8L spindle bearing adjustment?

Harrison_Reed · March 14, 2026, 12:15pm

My 8L spindle has visible play in the Z-Axis. I got the machine in June 2025, and I was so new to machining that I didn’t realize that this was probably not supposed to happen. I guess I assumed that tensioning the draw tube would hold everything in place.

Basically the spindle is a little noisy unless the RPMs are high, and when removing parts from a collet or the 4-jaw chuck from the spindle, you can see the tapered end of the spindle visibly move out in Z positive.

I can make parts in brass and they are accurate to my specs (I think that is because all the tool force during cutting is in Z negative), but I feel like I need to address this problem soon. I can’t find any guidance in the manual for how to eliminate this play. Looks like maybe I need a special spanner wrench to tighten the rear bearing retention plate? I might be completely wrong with what needs to happen.

I really don’t want to dissemble the spindle and realize I don’t have what I need to get this thing fixed.

Anyone done this? It’s pretty much brand new still, so I doubt the bearings failed.

Harrison_Reed · March 20, 2026, 10:24pm

Well, I’ll reply to my own topic – I set up a support request and got an answer that supported my thought that you can adjust the play of the spindle by tightening the rear bearing retention nut.

A special spanner is needed, ideally, but it can also be adjusted with gentle taps using a flat nosed punch on the two notches in the nut. There are a bunch of retention screws going through the perimeter of the nut that need to be loosened first. I’m going to take a look at doing this tomorrow and will see how it goes.

Harrison_Reed · March 21, 2026, 2:44pm

This is the way you adjust it. Completely fixed my issue!

You can see by comparing the attached photos to the video (which was before I was done, I made more adjustments) just how “out” the spindle was. The business end is now flush with the front retention plate. The spindle now is much more exposed through the rear bearing nut.