New 6" chuck with reversible jaws (finally)

[Mutt]

Hey y'all, I bought a new Griz 4003 in 1999. As with all Chinese lathes, tolerences were out of the ball park, but to be expected. But I was sorta ticked, that the runout on the jaws was horrific (like .010 or more) & first time I had to change out the jaws, I surely wished the chuck would have had reversible jaws. So fast forward 18 years. I bought a new chuck off eBay, $150 including shipping. I didn't have much high hopes except for the fact that it did have reversible jaws !!!

So I removed my old chuck and backing plate, and went to installed the new D1-4 adapter,
so I could machine the shoulder for the new chuck body. Took way more time than I expected
only because it didn't pay much attention to the "lines" grooved into the pins.
I screwed them all the way in, then had to figure out why the cams wouldn't work > I looked at the
original chuck and of course those lines were witness lines.
Live and learn !!!!!
Ok, so I got it all installed and was checking everything out. I tightened the jaws all the way tight,
to see how small of a part it would hold when I noticed the jaws of the chuck
didn't close all the way ???!!! They only touch at the VERY TIP. But when I installed a piece
of rod, so I could see what kinda runout I ended up with, the jaws close tight against the rod,
all the way down? Am I in the Twilight Zone or ????

Here are the jaws , closed tight. About 1/8" gap on one, 3/32" on the next and
the last one is sorta tapered from nothing to 3/32" What gives?

 

[Ebel440]

First thing I would do is take the jaws off and make sure they don't have any chips/burrs messing with the jaws. See how it closes with the jaws off.

 

[Wreck™Wreck]

The feature that you will like the most is the ability to use soft jaws.

 

[Mutt]

wreck, do ya think these jaws might be s0ome sort of "industry standard" Can I buy sets of jaws?

Ebel, I will check the closing with no jaws

 

[Wreck™Wreck]

Yes, American pattern tounge and groove, measure the hard top jaws and compare with these dimensions. There are many manufacturers. They can be welded so that parts far larger then the chuck may be held.
http://www.abbottworkholding.com/chuck-jaws-jaw-nuts/american-standard-tongue-groove-jaws

Pie jaws have nearly 360 Degree holding which is excellent for large thin parts.

 

[Mutt]

I'll sure check that out, good link

 

[Wreck™Wreck]

We use some jaws from here as well, they have online pricing.
http://monsterjaws.com/

 

[Mutt]

Wreck, I'll have a look at that site as well

I checked the master jaws without the reversible jaws installed. Same thing, but on a smaller scale., Still atleast 1/16" at the ends closest to the headstock

 

[DAT510]

Is it a scroll type chuck? If it is, is it possible the Master Jaw locations may have been switched?

Chris

 

[Mutt]

yeah, but I am more inclined to think that Kung Fu really didn't care about the inner angles on the jaws when he ground them. If I can find my protractor, I'll measure all side side angles, I'm pretty sure none of them will be the same as the other. I looked at both websites, couldn't find any 6" American Standard hard jaws. The second place had some for the 8" chucks, for $30 or so a set. I'd be happy to pay that for a set of jaws that were machined right (in the US as well)