Ball screw repair and rebuild
A ball screw rebuild restores lead accuracy, preload, and backlash to the original print specification — through raceway and journal grinding, a full ball and return-system replacement, and end machining where the journals have worn. When a screw is beyond rebuild, our ISO-certified facilities can manufacture a new one from prints on file.
Why is your machine losing positioning accuracy?
When parts start coming off size, the axis is usually the last place anyone looks — and the ball screw is usually where the problem is. Backlash is the symptom operators notice: the axis reverses and travels a short distance before the table actually moves. On a CNC that shows up as a witness mark at every direction change, circular interpolation that no longer closes round, and dimensions that drift depending on approach direction.
The underlying causes are mechanical and progressive. Ball wear and raceway spalling open up the clearance between screw and nut. Preload relaxes as the ball path wears. Contamination — coolant, chips, failed way covers — accelerates all of it. Journal and bearing wear at the ends adds its own lost motion that looks identical from the operator's seat but needs a different fix.
A rebuild addresses all of it at once: raceways are reground, balls are replaced and preload reset to spec, journals are machined true, and the assembly is measured for lead accuracy before it ships back.
Reverse engineering and new manufacture
Some screws are past rebuilding, and some are simply no longer available. On older equipment, and on imported machines whose builder has left the market, an OEM replacement can be a dead end regardless of budget.
Our facilities keep prints on file and can manufacture a new ball screw from them. Where no print exists, the existing screw is reverse engineered — lead, diameter, ball circuit, nut geometry, and end configuration measured and documented — and a new unit produced to match. That process also creates the print, so the next time the same machine needs a screw the answer is already on file.
This is often the difference between keeping a productive machine and scrapping it over a single unavailable component.
What a rebuild restores
| Condition | What you see on the machine | Corrected by |
|---|---|---|
| Excess backlash | Witness marks at direction changes, out-of-round interpolation | Ball replacement and preload reset |
| Raceway spalling | Audible rumble along travel, rising drive current | Raceway grinding |
| Journal wear | Axial play at the bearing end, position drift | End machining and bearing replacement |
| Lead error | Dimensional drift over long travels | Regrind, or new manufacture from print |
| Contamination damage | Rough motion, short service life after prior repair | Full rebuild plus wiper and seal replacement |
Ball screw capabilities at a glance
- Complete ball screw rebuilds
- Raceway and journal grinding
- Ball replacement and preload reset
- End machining and reverse engineering
- Backlash reduction
- Acme and ground
- Single and double nut
- Metric and inch
THK · NSK · Bosch Rexroth · Hiwin · Rockford · SKF — and many more
Ball screws and spindles fail for related reasons on the same machine — contamination and thermal cycling do not respect component boundaries. If an axis is showing symptoms, it is worth checking thespindle at the same time.
Downtime doesn't wait for business hours.
Send the make, model, and what it's doing — or call the emergency line and talk it through. We'll tell you whether it's a rebuild, a replacement, or something you can run until the next shutdown.