Question Suspicious milling glitches.

Recently my S420/2 has thrown a wobbler 3 times when executing one particular file generated by CUT2D.

The single file concerned is a profile cut out of a 10" (MDF) disc with 16 equispaced radial slots. When setting up the 3mm tool parameters, the feed was inadvertently set too low, so when actually executing the file under UCCNC the feed was jogged to 150% on the "RUN" screen.

The malfunction on two occasions resulted in corruption of all three axes reference data, and on one occasion the sense of Z-axis increments appeared to be reversed (i.e. the tool was raised between passes rather than lowered). These faults all occurred when the feed was adjusted to be above 100%. and when the code defining the radial slots was being executed. The only damage was an attempt to mill through a holding down screw - needless to say the screw won.

Testing the file several times at 100% feed rate doing an "air cut" showed no untoward corruption of position, so presumably the GCODE produced by CUT2D is correct and above suspicion. Could it be that the combination of a radial slot GCODE sequence and greater than 100% feed rate upsets UCCNC in some way??

I should add that my S420/2 has never shown these symptoms on any other occasion and has been totally reliable up to now. The profile cut I required was split into two files - one defining the radial slots (pocket file) and a second defining the disc only (profile file). These executed faultlessly.

I have retained a copy of the suspect file for further investigation if required

Peter H