Replacing a spindle on the Kern Micro
We are replacing the spindle on the Kern Micro CNC machine. After three years of ownership, basically I’ve crashed it one too many times and it’s been mostly fine but that combined with running high RPM up to 42 000 RPM more than I need to has reduced the life of the upper spindle bearing causing it to overheat now at 40 000 RPM.
The Kern Micro has temperature sensors everywhere and it thermally controls everything and it tries to keep the chilling system – it’s actually got a huge chilling system – with a air conditioner basically that chills the fluid and keeps it at 20 degrees Celsius. If that upper bearing gets to 50 degrees Celsius it hard cuts the machine and e-stops it. We started having that so I was able to continue running it for the past few weeks by limiting the Max RPM to 18 000 RPM that gets the temperature like 38-39 – 40 degrees instead of hitting that cap of 50. Team Tina from Kern USA is arriving later today and she is going to pull out the spindle and install the new rebuilt one which costs many many tens of thousands of dollars plus the work. She is going to do a full machine maintenance and get everything tuned up and back to normal because we’ve been running it hard for three years and it’s time.
View video here:
Spindle replacement | Kern Micro