[nlh]

I have an early 80's (~83-84) LB15 w/ dovetail ways on the X axis. I have had backlash for quite a while and dialed it out as best as possible w/ backlash comp in the control. I did that a couple years ago but it's been slowly getting worse.

I would like to gain access to the thrust bearings and ball screw to inspect them both (and most likely replace at least the thrust bearing while I'm there).

The thing is, I'm not sure how to get to them.

Looking at my parts break down, there is a small metal plate that covers the lower bearing block where the thrust bearings are housed (only show's thrust bearings on lower end of the screw, w/ a 6205 ball bearing to support the servo end). Looking the machine over, this cover is pretty much completely covered by the turret. The turret is at it's upper limit and won't go up any higher, at least while under servo power. Is it possible to move the ball screw by hand and bring the turret high enough to take off the cover?

Really haven't dug into it too much at this point before I got more information. Was hoping someone on here might have firsthand experience with the same machine/repair that they could share.

Thanks

[DouglasR]

I have the identical machine.
I believe you have to remove the D6 encoder first.

[underthetire]

Hope you have a surface grinder..
Okumas use a ground shim to set bearing pre-load on most of the machines. This is ok if you can get an exact matched set, but being that old and newer bearings not usually coming in matched sets (universal grinds) you may need to make a new spacer. As far as that cover, the X wiper has to come off, and the axis at the upper limit. If the limits have been changed, you can move them up in the control, just keep an eye on the overtravel switch. If you hit the switch, the release is inside the electrical cabinet. I vaguely remember two bolts under the front of the X axis that come up from the bottom, but it's been 20 years now since i touched one.