3C vs 6K
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David Rysdam <david@...>
For my decoder ring project, I think I want to use a pot collet (why are
they called that?) to clean up the back sides after parting. But I don't want to chase down and pay for a 6K one. In the mailing list archives, I find claims that the 10K spindle can take a 3C collet, although you need a different closer because of non-matching threads. (Online I've found claims that the collets are totally different, but I guess I can trust the SB mailing list over some guy on PM.) However, I have the speed closer and I'd prefer not to give that up. Is there an easy way to non-destructively modify that to be both 3C and 6K? Can just the tube be replaced? This would be especially nice if I do a mini-run of ~5 pairs of rings, which would be 30 pieces of similar diameters. Wouldn't have to crank the handwheel all those times for each piece...
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Thomas G Brandl
Dave,
They are different. The two main differences are the threads and the front angle. I am guessing you have a 3C collet or 3C Pot collet. I do not know the size 'OD' of these rings. There are also soft collets or 'Emergency' collets. Not sure of the availability of these in 3C or 6K. I could see that you could adapt a 3C collet or even a 3C pot collet to work. The 1K spindle would take the 3C SB adapter. Not sure of the thru hole though. Then you could make a sleeve threads ID and OD. ID for 3C threads, and OD for 6K threads. That is if you have a 6K closer. If a pot collet, then you could make a closer ring for it. Thread it onto the spindle, the cut an angle counter to the angle on the pot collet. On PM, in the Monarch section on guy did this. Not easy finding Monarch stuff. I do have one for my 10EE, but don't have the complete lever closer set up. Tom From: David Rysdam <david@...> To: SOUTHBENDLATHE@... Date: 04/01/2014 01:49 PM Subject: [SOUTHBENDLATHE] 3C vs 6K Sent by: SOUTHBENDLATHE@... For my decoder ring project, I think I want to use a pot
collet (why are
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vtsblogan@...
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Jim B. <btdtrf@...>
I have a 10K spindle in my 9” Workshop headstock.
I do use 6K/3C/3AT collets. I do not have a speed closer. I do have 3 handwheel closers. The 3C and the 3AT have essentially the same threads but the 3AT is shorter, a bit larger in diameter and has a different taper than the 3C. I have two POT collets for 3C.
I see no reason you could not make a tube for the 3C to fit your speed closer. You would need a taper adapter sleeve for your lathe, to take 3C if you do not have one and a Nose piece if you do not have one
Now a once in a lifetime offer.
I have a brand new 6K pot collet. Never used. It’s a big one, 4-1/2 OD. I will probably never use it. I have had it since about the time SB had their going out of business sale. I would be willing to part with it. I am getting old and need to start clearing stuff out. Not inexpensive but if you are interested contact me off line.
I also have 3 6K SOFT steel collets; a 1/8 a ½, and a 9/16” (9/16 could be 35/64. All are unmarked. They say Modern, 6K, soft.
I think you could just turn a shallow 1” ring in them. The OD seems to be 1-3/16 (1.178), the key is 0.080 deep. The ring might break through the key.
Perhaps one of these would do better; I would guess the 9/16 one could work. These would be cheaper.
Jim B.
From: SOUTHBENDLATHE@... [mailto:SOUTHBENDLATHE@...] On Behalf Of David Rysdam
Sent: Tuesday, April 01, 2014 1:52 PM To: SOUTHBENDLATHE@... Subject: [SOUTHBENDLATHE] 3C vs 6K
For my
decoder ring project, I think I want to use a pot collet (why are
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kaleb sells
Can a 10k spindle be used in any 9" workshop? Does it give youba bigger through-hole? Kaleb Sells
On Apr 1, 2014 2:08 PM, "Jim B." <btdtrf@...> wrote:
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Jim B. <btdtrf@...>
As I noted I have one in my 9”Workshop. The normal 9” Workshop spindle is 49/64 bore through. The 10K is 55/64 through hole.
Jim B.
From: SOUTHBENDLATHE@... [mailto:SOUTHBENDLATHE@...] On Behalf Of kaleb sells
Sent: Tuesday, April 01, 2014 3:39 PM To: SOUTHBENDLATHE@... Subject: RE: [SOUTHBENDLATHE] 3C vs 6K
Can a 10k spindle be used in any 9" workshop? Does it give youba bigger through-hole? Kaleb
Sells On Apr 1, 2014 2:08 PM, "Jim B." <btdtrf@...> wrote:
I have a 10K spindle in my 9” Workshop headstock.
I do use 6K/3C/3AT collets. I do not have a speed closer. I do have 3 handwheel closers. The 3C and the 3AT have essentially the same threads but the 3AT is shorter, a bit larger in diameter and has a different taper than the 3C. I have two POT collets for 3C.
I see no reason you could not make a tube for the 3C to fit your speed closer. You would need a taper adapter sleeve for your lathe, to take 3C if you do not have one and a Nose piece if you do not have one
Now a once in a lifetime offer.
