4 Jaw Chuck input for PM1228, PM's High Precision 8" vs.

[mksj]

As I mentioned, although I do not use my 4J independent often, but for some jobs it is handy to have. Today I had to bore an off-center hole and then do a M30 x 1.5 thread, the boring I coul have done with my mill but not the threading. The PM/QMT chuck was spinning at around 450 RPM for boring and 250 RPM for threading, handled the task w/o and issues. My lathe is around 2500 lbs, so even with the chuck jaws way out of balance there was no vibration. One also needs to take into account the clearances with the jaws extended as well as having enough jaw teeth engaged (i.e. do not over extend the jaws). The PM/QMT 4J independent chuck offers good value and works just fine.

 

[Christianstark]

I have the PM 8” 4 jaw and it is a good quality chuck. It is balanced at the factory, so that could partially explain the higher speed ratings over the Gator. I have no issues running mine up to 1,800 rpm on a 12x36 lathe. The jaws were a bit stiff when I first got it, making dialing in a challenge at times, but after using it a bit, it is smoother. I think it is a very good value for the price.

Mine was stiff as well, but I did some light filing and is good to go now.