cnc class this saturday december 10 at 10am - still have one opening!

Looks like I just missed grabbing a ticket by a few minutes - would it be possible to open up one more spot?

Run away! Run away!

The CNC router Speed controller is not responding properly!

When I press F5, the spindle comes up to the set Speed.
When I start the GCode, the spindle speeds up to 24000RPM!
The only thing I can do is Stop the GCode to stop the Speed over run.

Any prior cures for this?
I’ve restarted the hardware & Mach3 both, to no avail.


I used it yesterday successfully with some help from Jon and Tim. We think there is something wrong with the standard profile being used, so we used a different profile. A theory is that a certain calibration process was used that doesn’t really work correctly and several online sources suggest this can be the cause of a failure like this.

This is second hand information, as I didn’t research this. So anyone who could shine better light on this is appreciated!


I manually calibrated the profile “Test” (which seems to at least get us within 10% of any spindle speeds I tested) which Elly used last night. I also made a post on the mailing list indicating this problem a while ago.