Just removed the Z axis Ball Screw on our Quick Turn 8. I was quoted 8 to 10 K for the job with a new replacement Ball Screw. We did it ourselves and the rebuild for the screw will run about $600.00 with new Bearings. The problem was the bearing at the motor drive end. If anyone needs a Tip the whole unit comes out with the Motor attached.

If the requirement for Ball Screw Repair or Rebuild surfaces again, you may like to keep us in mind. We repair ball screws and build new ball screws -

Precision Spindle & Accessories Inc.

www.precisionspindleinc.com tel. 519 671 3911
haviland@precisionspindleinc.com fax. 519 652 5994

i would allways shoot for thrust bearings before pulling a screw

All three posts are very good things to know. Thanks!

-90% Jimmy

I found it easier to just remove the whole unit. By the time you remove all the screws from the coupler it was out. To prevent a repeat I ordered all new wipers for the panels to prevent all the trash and coolant from entering the lower drive area. Thanks for the name, I have it on file for any other ball screw problems.

i was referring to how i would spend my money not how i would take it apart.
mazak ball screws are top shelf, in my experience lost motion is generally in the thrust bearings, i have had 1 screw go bad on a QT8 but have replaced many thrust bearings.
now, if i had the motor uncoupled and the screw felt like a bag of rocks thats when i would look at replace or repair of the ball screw.
I'm not arguing or disapproving of your work, you got your machine up and running and saved a bunch of money over giving someone a blank check to do the work, I'm just stating what i have run across in 25+ years of doing this for the next guy that does a search on ball screw, leaving that screw in and just replacing the bearing on the ends of the screw could save alot of time and money.

Good thread, this is a keeper

You are correct. The screw was Fine and the bearings were bad. Because the machine is 20 years old I felt the best procedure is to remove the whole unit and have it overhauled. This consisted of replacing both end bearings and all the balls inside the screw cage. The unit was then shimmed for the correct clearances. I will say on this machine it is a lot easier to remove the entire screw even if you are just replacing the thrust bearings. Thanks

Could you provide more detail as to how you removed the Z-axis ballscrew?

The ballnut is attached inside of an adapter part with 4 bolts. This adapter fits precisely up into a slot in the carriage or turret (depending on axis).

My thinking is you must remove the 4 bolts holding the ballnut to the adapter, and basically leave the adapter in place. Otherwise to remove the adapter, it would have to be unbolted from inside the carraige/turret, and then dropped straight down at least 1/2" to come free. No way is a man going to drop the adapter down with the ballnut and ballscrew still in place.

Am I making any sense here???

Greg