Ideas on Parts or a replacement for a 24" Universal L3 4-Jaw Chuck.

I'm looking to fix or replace a 24" 4-Jaw Chuck on our 1948 American Pacemaker 25 x 72 with a Serial # 71102-48. I am told it was originally equipped with a "Universal" Chuck (Tagged 2140110) but I'm coming up dry trying to replace a broken adjusting screw and guide for one of the Jaws. Adjusting screw is 9-1/4” long and the jaw guide is 2-3/4” long. The jaw guide has 960 or 096 stamped on the bottom. It reads either way. No idea where to get parts and Bourn-Koch is a non-starter. I have also been told it is a L3 connection off the output from the machine by someone on Ebay I was trying to buy a replacement 21" Chuck from that turned out to have a L2 connection. The L3 connection has a 10-3/8" Top Thread and a 10" Bottom V Thread at 4 TPI and an inch of threading. I am open to ideas from the Pro's in this forum as I am not a Machinist by trade. I need to get this machine back in operation at our Valve shop by hook or by crook. If I can find the parts that would be great because I hate to junk this old Chuck. If not, I would be interested in any leads where I could get another 21" to 24" 4-Jaw L3 Chuck so we can start turning again.

Gator sells a 359 Lb 25" plain back if you want to turn your old chuck into an adaptor plate - see thumbnail

18" if not too small - be sure and check if actually L3

PRATT BURNERD 18” 4 Jaw L3 Spindle Mount Manual Lathe Independent Chuck | eBay

Yeah, 18" is going to be too small. We were willing to go down to 21" and I've been hawking Ebay hoping something shows up. I'm not in the business per se so I don't know which Vendors move old equipment. Hoping to find some oldie but goody 21" - 24" L3 Chuck and just swap the whole thing out. I can't go bigger than 24" either. Between a rock and a hard place.

Some of the folks who were at one time the US-makers of decent chucks have survived on resale of imports for the admittedly diminished market for small 'manual' chucks (CNC are usually power-operated), by.. ta da.. offering full rebuild services of the costly larger manual chucks. Serious rebuilds, not just the odd replacement part.

Have a look around.

Not all are worth a full rebuild - cheap it is not - but many are - given that NEW ones cost the very Earth anyway and not all of them are as good to begin with as some of the old ones were.

"Plan B".. the least-cost way in dollars to get back up might be to source an entire lathe in good condition WITH a good chuck. Transport is a factor, but as said, chuck rebuild services are not cheap.

"Plan C" the parts you need are not hard to make or HAVE made.. IF the chuck body & c. is not pranged, cracked, or ragged-out.

4-J's will take a downright horrible level of wear and abuse, still get a job done, even if that means working with a stash of copper cut out of 100 HP Dee Cee motor commutators to shim bell-mouthed jaws. DAMHIKT.

try small tools in ohio, Small Tools Inc. - Industrial Machinery, Tooling, Parts, & Accessories (don't be fooled by the name!) bought a few things from them, good experience so far. give them a call, helpful and knowledgeable. good luck, cheers!

I'd like to have the Pin and Connector made but I have no idea who to call. Just not really in that world.

Yep, I saw some of their stuff on Ebay. I'll give them a call tomorrow. Thanks

I think these guys can fix you up...http://o.hrmfg.com/

JS said:

I think these guys can fix you up...http://o.hrmfg.com/

Click to expand...

Thanks! This is looking good and he sent us a spec sheet to fill out on the adjusting screw and guide. Looking promising so far. Fingers crossed. Good lead.

Iceman,

If you are interested, I have a 21" 4-jaw that could be adapted with a back plate. It currently has a D1-8 back. It is a steel body chuck and appears to been used very little. Send me a PM if interested. BTW- Where in Texas are you located?

Ken

Thanks for the offer Ken but JS gave me a tip and got me hooked up. H&R Manufacturing is making us both parts at what we consider a reasonable price and cut us a price break on a set of 4 instead of 1. They sent us a sheet to fill in the dimensions and that was all there was too it. It will take a few weeks to make them but we are good with that. We are going to pull the other Operating Screws and Thrust Bearings and hold them as backup for this machine and another one we have at our other shop. All's well that ends well and a tip of the hat to JS. I knew I would get an answer here!

Spec Sheet: