madmachinst
Stainless
- Joined
- Jan 15, 2007
- Location
- Central FL
This here is a retrofit and I did all the new electronics with machmotion controller 750 Watt closed loop servos. They have a calibration app where I put a DTI in my quill set it to zero off a 4" gauge block and then command a move( 4.007"), then I input into the screen what the move actually was, and that tells the machine how many steps per inch on that axis. Servos have like 10,000 PPR or something like that and between lead pitch and pulley ratio 10 rotations equals an inch. Now my problem is that throughout the axis' I have different steps per inch. One spot in X it can be 100,070 in another it can be 100,550 and so on and so on. OK, the machine is from 1991 ( last 5 years sitting in my garage collecting dust), but it is supposed to have NSK ballscrews and I also changed the regular bearings some stupid maint guy threw in there to thrust bearings when I originally retrofitted it back 5 years ago. I had decent accuracy back then only electronic problems, now with the machmotion system, electronics are better, but mechanically speaking I am getting different steps per throughout my axis motion. I haven't even started on backlash. ON Z axis I am getting like .0025" difference between 2" move and 4" move. driving me nuts. I was going off a parallel laying across the table. If I get screw mapping on this thing, you guys think I can rely on the knee to go down .25" increments and map that in the controller. Thanks for all the help.
Sincerely,
C. Wizman
Sincerely,
C. Wizman
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