Knee mill X- axis power feed repair ?

[cuslog]

Any one here with experience taking one of these apart ?
Its on a "Modern Tool" bridgeport clone - about 10 years old.
Everything works (mostly) except the variable speed control is kind of "funky" at the slower settings as it gets warm. Cold, the slower settings work but after a few cycles they get troublesome. I can make them work if I turn up the speed setting to almost top speed to get it going, then back it down - far from ideal. I have also got them working again by removing the speed control knob and spraying contact cleaner on the shaft but this only lasts a few days and its back to where it was. This leads me to believe the problem is in the speed control pot and I'm thinking that maybe if I can get directly to the pot a good spray with contact cleaner directly on it might solve the issue.
So, I've watched a couple youtube vids - looks like everything drops out the bottom as a "unit". I've got it off the machine, removed 4 SHCScrews that appear to hold the bottom to the top, it seems loose but also feels like there may be something else holding it together. Before I use too much force and break something I thought I'd ask here if any one has any experience taking one of these apart ?
TIA
Howard

 

[combustable herbage]

Sure sounds like the pot is dirty depending on the type of pot you may or may not be able to get a good cleaning, if not you should be able to source a replacement once you see what it looks like.

 

[Brian Ross]

I had the same issue a couple of years ago. If it is like the one I have, you can disassemble the unit without removing it from the mill. But, if I remember correctly, you have to pretty well remove everything to get at the potentiometer. I ended up replacing the pot and the unit has worked fine since. In hindsight, contact cleaner probably would have worked ok as well.