cmjohnson
Hot Rolled
- Joined
- Jan 22, 2009
- Location
- Central Florida
For reasons I admit I just don't know, I'm having a problem with my knee mill's X axis trying to unscrew itself every time I either use the power feed or even turn the handle manually. This happens whenever I am turning the X axis screw clockwise as seen from the right side of the mill.
Of course what's happening is that the screw assembly is just unscrewing itself from the threaded retaining nut.
Look at this photo and you'll see the black nut I'm talking about. Not sure what it's called.
I know that it's not supposed to do that but every time I advance the X axis in the leftward direction, the whole lead screw assembly attempts to screw itself right out of that nut.
So what's going on here? What part(s) am I missing and/or have installed incorrectly that would cause this?
I have on many occasions considered a brute force approach, drilling and tapping the locking ring for a set screw and using that to clamp down hard on the brass threads underneath, but that's so crude.
I'm also having a little bit of an issue (possibly related) with determining the proper spacer thickness required to set up the lead screw properly between the left and right handle assemblies.
The lead screw in this mill is not factory original. In fact this mill has ball screws. It's a Sharp YC 1 1/2VA which I retrofitted with a QC30 spindle. (Possibly making it the only QC30 equipped mill of this model in the world, for all I know.) It just took two parts and one modification to make a Bridgeport Boss QC30 spindle fit and run in this mill. That was easy. Getting the X axis to try to NOT unscrew itself when I use it, now that's been a challenge!
I'd THINK that the correct way to set this up would be to add spacers as needed so that the shoulders of the lead screw matches to the shoulder spacing between the bearings in both end plates. But with the power feed, that's a little less clear.
Of course what's happening is that the screw assembly is just unscrewing itself from the threaded retaining nut.
Look at this photo and you'll see the black nut I'm talking about. Not sure what it's called.
I know that it's not supposed to do that but every time I advance the X axis in the leftward direction, the whole lead screw assembly attempts to screw itself right out of that nut.
So what's going on here? What part(s) am I missing and/or have installed incorrectly that would cause this?
I have on many occasions considered a brute force approach, drilling and tapping the locking ring for a set screw and using that to clamp down hard on the brass threads underneath, but that's so crude.
I'm also having a little bit of an issue (possibly related) with determining the proper spacer thickness required to set up the lead screw properly between the left and right handle assemblies.
The lead screw in this mill is not factory original. In fact this mill has ball screws. It's a Sharp YC 1 1/2VA which I retrofitted with a QC30 spindle. (Possibly making it the only QC30 equipped mill of this model in the world, for all I know.) It just took two parts and one modification to make a Bridgeport Boss QC30 spindle fit and run in this mill. That was easy. Getting the X axis to try to NOT unscrew itself when I use it, now that's been a challenge!
I'd THINK that the correct way to set this up would be to add spacers as needed so that the shoulders of the lead screw matches to the shoulder spacing between the bearings in both end plates. But with the power feed, that's a little less clear.
