Talk To Me About 3 Jaw Set Tru Chucks

Combination chuck is a scroll with independent jaws on the scroll carriers. The smallest combination chuck from Bison is 8" and even if there was a 6", it would be way too heavy for this size lathe. I think the Set-Tru D1-4 6" chuck from PM/QMT offters the best value and performance, their Taiwanese chucks are well made. Anything else other than a Chinese mainland copy will be probably be twice the cost with a back plate. Please not that Set-Tru chucks are not for routine centering of work, they are designed to be set and left, they will repeat typically within TIR of 0.0004" or less for the same diameter stock. Is the spindle a D1-4 or do you have an adapter plate to a bolt on, if the latter the stick out for a small lathe will be a problem.
 
mksj said:
Combination chuck is a scroll with independent jaws on the scroll carriers. The smallest combination chuck from Bison is 8" and even if there was a 6", it would be way too heavy for this size lathe. I think the Set-Tru D1-4 6" chuck from PM/QMT offters the best value and performance, their Taiwanese chucks are well made. Anything else other than a Chinese mainland copy will be probably be twice the cost with a back plate. Please not that Set-Tru chucks are not for routine centering of work, they are designed to be set and left, they will repeat typically within TIR of 0.0004" or less for the same diameter stock. Is the spindle a D1-4 or do you have an adapter plate to a bolt on, if the latter the stick out for a small lathe will be a problem.
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D1-4, has a 1.3 bore on the spindle too. and i was thinking after looking at many, that the PM 6" is prob going to be the one. 99 percent of the time i used the 4 jaw, it will have a ER 40 collet block in it sitting in a offset position,
 
Mark, did Bison discontinue their 6" combo chuck? I bought one earlier this year but it might have been old stock. Dave

EDIT. I just looked and Global is still selling them.
 
The 6" combination chuck might be listed, but no longer available. They did add the 3J versions several years ago, but their current catalog only lists 8" and larger. It would be too heavy for this size lathe in my opinion. The PM chuck I feel is your best bet, they use to carry Chandox chucks which were excellent (David Best has one) but like so many things these days they just couldn't get them anymore. I would check to see what the back order time is on the PM/QMT chuck, otherwise keep a lookout on eBay, sometimes something might come up. Also note that the Set-Tru type back plates for these types of chucks tend to be proprietary (and not interchangeable), they can be quite expensive. It was mentioned to me in the past that Bison, TMX and Gator may be interchangeable as the latter two are spin offs from people that left Bison and copied their chuck designs.
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A 1.3" spindle bore is pretty small for a D1-4 spindle - usually they are 1.5" dia or a bit larger. I have an 11" lathe with a D1-3 mount and it has a 1.38" spindle bore (double check the size).

Setting up the 4J is slow? Hang in there - it gets quicker with practice - to the point that you hardly even think about it. A 6J scroll is a nice to have - but it does not replace any of the other work holding equipment. In my experience, the 6J compared to the 3J - is heavier, sticks out further, has longer jaws so they are usually protruding past the body (catchy), and doesn't grip as small (especially when holding outward inside a bore).

Of course a 6J set true is nice, but is very much a luxury in general machine work.
 
Chipper5783 said:
A 1.3" spindle bore is pretty small for a D1-4 spindle - usually they are 1.5" dia or a bit larger. I have an 11" lathe with a D1-3 mount and it has a 1.38" spindle bore (double check the size).

Setting up the 4J is slow? Hang in there - it gets quicker with practice - to the point that you hardly even think about it. A 6J scroll is a nice to have - but it does not replace any of the other work holding equipment. In my experience, the 6J compared to the 3J - is heavier, sticks out further, has longer jaws so they are usually protruding past the body (catchy), and doesn't grip as small (especially when holding outward inside a bore).

Of course a 6J set true is nice, but is very much a luxury in general machine work.
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the stuff i will be making, i won't have time to monkey around with a 4j constantly
 
Chipper5783 said:
A 1.3" spindle bore is pretty small for a D1-4 spindle - usually they are 1.5" dia or a bit larger. I have an 11" lathe with a D1-3 mount and it has a 1.38" spindle bore (double check the size).

Setting up the 4J is slow? Hang in there - it gets quicker with practice - to the point that you hardly even think about it. A 6J scroll is a nice to have - but it does not replace any of the other work holding equipment. In my experience, the 6J compared to the 3J - is heavier, sticks out further, has longer jaws so they are usually protruding past the body (catchy), and doesn't grip as small (especially when holding outward inside a bore).

Of course a 6J set true is nice, but is very much a luxury in general machine work.
Click to expand...
i was questioned about whether it was a D1-3 or a D1-4 when i first started discussing this lathe, i thought at first it was a D1-3 because of the "three studs", but was told to measure the studs, when i measured the pins, it measured for a D1-4, the studs on this chuck are .625 which is the size for D1-4..
 
Save up and buy a good chuck like the Bison. Nothing more frustrating than a chuck that won’t repeat. I’d expect 2-3 thou out of a new 3 jaw. If you need closer than that adjust the set true. Watch the top speed and make sure it’s enough for your lathe. I’d also recommend you get one with removable top jaws. Then you can do pie jaws, special jaws soft jaws whatever. Very handy. It’s a major investment. If you are brave and have a tool post grinder and patience you can get old USA made chucks and refurb them. Just make sure the scroll is good and the taper on the mount is not worn or scarred and …. Well maybe just buy a new Bison
 
ok,, just found out, that the PM chuck will not be stateside again till about May or June of next year.. the search will continue, but at the moment, might consider a Gator
 
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