- Dan, Not the only way to get the lash lower, but a great way to do it is upgrade to our precision leadscrew set and extended travel Z column. We use KerkMessage 1 of 5 , Apr 14, 2009View SourceDan,
Not the only way to get the lash lower, but a great way to do it is upgrade to our precision leadscrew set and extended travel Z column. We use Kerk Motion precision leadscrews that are far more accurate than stock along with their NTBF anti-lash self compensating nuts. Heck, throw in our extended X and Y and people describe it as an entirely new and more capable machine.
Pictures and video at http://www.a2zcnc.com/a2zcncmonstermill.htm
While people may tell you they do better than .005" on the stock setup it is hard to achieve and almost impossible to keep due to the rapid wear of the little brass adjusters when run on CNC.
A2Z CNC division
1530 W Tufts Ave Unit B
Englewood CO 80110
- I will concur with Tim s statements on the Kerk leadscrews, and the anti backlash nuts from A2Z. The single best upgrade to my mill since I started machining.Message 2 of 5 , Apr 14, 2009View SourceI will concur with Tim's statements on the Kerk leadscrews, and the anti backlash nuts from A2Z.
The single best upgrade to my mill since I started machining. The factory lead screws and adjustments are OK for manual machining, but cannot hold true for long CNC intervals.
I cannot say how many times I began a project, just to have something un-adjust, slip, or collide due to the old setup. Now, it runs so smoothly, at nearly double the feed.. all while running the motors at lower RPM's (much more torque).
My machine has been running all night, and is still going out in the shed. The performance just can't be matched, and the up side is that I've got so many upgrades to the Sherline, I only need a couple more parts to make another manual mill for a backup.
- Another option on backlash: I was trying to mill a PC board for some .65 mm surface mount chips. Backlash was killing me. I measured it to be .004, .005, andMessage 3 of 5 , Apr 14, 2009View SourceAnother option on backlash:
I was trying to mill a PC board for some .65 mm surface mount chips.
Backlash was killing me. I measured it to be .004, .005, and .006.
After reading a lot of stuff, I decided that trying to adjust that out
would just lead to further wear. So I tightened it up a bit, but not
much. Then I added the BACKLASH= for each axis to the EMC2 config file
(I am not sure if EMC1 has this). With these backlash compensation
values set, I then measured the backlash again. then I tuned the
backlash values again measured with the compensation. Using this, I was
able to get .0005 repeatable values in direction changes because EMC2
would "take up the slack". I know that this may not help on deeper cuts
if the cut moves the board, but EMC will make up for it.
Perhaps a combination of the precision lead screws along with emc2's
backlash compensation would be the best plan. But if you do not want to
upgrade the leadscrews right now (maybe in the future for me, at the
moment I have more pressing upgrade requirements), the backlash
compensation is a good choice and helps lot! -Chuck-