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View Full Version : Using a 5C collet chuck with a South Bend 10K Lathe



mikem
12-13-2010, 02:09 PM
Can I use a 5C collet chuck like the one that little machine Shop advertises in the HSM magazine with my South Bend 10K lathe? There are back plates with the 1.5 inch 8 TPI mount that I need.

I have some collets that will hold discs but they would need to be fastend from the back using a closer. Do the collet chucks that will work with my SB hold the collet in with a nut from the front rather than a closer that tightens from the back through the spindle center hole?

The collets that I have can't be clamped in from the front becasue they are made to hold discs that are larger in diameter than the collet.

Thanks---MIke.

lynnl
12-13-2010, 02:45 PM
I haven't had a chance to examine one of those Little Machine Shop 5C collet chucks firsthand, but I'm pretty sure there's a pinion that is geared to a nut in the back of the chuck, that encircles and engages the external threads of the collets and pulls them in.

Here's a description of a 5C chuck designed by a Pat Loop, which is probably a forerunner of the LMS design. This will show how the nut functions. Although this nut is not geared to a pinion, but rather just accessed directly through openings in the chuck body.
http://www.metalworking.com/DropBox/collet_chuck.pdf

Or a better picture can be seen here in the 4th post from the top.
http://www.practicalmachinist.com/vb/south-bend-lathes/mla-loop-style-collet-chuck-195959/

mikem
12-13-2010, 04:13 PM
Thanks for the link. I never thought of the possibility of a nut from the back that was accessible from the side. I will look into getting one. Any one have the Little Machine Shop or the CDCO one? Do you like it?

oldtiffie
12-13-2010, 04:36 PM
I'd wait a while yet.

There was a thread here recently (can't find it) about a flange/face-mounted C5 collet adaptor that was very similar to the item that LMS has.

The particular C5 adaptor had terrible problems with the internal ball-type thrust race as the races were in bad shape and the cage was badly broken and the balls were very poor (or some missing?).

I can't recall if it was a LMS product or not - I think not - but in the unlikely event that you got that item from LMS, they would make it good.

I "searched" for that thread but could not find it.

Perhaps someone else can recall it or post a link to it.

I have the ER-32 collet adaptor from LMS, and it, like just about all the stuff I've got from LMS and CDCO (USA) was excellent.

Paul Alciatore
12-13-2010, 04:40 PM
Their model 3047 5C collet chuck appears to be of the variety that uses a key which is shown in their photo to turn an internal, threaded nut that is used to close the collet. The collet screws into this nut and there is probably a bevel gear arrangement to turn it from the key which is inserted in the hole(s) that are visible on the outside of the chuck.

This arrangement is needed on a machine like the SB9 or SB10 because the spindle's through hole is smaller than the diameter at the rear of the 5C collets and a simple closer tube would not fit through it. With this chuck you should be able to close the collet even if the chuck in not mounted on the lathe. For best accuracy, you will need a back plate (adapter) on which the mounting surface is machined (by you) on your lathe to precisely match the collet chuck's rear mounting surface.

Other choices for the SBs would be to purchase 3MT collets and make a tube style closer for them.

I have an SB9 and an old three jaw scroll chuck that I plan to convert to a 5C collet chuck. It will function much the same as the one shown in the Little Machine Shop ads. One advantage of this type of collet chuck on a small spindle machine is that it allows you to take full advantage of the spindle's through hole size as no tube or rod needs to pass through it. I plan to make mine to do so but I can not speak as to any limitation that the advertised one may have.

Carld
12-13-2010, 04:43 PM
I too have considered buying a collet chuck from CDCO and am interested in others opinions if they have one.

One thing for sure, I would tear it down and inspect it and repair/modify as needed.

mikem
12-13-2010, 04:59 PM
I have a set of 6K collets that fit my 10K South Bend but the 5C collets would let me use the disc mounting collets that I got off of eBay in job lot of stuff. Also the collet closer for my 6K collets is hard to use since the left side of my lathe is up against a tool cart that has to be moved every time to put it in and out. Thanks--Mike.

Arthur.Marks
12-13-2010, 05:00 PM
Just a note on the collet chucks that use a scroll to pull the collet it. It takes _for_ev_er_ to pull a collet all the way in. Perhaps you could use a collet wrench to get it most of the way on faster? I mean the wrenches with three thin fingers which engage the slots on the collet face. I had one from LatheMaster and the collet seat spec was fine, but I hated turning that chuck key for "hours" (poetic license applies :)) to seat the 5C. BTW, LatheMaster sells a different brand now, so don't take my comments as indicative of that specific one.

rohart
12-13-2010, 06:44 PM
Arthur - thanks. I've just got hold of a machine that has the D1-3 camlock on its spindle, and I've been looking at chucks for %C collets, and wondering what the recesses on the side were for.

