Homing issue.

[ian-mellin]

Hello,

I have an issue that is causing me an issue when I home the machine.

What works correctly.

The Z axis is homing correctly

The X axis is homing correctly

What is not working correctly is the 'B' axis that is slaved axis 'Y'.

What I have tried. I have removed the X and Z axis from the homing sequence to narrow down the issue as I know they already work.

When I home the 'Y' axis the both the 'B' axis and the 'Y' axis move in the same direction, the issue I have is that the 'B' axis is moving quicker than the 'Y' Axis causing the 'Y' axis to twist.

As 'B' is slaved to 'Y' I don't understand why the both Axis's don't move at the same speed.

My machine uses a belt system with 1:10 gearboxes. One gearbox driving each axis respectively.

The tension on the belts when I listen to the twang is the same, so I know the belts are tight enough. On the odd occasion that I have managed to get the system to Home correctly then the 'B' axis does as it is supposed to and follows the 'Y' axis as it is slaved.

It would seem that until the system hits the hard limits on the 'Y' and 'B' axis that the actual slaving does not come into play. How can I make the 'B' axis do the same as the 'Y' axis at all times.

The B Axis moves quicker than the Y axis even though they are set the same.

This issue is cause me sleepless night's as I have tried several combinations of settings.

Please find attached my Zip file with the setting.

 

[tmtoronto]

Is it possible to switch the B and Y axis cable connections and see if the speed difference moves to the new stepper motor or remains the same as it is now? It may help determine a mechanical vs electrical issue. Discussions in other forums mention reducing overall acceleration and homing acceleration, increasing step frequencies, checking cabling and especially avoiding ground loops and EMI interference. I am new to CNC so have no real-life experience of my own yet, and likewise would not be able to provide feedback on your settings.

 

[mikko]

I use V4.02 and have similar problem. Masso lost that slaving.

 

[ian-mellin]

Hello,

Thanks for the suggestion on switching the wires on the 'B' axis and the 'Y' axis to see if the drives not working correctly. This has no impact at all.

I did however find the issue, it was down to the dip switches on the motor driver being switched that shouldn't have been. This caused the one axis to rotate quicker than the other.

Kind Regards

Ian.

 

[tmtoronto]

Thank you for sharing the follow-up, it is helpful information for us all. Happy also that the issue was resolved.

I am curious as to why switching the cables had no impact, when it was the driver setting on one of the drivers that was the issue. I would have thought that the speed issue would have followed the driver, and therefore the other stepper motor would have shown the speed anomaly.

Tom