PM1228 Chuck

[Bryan40g]

There is a number in addition to the 1, 2, 3 for the jaws that are usually serial numbered to the chuck so you know which chuck it belongs too. I don’t know if they do that for these economy chucks, but higher end chucks have the jaws ground to a specific chuck body and will not give good results if used in another chuck. Here is a picture of the #1 inner and outer jaws with the different serial numbers.

View attachment 355471

I cleaned the chuck as best I could and the runout did not change, so I suspect these jaws belong to a different chuck than was shipped to me.

This is exactly what I was thinking regarding the purchase of additional jaws. I think it best for me to plan on purchasing another chuck. Direct mount or true-tec

 

[Ischgl99]

This is exactly what I was thinking regarding the purchase of additional jaws. I think it best for me to plan on purchasing another chuck. Direct mount or true-tec

I have a Bison 5” 3 jaw chuck with removable top jaws I bought years ago when I had a 9x20 lathe that I like a lot. Having the removable jaws is nice since you can make soft jaws for specific purposes. I haven’t done that yet, but it’s nice to have that option.

 

[pacifica]

Looking for thoughts on the 6” chuck that comes on the machine. As well as the optional 8” 4 jaw chuck.

I’ve got til mid May when my machine arrives and I’ve noticed that the 6” chuck has solid jaws and not two piece. So I’d need another set of jaws. Not sure I like the idea of buying jaws hoping they’ll fit correctly. So I’ve been looking at 6”chucks. Considering a Gator 6” 3 jaw with 2 piece jaws. Have not heard anything but good things about their chucks.

I guess my question is are you happy with the 3 jaw chuck that comes installed? How is the runout?

The first 3 jaw on my 1340 gt had about .001 to .0015 R/O depending on the diameter. It cracked about 1.5 " long on the body in use( a close call).
The replacement I received( after 5 emails and same number of phone calls) Actually had the name of a taiwanese well known chuck mfr with a serial number. It has the same amount of run out.
This is equal to a new 6" 3 jaw bison chuck given to me. Since I made the back on the bison I can get R/O to .0007 by light tapping, but it changes when the diameter of workpiece changes.

 

[SRay53TxTn]

I can check my 3 jaw that came with my PM1228 and 4 jaw chuck in the morning. I purchased the 8" 4 jaw from PM it has reversible jaws and has Taiwanese mft stamp (they always seem to be on BO). Both have performed well.

 

[Bryan40g]

I can check my 3 jaw that came with my PM1228 and 4 jaw chuck in the morning. I purchased the 8" 4 jaw from PM it has reversible jaws and has Taiwanese mft stamp (they always seem to be on BO). Both have performed well.

The first 3 jaw on my 1340 gt had about .001 to .0015 R/O depending on the diameter. It cracked about 1.5 " long on the body in use( a close call).
The replacement I received( after 5 emails and same number of phone calls) Actually had the name of a taiwanese well known chuck mfr with a serial number. It has the same amount of run out.
This is equal to a new 6" 3 jaw bison chuck given to me. Since I made the back on the bison I can get R/O to .0007 by light tapping, but it changes when the diameter of workpiece changes.

Cracked! Not good. Definitely going to replace chuck then. Even if that’s a rare occurrence. I think a semi steel direct mount from gator or bison is the route I’m going to take. I don’t want to take a chance.

 

[Larry$]

My PM lathe came with both a 6" 3 jaw and an 8" 4 jaw. New 3 jaw chucks always come with both inside and outside jaws. There is a little runout on the 3 jaw, doesn't matter since when using a 3 jaw you can't reverse the work anyway w/o loosing concentricity. Well not quite true but you would have to have a Run-true back and then mess around with getting it centered again. Might as well go directly to the 4 jaw. It seems like a scroll chuck would always have more variations, less repeatability than other more adjustable or less moving parts methods would. I've got a 3 jaw 8" with 2 piece jaws. It was a more expensive Taiwan chuck but has more runout than the PM 6". I can change out jaws about as fast as I can reverse the two piece ones, so not much advantage. My favorite chuck is a 5C collet with run-tru back. I got it with the lathe as an optional extra. Very nice chuck. My go to for work up to 1 1/8". Work can be taken out & put back in or reversed with very accurate repeats. The disadvantage to 5C is the work has to be a relatively close fit to the collet.
As for tapping the chuck to center, if it is a cam-lock mounting, I've never tried it. Seems like there would need to be some slop in the fit between the spindle mount and the chuck for that to work. They fit into a taper so there should be no slop??? (Assumes correctly done tapers) All my chucks fit snuggly enough that they require a few taps with a soft face to get them to release.
If you are really new to cam-locks make sure you have adjusted the studs correctly.