So has anybody else experienced this? I have a desktop hobby CNC so I generally see results within .010 of the designed measurement. I can cut circles, curves and boxes all day and get within .010 except when pocketing/area clearance that contain islands. Actually the depth of the clearance and size of the clearance is within tolerance, but the islands get clobbered to where they're .025 and greater out of tolerance.
For example, using a .1181 bit, I created a file to cut:
3 holes, 2 with islands
1st hole - .175 diameter – measures .181 difference of .006
2nd hole - .5 with a .175 island: .5 hole measures .494 difference of .006, island of .175 measures .151 difference of .024 ????
3rd hole – 1.0 with a .5 island: 1.0 measures 1.010 difference of .010, island of .5 measures .464 difference of .036
The holes are within tolerance, but anything defined as a island gets whacked. The bit isn't too big, is there something I've got setup wrong or doing incorrectly to cause this? Wrecked a couple of parts, because my 'Islands' which were to be pins of a specific size are undersized.