Quote Originally Posted by rgsparber View Post
If you are running CNC, the static must not be getting into it or you would crash. I'm sure your machine body is grounded so you should not get shocks from static discharge by touching it.

Static discharge current could be flowing through the motor's shaft, bearings, and into ground. My guess is that if there are sparks, they occur millions of times a minute. If the motor hasn't failed yet, it is probably fine.

Rick
The spindle is isolated on that machine. The table is grounded. So if you lean over and touch the spindle when running, your body general makes contact with the table grounding you out and you get a big shock. If machining plastic you can get a shock probably every 10 seconds off of the spindle motor. It's so bad the chips jump off the table because of the charge.