Centroid Community CNC Support Forum

grossmsj wrote: ↑Mon Aug 26, 2024 7:20 pm

johannes wrote: ↑Sun Jul 21, 2024 2:47 pm (remember to clear the memory of precision hard stop homing in the Clearpath software each time you adjust). You then get super repeatable, square gantry each time.

Agreed it is really accurate and dependable. The only glitch I've run into is an occasional (once a month?) situation where my Y-slave motor will back off too far during homing. It's easily observable and I can even hear how different the motor sounds. Clearing the precision homing selection corrects the problem. After having this happen a few times, I just turned off the precision homing option for both Y motors. I haven't seen any loss of accuracy nor have I had the problem occur again.

great info , thanks for posting. i did observe the same thing at least a few times!

cnckeith wrote: ↑Tue Aug 27, 2024 9:58 am

grossmsj wrote: ↑Mon Aug 26, 2024 7:20 pm

johannes wrote: ↑Sun Jul 21, 2024 2:47 pm (remember to clear the memory of precision hard stop homing in the Clearpath software each time you adjust). You then get super repeatable, square gantry each time.

Agreed it is really accurate and dependable. The only glitch I've run into is an occasional (once a month?) situation where my Y-slave motor will back off too far during homing. It's easily observable and I can even hear how different the motor sounds. Clearing the precision homing selection corrects the problem. After having this happen a few times, I just turned off the precision homing option for both Y motors. I haven't seen any loss of accuracy nor have I had the problem occur again.

great info , thanks for posting. i did observe the same thing at least a few times!

Just speculating, but could it be related to not having a firm enough hard stop?
On my machine, there is a 3:1 belt reduction (one turn of the motor rotates the ballscrew 1/3 rotations). This ends up equating to a relatively short physical axis travel for 1 motor revolution. And I believe the hard stop needs to repeatably fall within a single rotation (the same index) for precision homing to work.So if your hard stop is too squishy, could it sometimes end up outside the boundary of that 1 rotation???

yes you are correct needs to be within once rotation, less is better and squishy is not!

johannes wrote: ↑Tue Aug 27, 2024 10:11 am So if your hard stop is too squishy, could it sometimes end up outside the boundary of that 1 rotation???

My turns ratio is a little over 1. 6400 steps per revolution.
The proximity switch is not activated.
When this isn't working as it should the gap left is about 1/2 inch more than you see here. I've gotten the impression that the value stored in precision homing has been corrupted.