Boy! Color me confused. I'm doing a 3d part, cutting both sides, about 24" X 24" X 3" in MDF. Rough cut with 1/2" ball nose, several passes to get down to finish. First side went fine, perfectly smooth movements on all three axis simultaneously. Drawn in Solidworks, tuned for cutting in Rhino, IGES export out into Mastercam for first side. Back into Rhino to flip the part to do the other side. (My Rhino is better than my Mastercam). Used the same tool paths as for the first side, just reset the geometry. Now for my problem...on the back side any time I have a direction change in either X, Y, or Z it jerks through it in small increments, then proceeds to a normal speed cut on the straight cuts. Conservative speeds - 100ipm on the XY, 45ipm on the Z. Shopbot PRT96 with upgraded control box running Mach3. Rackin' my brain and I can't figure what could have changed. It acts kind of like ramping is totally missing. Any ideas?
Donn