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Maximum RPM for Jacob's Chuck

nhtr86

Plastic
Joined
Dec 12, 2015
I am using a (new, not old school) 14N Jacob's Super Chuck on a bridgeport. I feel comfortable with it at the 2000ish rpm that I've been using it, but I'm getting some push back from the nervous nelly looky loos. I figured I would go straight to the Jacob's literature and find the max rpm and settle the issue, but wasn't able to find anything about rpms and that seems ridiculous. I'm assuming that it would be fine to the 3000ish max rpms that the machine can put out, but now I'm wondering why they don't specify a max. Am I correct that whatever minor out of balance the chuck has will cause problems before it is a safety concern? Anybody have a source for a definitive max rpm for a Jacob's brand super chuck?
Thanks
 
I can't imagine the chuck itself is much of an issue, but what you put in it is a huge factor. Something with a large length to diameter ratio could limit you to a very low speed. There was a thread on a similar topic recently, but I think it was lathe stick-out.
 
Is it integrated into a R-8 collet or on a straight shank. I would think either would be fine to 3000rpm considering the powermatics we have go up to 2400rpm and they are setup with chucks on m3 adapters. All things considered you gotta spin those tiny drills fast if you want to do any real drilling in aluminum
 
almost any cheap china made drill press with a china chuck goes up to 3000rpms.. some very high quality chucks meant for cnc machines can go as high as 12000rpm.

We ran are old school 5/8 Jacobs in are cnc at 4000 to 5000 rpms years ago and had no problems. If we ran out of tool holders or correct size collets we just put the drills in Jacob chucks to free up tool holders for ends mills.
 
The rpm and the chuck are somehow matching by the fact that for small drill and high rpm one would use a smaller chuck. Not only a small chuck can run fast, it will, in most cases, be more accurate in the drill size range it is designed for - and small drills need high rotational accuracy. For small drills, about 1mm diameter, I am using an Albrecht "Super Drill Chuck" 0-1.5mm and this is rated 50,000 rpm. Smaller drills (under 1mm, and here using mostly carbide drills with 1/8 shank) I am holding in a very accurate 1/8 collet.
 








 
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