4 Jaw for my 9" South Bend

I just picked up a used 9" SB. It only came with a 3-jaw chuck, but I'd like to find a 4-jaw for those jobs where I need to remove the part, and re-center it.

What should I be looking for as a ballpark price range? Should I expect to pay upwards of $100 or more for a used one?

Any suggestions for someone on a budget? They don't seem to come up on craigslist all that often.

I was on a tight budget, and got an import 4 jaw from Jeff at tools4cheap.net. It is reasonably well built, hardened screws and jaws, jaws are square to the body, etc. However, the movement of the jaws was tight and uneven, with one jaw in particular binding once per screw rotation (I think the screw bearing area is eccentric to the axis). It also had a number of sharp edges, and a bit of uneven grinding on the jaws. Some of this stuff can be fixed by some time with a stone. Its ok for what I paid, but next time I'll spring for something a bit nicer.

allan

If you're looking on CL, you may have quite a wait. For used I'd look at either ebay or Plaza Machinery. in Bethel VT. Unless you know and trust the seller, ebay is dicey. Joe, at Plaza, has quite a selection, and I would tend to trust him much more than a random seller off of ebay.

If you're wanting new, I've heard good things about Gator Fuerda chucks, which are Chinese, but high end, as far as China. You can buy them through tools4cheap, expect to pay in the low $200 range. The next step up is a Bison, now you're looking at $450 or so. If you go that way, and you can wait, you might want to purchase through Enco and wait for one of their 20% off promo codes to come around.

Paul

I've sold a few good used Skinner 4 Jaws on eBay... they've typically gone for around $100.

I would use Plaza Machinery (as listed above) or Craig Donges from Ohio (Google it)

I'd be really cautious about buying a used chuck unless you have a clear understanding that it can be returned for a refund if it doesn't work correctly. We bought a used Skinner and it never was straight and could not be made straight because of wear of the jaws and the jaw guides. As a result, the axis of the workpiece could not be made to coincide with the axis of the spindle. Purchase a good quality import or save up and get a Bison. The Bison price will make your eyes water but you'll never be sorry you bought it. I have a Bison 6" 4-jaw and it's a pleasure to work with.

Some think the 4jaw is the cats meow for high precision but truth is that many are good at the point of indicating and truing in only. Outboard an inch or a few, or inside the chuck there may be wobble.

Poorest quality chucks may be bad from the very start because of sloppy manufacturing or may fail quickly due to wrong metal or hardness errors. A top quality chuck (and the better one) will have wear areas heat treated somewhat to be from tough to hard.

To get a part running true for some length of part one needs a good quality and good condition 4 jaw. (I have used 3jaws that were very close and some that the whole chuck location could be adjusted)

Then care is required: Over tightening a poor quality chuck may damage it and under-tightening might let a part slip. It is not uncommon to over crank to get the last tenths and that can harm a chuck.

If I bought used I would ask seller to test it 3 inches out. Not much worse than buying junk you can't use.

Also good choice is to finish between centers or use a steady for closest finishing.

A good thread for PM “New chuck testing at chuck and out 4inches”


Re-truing a mini chuck you tube video
I don’t completely agree with his clamps but they did work.
Retifying the chuck of Sherline lathe "HD" - YouTube

Buck

michiganbuck said:

If I bought used I would ask seller to test it 3 inches out.

Click to expand...

Buck,

So just for clarification, you would test a 6" chuck by extending the work out 3" beyond the diameter?

Most all chucks are only spec'd to support the work at the diameter, so unless I'm misunderstanding you, I fail to see what useful data that would provide.

Maybe I'm missing something...

Can you explain this better?

Cheers,
Alan

Alan,

I am sorry if I did make that clear. I could have said 3" away not out.

You can indicator zero a test bar (perhaps 1”dia x 12” long) close to the 4jaw chuck (or for a 3jaw just mark it for high and low.) With turning by hand only.

Then with the same chucking indicate at perhaps 3 to 10” (or more) inches away from the chuck and mark it high and low.

This test will tell (approximately) how much run-out the work is running straight, but off center all the same way) and How much wobble off axis as if it were mounted on two centers that were not the same or true to center.

With wobble you can zero close to the chuck and still have a lot of run out away from the chuck.

Buck

"you would test a 6" chuck by extending the work out 3" beyond the diameter?"

Basically yes.

A chuck has to do a bunch of 'stuff.'

It has to securely grip the workpiece to resist cutting forces.
It has to permit the workpiece to center to the degree required.
It has to have the axis of the workpiece (no matter what the size) be parallel to the spindle axis.
It has to resist wear and be easilly adjustable.

If the jaws are sloppy in the body of the jaw, it won't be able to do the first or third.

For the original poster: a brand new four jaw chuck is not that expensive. The advice to STAY
AWAY from used chucks that you cannot inspect closely, in person, is gold.

It might look just great, and be so much scrap iron.