Chuck Question

[Henryrifle]

I am looking at this Precision Matthews adjustable chuck. Thinking that I could use it as a chuck upgrade from my stock Grizzly 4-jaw and have it act like a 4-jaw chuck by adjusting the entire chuck rather than a jaw at a time.

I am guessing that is not the intended use--rather the chuck should be adjusted to true once and left alone until it needs adjustment again. Is that right?

I really like the idea of the true bore alignment system (TBAS) but I know I don't have the right lathe for that.

Thank you,
Hank

 

[762plinker]

no..not excatly
you dial in a part and when it is true, you can then remove and add a SIMILAR part and it to will be true to the chucks specs

 

[LVLAaron]

I am looking at this Precision Matthews adjustable chuck. Thinking that I could use it as a chuck upgrade from my stock Grizzly 4-jaw and have it act like a 4-jaw chuck by adjusting the entire chuck rather than a jaw at a time.

I am guessing that is not the intended use--rather the chuck should be adjusted to true once and left alone until it needs adjustment again. Is that right?

I really like the idea of the true bore alignment system (TBAS) but I know I don't have the right lathe for that.

Thank you,
Hank

The "PM" chucks are made by Auto-Strong. They're incredibly nice and well made. My non-adjustable 3 jaw is within 2 thou and dead straight. (After buying a ground bison backplate)

Yes, it can be moved like a 4 jaw with the "set true" style screws. If it's the only chuck you had, could you make it work for barrels? Absolutely. However... it's much easier to use a 4 jaw for barrel work.... and you can get a Gator 4 jaw for a lot less.

 

[jackieschmidt]

The object of a “set true” chuck is for indicating a specific section of a part that does not nessessarilly run true with the section that is held in the chuck jaws.

A barrel is good example. The OD, which is round, does not run true with the ID. You are chucking on the OD. You can use the four “set true” screws to get the ID running exactly where you want it.

What that is is the subject for an entire different thread.

Since the chuck jaws are now running out with the centerline if the lathes spindle, anything else you Chuck up will not be running true.

you can put a piece of precision round stock in the jaws and then using the set true feature, indicate it dead true. Then you can be reasonably sure that other pieces will run reasonably true.