I have a brand new 6K pot collet. Never used. It’s a big one, 4-1/2 OD. I will probably never use it. I have had it since about the time SB had their going out of business sale. I would be willing to part with it. I am getting old and need to start clearing stuff out. Not inexpensive but if you are interested contact me off line.
I also have 3 6K SOFT steel collets; a 1/8 a ½, and a 9/16” (9/16 could be 35/64. All are unmarked. They say Modern, 6K, soft.
I think you could just turn a shallow 1” ring in them. The OD seems to be 1-3/16 (1.178), the key is 0.080 deep. The ring might break through the key.
Perhaps one of these would do better; I would guess the 9/16 one could work. These would be cheaper.
Jim B. From: SOUTHBENDLATHE@... [mailto:SOUTHBENDLATHE@...]
On Behalf Of David Rysdam
For my
decoder ring project, I think I want to use a pot collet (why are
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David Rysdam <david@...>
"Jim B. " <btdtrf@...> writes:
You would need a taper adapter sleeve for your lathe, to take 3C ifYour offer of the 6K tooling is kind, but I would never be able to bring myself to alter something that isn't being made anymore. I see a taper adapter sleeve here: http://littlemachineshop.com/products/product_view.php?ProductID=2240&category= Looks a little pricey for something that would only take a couple hours to make. Of course, the accuracy would be far less, but then I don't need phenomonal accuracy. I just need something better than the 3 jaw is giving me when I clean up the backs of the rings. As for the nose piece--do you mean one that is different from the spindle nose piece I already use with the few 6K collets I have? Something specially shaped to the pot collet "head"?
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David Rysdam <david@...>
David Rysdam <david@...> writes:
Looks a little pricey for something that would only take a couple hoursOh, looks like this pair would be cheaper: http://www.tools4cheap.net/proddetail.php?prod=3atnose http://www.tools4cheap.net/proddetail.php?prod=3at3pot Even if I never use the adapter for anything but that collet, it's still cheaper than just the 3C adapter. I don't see any new 3AT collets being sold anywhere, so that's a real possibility.
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sblatheman
I have N.O.S. and used 3c collet sleeves for less Send me an email. Ted
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Jim B. <btdtrf@...>
I agree but these are designed to be altered. You have already found the ones at tools4cheap. There are some larger collets that do require a backing plate. You do have to be careful.
Jim B.
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Gregg Eshelman
On 4/1/2014 6:04 PM, David Rysdam wrote:
"Jim B. " <btdtrf@...> writes:Something like this perhaps?You would need a taper adapter sleeve for your lathe, to take 3C ifYour offer of the 6K tooling is kind, but I would never be able to bring https://www.flickr.com/photos/27748767@N08/11807014954/in/set-72157639469853874 That setup came with a 10" Montgomery Ward/Logan. Should fit any lathe with an MT3 spindle taper and the standard thread for such spindles. The "chuck" screws on, then a collet is inserted into the adapter and slit into the chuck. Last, the external ring is screwed on. It's a solid setup, seems like it would be quite accurate. It appears to be shop made, can't find any collets like them, slightly larger than the 3C or 3AT. No threads on the collets, they're held by the external ring. The largest ID I measure (at the back end) on the collets I have for it is 0.622" (a skosh under 5/8"), that's larger than the 1/2" any 3C or 3AT can possibly hold if bored to maximum ID. I'm willing to loan the set to someone to make detailed drawings and/or to setup for a production run. Should work with any MT3 spindle and by a simple thread change on the chuck, with other spindle threads. The design would scale up to MT4 and similar size proprietary tapers to enable stuffing the largest possible workpiece into a collet in the spindle without a bulky chuck with lots of overhang. The lathe was at one time owned by the Consolidated Vacuum Co. of Rochester, NY. Likely bought new by CVC in 1941. CVC did some work for NASA, never know but the lathe may have turned parts that went into some of the early rockets.
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David Rysdam <david@...>
David Rysdam <david@...> writes:
For my decoder ring project, I think I want to use a pot collet (why areThanks for all the help, everyone. I think I probably do eventually want to build up a 3C system because of the wider availability of collets, but the startup cost for this project is too high. Instead, I'm thinking about making my own 6K(ish) "soft collet" in Al. In this PM thread: http://www.practicalmachinist.com/vb/south-bend-lathes/collets-195569/ there are some dimensions, but I think the only vital ones are the thread and the head angle. I think even the angle could be approximate if there's no danger of damaging the spindle and it provides even pressure all the way around. Then I can use my existing lever closer, don't need an adapter, etc. I've made similar collet-like things before, but gripped them in the 3 jaw. The repeatability wasn't there. This would fix that. Could also make a 3 jaw version but mark where the jaws go--would save a chuck change. I just now realized that the other reason my collet-like things didn't work so well was that I cross-cut them into 4 sections but then tried to squeeze them with 3 jaws. Uneven pressure.
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