What I want is an adapter that lets me use a drawbar. I guess I'll just get turning and make my own adapter for the spindle's MT4 internal taper.

I'm not sure, but I think you just saved me from a costly error.

I take it the OP's spindle is too narrow to let a 5C fit in it. I know he has some collets already, but the 3C series is nice too, and a lot narrower. Ah - just the tool cart business. Maybe time for a bit of shop rearrangement - a new gap in the tool cart at just the right height ? Moving a (movable ?) tool cart seems a piece of cake compared to some of the shenanigans I have to go through when i want to use a machine that's been boxed in by later developments. To get at my compressor right now I would have to shift a motorcycle and a pedestal drill !

Arthur.Marks
12-13-2010, 06:57 PM
rohart- you may want to look into the MLA kit: Collet Chuck (MLA-21) (http://www.sc-c.com/metallathe/MLA21.html) It avoids the problem I mentioned above. You'll need at least a 4-1/2 MT spindle to use a 5C spindle adapter. 4MT is slightly too small, IIRC.

Paul Alciatore
12-13-2010, 10:22 PM
Just a note on the collet chucks that use a scroll to pull the collet it. It takes _for_ev_er_ to pull a collet all the way in. Perhaps you could use a collet wrench to get it most of the way on faster? I mean the wrenches with three thin fingers which engage the slots on the collet face. I had one from LatheMaster and the collet seat spec was fine, but I hated turning that chuck key for "hours" (poetic license applies :)) to seat the 5C. BTW, LatheMaster sells a different brand now, so don't take my comments as indicative of that specific one.

I thought of that even though my intended design does not use the actual scroll. I plan to purchase an inexpensive recharagable drill or screwdriver and put a tool on it that matches the chuck wrench. High speed to almost get it tight and then manual wrench to finish. If you are making a series of identical parts, you only need to loosen the collet enough to remove one and insert the next so the power tool will not be needed most of the time.

mikem
12-13-2010, 10:55 PM
I ordered the CDCO collet chuck today. They claim to have .0004 TIR. Will post back when it comes in and let you know what it is like. Thanks--Mike.

Arthur.Marks
12-14-2010, 12:09 AM
If you are making a series of identical parts, you only need to loosen the collet enough to remove one and insert the next so the power tool will not be needed most of the time.

Agreed. That is where they shine.

Stepside
12-14-2010, 10:28 AM
I have a SB9 with a 5C collet chuck. I bought my chuck almost 10 years ago from New England Brass. It is a Bison product. Heres what I know 1) It is as accurate as my Royal collets made in England. 2) It is slow to change collets. About as slow as changing collets that use a drawbar. 3) I use it for pot chuck collets as well as standard collets. 4) you cannot wind the collet in with a tool that spins the collet. There is a drive pin that prevents the collet from spinning in the chuck. 5) I know I spent more money than the LMS or CDKO chucks being discussed. When I bought mine the Bison brand were the only game in town. 6) If you are winding in and out a bunch when doing multiples of the same part you probably have the wrong sized collet. I can release or tighten a part with at most two turns of the T-handle chuck wrench.

So use the "slow winding time" to think about the task at hand and the secquence of operations. Not a bad use of time.

Spandau
12-14-2010, 02:36 PM
I use a Hardinge/Sjogren 5C 'Speed Chuck' on a SB9C, and I find it quite handy. I can use the forward/stop/reverse switch to quickly seat the collet, and then it only requires a 1/4 turn or so of the handwheel to loosen/tighten the collet to remove the work.

topct
12-14-2010, 04:56 PM
I use a Hardinge/Sjogren 5C 'Speed Chuck' on a SB9C, and I find it quite handy. I can use the forward/stop/reverse switch to quickly seat the collet, and then it only requires a 1/4 turn or so of the handwheel to loosen/tighten the collet to remove the work.


http://www.hardinge.com/usr/pdf/collet/B123_Sjogren.pdf

rohart
12-14-2010, 07:55 PM
Thanks Arthur. And about the 4 1/2, you're spot on.

My plans have migrated to making an adaptor to use my collection of 20mm Lorch collets. A simpler task altogether.

I'm gearing myself up to making D1-3 fitments, but not yet.