I have a variable speed Bridgeport mill which I bought new 40 years ago. Two years ago I had the bearings replaced, new belt and everything checked out. Since then it has developed an annoying problem in that the spindle speed will slowly speed up on its own. Most notably in the mid speed range.
Has anyone out there experienced a similar problem? Thanks in advance.
Jeff Smith
Bridgeport Series 2 problems
- Bill Shields
- Posts: 10582
- Joined: Fri Dec 21, 2007 4:57 am
- Location: 39.367, -75.765
- Contact:
Re: Bridgeport Series 2 problems
My experience is that it is a worn bushing, allowing vibration which allows the pulleys to wander.
Assuming that while it is wandering that the speed adjustment handwheel is also rotating
Assuming that while it is wandering that the speed adjustment handwheel is also rotating
Too many things going on to bother listing them.
- Old England
- Posts: 120
- Joined: Thu Oct 05, 2006 1:44 pm
- Location: Bath, UK
Re: Bridgeport Series 2 problems
I recently overhauled my Chinese heavy duty varispeed turret mill; clearly derived from the Bridgeport. I can't immediately think of how this can be happening other than as Bill suggests, there is some problem with the speed adjusting control, must be backing off due to vibration. Perhaps whoever rebuilt it interfered with the adjuster at the back of the speed control shoe? H&W Machine Repair and Rebuilding Advise never to touch this, just lift off the whole top cover and shoe mechanism as one.