Is this really backlash ?
Posted: Mon Apr 16, 2012 2:21 pm
Hi
I recently installed the new 2012 controller, and am having great success with it.
However, I noticed something that on the face of it looks to me like classic Y backlash, but I'm fairly certain isn't - hence the reason for posting in this section.
The issue initially showed up when cutting some concentric circles (the inner was held with 'bridges' to the outer) - the inner was offset in Y. I tried various mechanical cures with absolutely no effect, so attempted something more scientific.
I made up a rectangular 60mm vertical 'snake' pattern which has has six 10mm segments. The left pattern starts at the top and cuts down. The right hand pattern starts at the bottom and cuts up. When cut, the starts and ends of both patterns are aligned - the segments in between are not !
The first section (bottom) of the right hand pattern is short by about 0.5mm, but both start and finish lines are aligned.
There's also something else that's strange - both axes use exactly the same mechanics (different steppers, but both 200 step) - over 60mm, the X is dead nuts on, the Y is 0.5mm short. Both axes have the same setup in software.
I know the mechanical setup is ok because I have been using it with my lasersaur controller and I have done many tests (I can't change the controllers right now for other reasons unfortunately). It's the same over the whole of the cutting area (1200*600mm).
Any thoughts or magic spelles ? - it smells like software to me
Main board 7.12.04.01
LCD 5.12.02.29
LaserCAD 5.93
I've attached the snake pattern that you can try. Make sure that you DON'T have 'auto order' set, otherwise it won't work - it should start top left, work down to the bottom, hop across to the right snake then work it's way to the top.
I'll posted this across on the lightobject forum in case anyone else there has seen it.
TIA
Neil
I recently installed the new 2012 controller, and am having great success with it.
However, I noticed something that on the face of it looks to me like classic Y backlash, but I'm fairly certain isn't - hence the reason for posting in this section.
The issue initially showed up when cutting some concentric circles (the inner was held with 'bridges' to the outer) - the inner was offset in Y. I tried various mechanical cures with absolutely no effect, so attempted something more scientific.
I made up a rectangular 60mm vertical 'snake' pattern which has has six 10mm segments. The left pattern starts at the top and cuts down. The right hand pattern starts at the bottom and cuts up. When cut, the starts and ends of both patterns are aligned - the segments in between are not !
The first section (bottom) of the right hand pattern is short by about 0.5mm, but both start and finish lines are aligned.
There's also something else that's strange - both axes use exactly the same mechanics (different steppers, but both 200 step) - over 60mm, the X is dead nuts on, the Y is 0.5mm short. Both axes have the same setup in software.
I know the mechanical setup is ok because I have been using it with my lasersaur controller and I have done many tests (I can't change the controllers right now for other reasons unfortunately). It's the same over the whole of the cutting area (1200*600mm).
Any thoughts or magic spelles ? - it smells like software to me
Main board 7.12.04.01
LCD 5.12.02.29
LaserCAD 5.93
I've attached the snake pattern that you can try. Make sure that you DON'T have 'auto order' set, otherwise it won't work - it should start top left, work down to the bottom, hop across to the right snake then work it's way to the top.
I'll posted this across on the lightobject forum in case anyone else there has seen it.
TIA
Neil