i turned a cylindrical part and measured runout in the chuck using a 1µ mitutoyo with a large radius tip and turning chuck by hand. i saw 1-2µ. great. then i measured it with spindle running at 25 rpm. 11µ. hm. thinking vibrations. disengaged the gear and let the machine run. no movement. turned spindle by hand and got 1-2µ again. got a 2µ graduated test indicator with a 3 mm tip and it shows 12µ.
1. whats happening? do fine vibrations transmitted to the mitutoyo make it show correctly by eliminating hysteresis?
2. guessing that 11-12µ was what it actually is i tried adjusting the plain bearings wihout any success (turned another piece). how bad do you thing this is? (lathe has 370 mmm swing.)
1. whats happening? do fine vibrations transmitted to the mitutoyo make it show correctly by eliminating hysteresis?
2. guessing that 11-12µ was what it actually is i tried adjusting the plain bearings wihout any success (turned another piece). how bad do you thing this is? (lathe has 370 mmm swing.)