Its not a specific Lightburn related query I think its more related to the machine.
I am running a HPC 6090 with a Ruida controller 6445G(I think)
For a little while now I have been experiencing some mismatch on the line and fill settings and it usually becomes apparent on larger batch prints where the laser moves further away from the homing point (top right). To me it doesn’t seem to have a specific point where it starts to drift out of sync with each other because when I have previously started a 900x600 wide batch of engraved/lined the mismatch between engrave/line has become noticeably apparent at the far left of X, same for bottom of Y and left of X, as it moves back from these points to the homing point it gets better and worse across the whole work piece.
If I do a one piece engrave or line and cut item close to home this issue doesn’t seem to be as noticeable. That said anymore than one item it starts to become apparent ever so slightly. See image:
Previously I have had to replace a stepper due to the age of the machine on the X axis however when that started to fail it became very erratic during engravings. The only issue here is my engrave and outline are drifting apart.
Just trying to figure out what it could be as apart from this minor issue and running smaller batches the machine is ok! Will post my setting file up when i have time the machine is currently being moved into a workshop.
PWM rising to false on both axis so I am going to set them opposite for both axis sequentially and test individually.
Belts look like they have teeth
Currently in the process of moving the machine to a workshop so once its back up and running will run a few files that have been known for mismatch at the extremities of the work area from the top right home i.e. Top Left, Bottom Left, Bottom Right.
Long time taken to check this, however I think I have found the problem, after moving the machine I have run some test files.
PWM rising were both set to on, which was in the original machine settings as provided to me by the manufacturer so after some tests with and without these on I think it was not that.
Scrolling through my vendor settings I came across my bed size was slightly larger than my work area i.e. 900 x 600 was set to 900 x 610 I think this has been the issue however I am starting to use the machine again now it has been moved and will monitor as I go.
That has no effect on the problem you have described.
If the controller thinks the Y axis is 10 mm longer than the physical travel limit, then the gantry will smash into the frame on the end of the Y axis rails farthest from the home switch; correcting that is always a good idea!
Having though about it, it wouldn’t make much different to the two shapes interacting with each other during different layers.
The X axis was the dimension that was out but that would just mean my step count was off and my shapes would be wider? No gantry smashing on the machine I’d safely say I have 25mm either side of the 900mm X axis before that happens.
Setting PWM rising on or off on either axis, I didn’t see any mismatch when I did samples at the furthest points from the home (top right) to top left, bottom left and bottom right.
I think next time I’m running it will run the array I was having issues with on some card at full size and see if a mismatch occurs.
The limits you show are 10 mm too large on the Y axis, which is why I started there. Fill layers should be scanned parallel to the X axis, particularly on gantry CO₂ machines, but I’ve used 90° layers for special effects.
On Fill and Image layers, Ruida controllers compute the overscan region based on the axis speed & acceleration limits. If the Max Travel for the axis exceeds the physical limit and the overscan extends into that region, the controller will smash the head into the frame, even when the geometry lies “safely” within the (incorrect) boundary.
Always tell the controller the truth.
That symptom is triggered only by specific motion sequences (and can go years before that sequence happens), so the only way to tell is to:
Run a job that fails in that specific way
Flip one of the PWM Rising Edge Valid settings
Run the same job again
See if the result changes for the better
Basically, there are no standard testcases, but the usual stepper driver connection requires those switches to be set False. That some machines get shipped with incorrect settings somewhat dims my cheerful demeanor.
