Getting a strange loss of zz

[GeneMpls]

I am machining some acrylic and when I send a file with a round over bit
(also tried with a 90°Vbit) the xy goes to the start point and then drops
briefly and then the machine loses its ZZero- and continues with the file
over the surface. It is just a peck and then up .25 or .5 up and then moves
on. I have recalculated and everything I can think of. I will try to add the file from edit. It happens between the J3 and M3 commands at the beginning. Thanks Gene

[Brady Watson]

Make sure your Z has enough travel to go the full depth before hitting the mechanical stops. Otherwise it will hit the stops, stall and lose position. Same would be true on very thick material where you mechanically top out the Z because your safe Z height is too high.

-B

[GeneMpls]

Excellent thought -as always - thanks Brady- it's about 90° in the shop now but I will try that in the morning. Thanks Gene