If it it cuts fine at 10 minutes and goes off course at 2 minutes, everything else being equal?, it would seem something is loose/and/or flexing. Maybe try a few other shapes requiring similar movements using the same speeds and DOC just to see what happens? Machine have a good history with few issues?
Ok, just tried the 2 min cut in different material and am betting the same result. Problem with my 10 min cut is I didn’t save it as a project. But i can open the gcode file, what line or code is speed rate? If I can find this out I can copy it.
James
Check the tightness of the bolts holding the spindle on. Looking at your picture, it looks like you’re getting a ‘rounding’ when the bit changes direction. I’m thinking it’s still flexing somewhere in the machine.
Slow your feed rate down and see if it still does it.
Ignore all of this… you said a bit higher up it does it in a different material. What was the other material you tried in? Pink foam?
Looking at the outline on the stock, I’m also leaning towards what Jeff said… gcode error. Looks to me like it’s running the inside of the contour, not the outside… or some issue with the CAM not using the correct bit radius or sumpn.
Post the gcode here if you want folks to help rule that out.
(Edit… well after reading the whole thread, I now wonder if it is just machine flex. Removing material 5x faster can increase loading substantially depending how it is done. You may have to change your method of speeding up the cut. Just using a deeper cut alone only goes so far. You might try using smaller step downs and increasing feed rate instead.)