Collets for a non-5C lathe: R8 and other sundry alternatives

Anyone made a 5C collet chuck?

Metal Lathe Accessories has a 5C collet kit which is adaptable to almost anything from 1-1/2-8 to 2-1/4-8.

I use a Hardinge-Sjogren, purchased on eBay.

An incredibly stupid design move on the part of Powermatic/Houdaille. This lathe *IS* an 11" lathe with a different spindle, see below.

I would not recommend this. Diminished through capacity, and R-8 collets are "sprung" undersized (or should be). This is so they will tend to hold the tool (they are designed for Bridgeport vertical mills and similar) when released, so your end mill doesn't drop to the table. OTOH, workholding collets, such as 5-C, 3-C, 3-AT etc, are sprung oversized. When released, they will tend to spring to an oversized condition, allowing easier stock change or movement.

And I don't think you are likely to find square or hex shaped R-8 Collets.

We carry these. See

I would not recommend this course of action.

Actually, consider just replacing the spindle itself. I have not done it myself, but I have talked to people who have changed out the spindle from a 10" Powermatic for a spindle from an 11" Powermatic.

It appears that this is the only difference between the two machines. Remember that this ONLY applies to the Powermatic 10" lathe that is actually an 11" swing. I would also do some serious checking of dimensions before plunking down very much money.

OTOH, you might find a good deal on a spindle on eBay.

Also, I *THINK* you could use a spindle off any Logan 11" Lathe. According to the diagrams and cross-references, the Logan 11" used the same spindle as the Powermatic 11". According to the P/M parts list, the only difference between the 10" and 11" *POWERMATIC* headstock is the spindle itself. The headstock casting, pulley, bull gear, bearings etc., etc., etc. are all the same. This would indicate to me that the outside profile of the two spindles is identical.

Of course, it does mean you would not be able to use the same spindle mounted accessories as you do now, such as your chucks or faceplates.

Good luck!

How about an easier alternative. I recently bought an adjust true

chuck

The cheapest thing you can do that is sort of collet-like is to find a mint Jacobs 58B headstock chuck that threads onto your 1½-8 spindle nose.

Another alternative I don't often see mentioned is to go with a non-lathe collet setup. The last few years I've been using an ER-40 collet set in my shop with various holders and homemade drawbars, on several machines. On my 9" South Bend, for example, I use an ER-40 holder with a 3MT shank. That gives me collet accuracy but without the pass-through capability of real lathe collets. I have used it to turn 1" drill rod. An ER-40 setup isn't cheap new, but there are the usual workarounds (ebay, import clones). I also use these collets on my tool & cutter grinder and can use them on the mill and my bigger lathe too, but haven't yet.

Grant Erwin Kirkland, Washington

David-

I have quite a few used Logan spindles in decent condition, including several with the larger spindle bore.

-Bill Fill snipped-for-privacy@msn.com Olympia, WA

The Bison collet chucks are very rigid so unless you want to take monster cuts the overhang isn't a factor. I like the Bison chucks but I would avoid their collets (the collets themselves, not the collet chucks).

Going with the 5C collet size gives you access to other low cost tooling, such as 5C collet blocks and indexers. I use these all the time on my mill, way more than I thought I would before I added collets to my lathe setup.

I'd go with a Bison collet chuck or make my own collet nose that extends far enough from the lathe spindle for the 5C's to fit. I'd use 3-1/2" or 4" cold rolled bar stock for the nose to make it nice and stiff. Then make a custom drawbar with 5C female threads on one end that necks down to a smaller size tubing that fits through the spindle. On the far end, use a quick release pin to allow the handle to come on and off quickly. The drawbar is then inserted through the front of the spindle and the handle is then pinned on the back end. Since you'll cut the 5C taper with the nose mounted right on the spindle it will have very low runout, likely better than the Bison chuck.

Good luck-

Paul T.

• Posted and Emailed *

Thanks, Scott, for the great tips!

That is interesting. I am guessing it was driven by marketing/price point/commonality of parts, but it sure does seem like a dumb design when I look at the thing. And I feel kinda cheated out of a proper spindle when I know it couldn't have cost them $5 to make it right.

This sounds like a great idea. And RCM comes (hopefully) to the rescue via Bill Fill's post. I sent him the dims and pics of my spindle so he can check it against what he has. I'm emailing them to you, too, if you would know by looking what the compatibility is. I won't try an ascii dimensioned drwg.

One thing I'm confused about is that my "Logan Operators Instructions & Parts List" for the Powermatic 10 and 11, p. 20 (Headstock exploded view), shows 4 spindles. Mine looks like the one in the upper right corner: 2 keyways, long center section. The 3 spindles at the bottom of the page have 3 keyways and a different profile.

Hopefully this spindle swap will work out and I'll have a real "11 inch" lathe (short of the serial number).

Thanks again, David

Thanks, everyone, for your excellent advice. Even more alternatives, and the spindle swap looks like the best one for my case. Thanks again, David