Mori Seiki CL Lathe Series Spindle Repair

Mori Seiki CL-150 “Rumble”

High Speed Technologies, repairing spindles for over 30 years. The Mori Seiki CL-150 is just one of the many Mori Seiki spindles we have seen come through our doors. For your spindle repair questions call HST today 1-603-483-0333.


Mori Seiki CNC Lathe spindles such as this Mori Seiki CL-150 are very robust and reliable. However the spindle is only as good as the motor driving it. This was proved true when one of our customers, a leader in the manufacture of driveline and steering components for the automotive industry, called us with what they believed to be a spindle problem.

After installing their spare CL-150 spindle, they observed a noticeable “rumble” and assembled runout at the shaft face at just 500 RPM. Concerned that they were dealing with a spindle defect, they removed the spindle from the machine, crated it and shipped it to us for a Free Evaluation.


Upon our receipt we immediately set the spindle up on our test stand and checked the assembled runout on the shafts face and taper. The runout was well within acceptable limits on both surfaces. This was the first indication that the spindle was OK. After verifying the runout we slowly ramped the spindle up to 500 RPM. We did not detect the “rumble” that the customer had witnessed at their end. In fact the spindle ran wonderful.  At this point we felt comfortable increasing the speed by 500 RPM increments until we reached the maximum speed of 6,000 RPM. Still the vibration and alignment numbers were exceptional at .01765 IN/S and .61350 G respectively. The spindle was running cool for five hours at 105° F without any coolant.

Our stringent testing ruled the spindle out as the cause of their problem.  So we recommended that our customer turn their attention to the drive motor in the machine next. We soon learned that the drive motor bearings were failing resulting in excessive noise and vibration which translated to vibration and runout at the spindle end.


Our meticulous preliminary testing and honest evaluation saved our customer from having to purchase a new Mori Seiki spindle from the OEM. If you suspect that your Mori Seiki spindle Lathe or Mill spindle is having an issue but you’re not positive, please send it in. Our evaluations are Free and there is No Obligation. Give us a call, we’ll answer the phone 1-603-483-0333!