Yesterday I lasered with my X20 Pro a very large image (645x360mm) for the first time.
The image is offset by about 6mm to 600mm!
I have been able to isolate the problem, what is not a mechanical problem.
If I cut the outline DIRECT after engraving, without homing between, the cutting line is still the correct one.
**
**
Lightburn produce an incremental gcode for engraving.
So the offset by line must be app. 0.001mm.
It can only be either a firmware problem or a software problem by lightburn.
But if I control the Gcode I can´t recognize an error, what is difficult because ist incremental
I could only find a possibility to send absolute coordinates by vector cuting, but not for engraving.
Can I give the gcode out to the maschine as G90?
Perhaps by Start macro?
What do think is the problem? Lightburn or Atomstack Firmware?
And much more important How to fix this?!
Hi Josef, are you selecting all the project and burning, cutting all at the same time or are you doing the burning then doing the cut?
Does it look right in the preview ?
Hi Chris,
thank you for answering!
Could you load the second video?
Here you can see the cut is at once after the engrafing, without homing between
The Preview is correct
Hi Josef, sorry didn’t watch the second one but now, seeing it, the propeller looks to be where it should be (looking at your preview in the vid), the rounded parts at the bottom look to be the same as the preview.
The rear part (top in your preview in the vid) is way out.
That’s a strange one.
Sorry that’s got me stumped.
Hopefully someone will come along and give you a solution.
I think it is a firmware problem, but the solution would be simple, if every first line of engrafing was by absolute coordinates.
I wrote this to support, hopefully they will help me…
Josef
I don’t understand your reasoning here. Offset is 99% a mechanical issue. If you check the preview window and everything looks fine there, it IS a mechanical issue. I also don’t think it’s a firmware issue, we would have had many more reports on this already. I don’t remember one (doesn’t necessarily mean there wasn’t one).
Can you elaborate a little more, why you think it’s not mechanical?
I have tested various speed for engraving -9000 mm/min with absolutely the same result.
Should be not at a mechanical problem
If I edit the gcode file by hand (every line X-0.001) I get the right result
Josef
I´ve tried to burn the edited (Offset X-0.001 in every line) gcode file in LaserGRBL
The result is now an offset to X-???
I made two new tests
One vector stripe 600x10mm , built directly in Ligtburn
and a Halftone picture in Photoshop with small color gradient.
Both are burned perfect… I´m really confused!
Now I will test the original exported big picture with LaserGRBL.
It remains exciting
It’s worth noting many people have insisted their machine cannot possibly have a mechanical problem, so the solutions must involve bizarre software or firmware workarounds.
In most cases, we eventually read that they found a loose screw or stripped belt, fixed that, and the machine works perfectly.
In rare cases, we read that the controller’s firmware has errors corrected in a more recent update.
In general, however, when the machine cannot dependably position itself according to the controller’s commands, the problem involves a loose screw in a pulley or coupler, a misaligned / badly tensioned belt, or a similar mechanical issue.
Sometimes, it will be a speed or acceleration setting beyond what the machine can handle, perhaps chosen in an attempt to improve the performance. If you have not recently changed any of the controller settings or added a much heavier laser head to the machine, this is unlikely to be the problem.
So IMO the solution to your problem does not require editing G-Code or looking for software / firmware hacks. It requires finding the mechanical problem causing the errors. Looking elsewhere only delays finding the solution, which will require careful and patient examination of all the hardware than can possibly cause the problem.
I´ve checked the belts and then tested them with different tensions.
First I made them tighter, but then there was a fairly large mechanical offset.
I adjusted the guide rollers so that they were just tight enough not to wobble.
The belts so that they come back immediately when pressed down.
The first and last piece are identical, the complete row is is on the same level (The very first row is a bit scaled)
This job is running perfect, everything as it should be.
If the offset is due to a mechanical problem, why is it no longer there when cutting (at once!)?
And shouldn’t there also be an error here?
What else could be the cause?
Do you have any ideas? I am at a bit of a loss
As well the mechanical stuff Ed mentions, don’t rule out inconsistent homing. My 5W machine shipped with extremely aggressive homing speed settings and was not as consistent as I wanted until I slowed it way down. In my opinion, there’s absolutely no need to home quickly. I will quite happily trade an extra 10 seconds for an absolutely accurate home position. I typically only home once per session. Once per job if I have extended idle time or change jigs between jobs.
Speaking of which, some machines also drift and lose position once the steppers idle down. You can set $1=255 to disable stepper idling if this is a concern on your machine. Values below 255 are milliseconds…so $1=250 is a 250ms (0.25 sec) delay before steppers power down.
of course I can, thank you for your help!
But I have some new confusing news…
I´ve tried graving in LaserGRBL with pass trough too and it seems that the image burned correct, terrible quality but correct, I think (I´ve burned on glued onto wood papersheet, because running out of wood )…
How did you do this? Was this done in two operations?
In your original post, the Junkers puzzle piece, was the engraving and outline cut done in a single job? Or was that two separate jobs?
Also, are you exclusively using millimeters as units or do you ever switch to inches? I assume you don’t use inches based on your language settings but good to confirm.
In this example, can you confirm whether its the outline or the engraving that’s actually offset? Also, can you confirm that it’s just offset? Or is it skewed? I assume the latter. For example, the engraving is slanting slightly but consistently.
How to fix this?!
)…
