typical drill bit is also HSS? I've always understood them to be mild steel welded to the HSS which implements the flutes and other cutting surfaces. I was assuming that if he used the shank, and had to harden it, it would be mild steel, not HSS, so I was not advising case-hardening HSS. However, it's not a good idea to do so. There are too many other things going on with HSS alloys; you risk winding up with a weak part unless you have good temperature control. And it is likely that *if* the shank is really HSS, you won't be able to machine it anyway, unless with a toolpost grinder. :-) Note that a heat-and-quench hardening will harden HSS, but it won't make it "high-speed." HSS requires a two-stage heat treatment in order to develop red hardness, and the second stage is a solution/precipitation hardening that is a real challenge in a home shop. It can be done, but you have to know what alloy you're dealing with and you have to know just what you're doing. You also need *very* good temperature control. Not at all what I was advising. Music wire or oil-hardening drill rod would be much preferred. They can be easily and reliably hardened and tempered. Agreed. Much better choices than old drill bit shanks. Enjoy, DoN. -- Remove oil spill source from e-mail Email: | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
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On 26 Feb 2012 05:06:28 GMT, "DoN. Nichols"
wrote: On 2012-02-25, Ed Huntress wrote: On 25 Feb 2012 05:55:43 GMT, "DoN. Nichols" wrote: On 2012-02-24, Paul Drahn wrote: On 2/23/2012 8:18 PM, Richard wrote: On 2/23/2012 9:54 PM, Karl Townsend wrote: I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117 head. It needs to be hard so I'll make it out of a 7/64 drill bit, the size of the head. Note that most drill bits have a soft shank and a HSS blade, so the shank won't do much for you. I don't think that it has enough carbon to harden well at all. (If you only need the surface hardened, you can get some Kasenite or other case hardening pack material for heat treating it. Don't case-harden HSS. The shank has plenty of carbon -- and chromium, and probably molybdenum, to harden it up to over Rc 60. Are you saying that the shank of a typical drill bit is also HSS? Yes. I've always understood them to be mild steel welded to the HSS which implements the flutes and other cutting surfaces. I've never heard that. As far as I know, they just partially anneal the shank, or maybe they don't quench the shank in the initial heat-and-quench. I was assuming that if he used the shank, and had to harden it, it would be mild steel, not HSS, so I was not advising case-hardening HSS. However, it's not a good idea to do so. There are too many other things going on with HSS alloys; you risk winding up with a weak part unless you have good temperature control. And it is likely that *if* the shank is really HSS, you won't be able to machine it anyway, unless with a toolpost grinder. :-) You can mill and turn annealed HSS. I've done it in my SB lathe, with HSS lathe bits. That is, assuming the shanks of HSS drill bits are HSS. g I'm pretty sure they are, Don. I've never heard of them being welded. I would think that would be an expensive way to make a dtill bit. Before we leave this, we should point out that most grades of HSS have *very* high carbon content -- 0.80% to 1.1%. That's up there in the range of music wire and antique straight razors. You won't increase hardenability by treating them with Kasenit. They already have all the carbon they can use for hardening. The problem with heat-treating HSS is that the alloy constituents that form carbides (there are several) have to be heated just right or you get variable results when they either 1) got back into solution or 2) form free carbides. Without excellent temperature control and timing, including temperature ramping and soaking, you get unknowable results, with a strong possibility you will make the material brittle and weak. So it's not a material to heat-and-quench with a torch, unless you're willing to experiment. -- Ed Huntress Note that a heat-and-quench hardening will harden HSS, but it won't make it "high-speed." HSS requires a two-stage heat treatment in order to develop red hardness, and the second stage is a solution/precipitation hardening that is a real challenge in a home shop. It can be done, but you have to know what alloy you're dealing with and you have to know just what you're doing. You also need *very* good temperature control. Not at all what I was advising. Music wire or oil-hardening drill rod would be much preferred. They can be easily and reliably hardened and tempered. Agreed. Much better choices than old drill bit shanks. Enjoy, DoN. |
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