Haing some serious trouble with lightburn and a new laser. We’ve been running our old CTC 650x450mm laser cutter without issues, until the laser wore out and we had problems replacing it to the extent that ax replacement machine was necessary. It came with lightburn.
Our designs are all dxf files. We import them to lightburn and they look perfect on screen but not when cut. Shapes are mostly correct, but in the wrong place. We have an offset “down and left” of about 2mm on some shapes. This is unacceptable for our product as tags have to alone with holes etc and any misalignment is ruin.
We’ve tried making the file simpler and it does seem to work then…but this isn’t an acceptable solution as we are known for our detailing.
I realise all the details of the laser are not complete…I will address this over the next couple of days. But can anyone suggest what might be wrong?
We have success, which frankly I am surprised at but extremely relieved!
ONE simple parameter change in Lightburn was all it took; change “PWM rising edge valid” from “False” to “True”. This single change has restored our output to perfect accuracy.
Not quite I’m afraid. Our Ruida 6442 controller is in a second hand HPC Laserscript LS6480 Pro machine, so no guarantee it hadn’t been tinkered with before.
I thought it might be helpful to see the problem and the fix.
The image that looks like you’ve had too much beer is the problem…once your eyes get used to it (zooming in helps) you can see the “southwest drift”. In the other image the “6x” in the images indicates we cut the pattern six times in place. The one on the right (edit: or thanks to my phone, the upper of the two) is after we set the “PWM RISING EDGE VALID” to True on both the X and Y axes, and though I forgot to write on it, was also cut six times in place…
BTW we found this answer on another post in this forum, and they mentioned in passing that their Ruida software didn’t have the problem…so maybe the fault lies in default Lightburn settings rather than the Ruida controller? I don’t know, I’m far from an expert in these things.
Ah: so it’s new to you, not new new. Now we all know. :
Nope: the Machine Settings live in the controller’s nonvolatile memory; LightBurn just displays what it reads.
An incorrect Step polarity (or two) doesn’t produce visible misalignment on all jobs, so it can hide in plain sight for years before consistently wrecking That One New Design. The previous owners may never have discovered the misconfiguration because their layouts never produced a visible problem.
And, of course, when it ain’t broke, don’t go fixing it!
The problem depends on the exact path of the laser head through the design. I suspect different LightBurn Optimization Settings would change the outcome.
If RDWorks traverses the same design differently, which is almost certainly the case, then it will not (perhaps “may not”) trigger the problem.
Other designs will trigger the problem in RDWorks, but you don’t find many folks around here using RDWorks consistently enough to encounter that situation.
Like I said, I’m not expert and it sounds like a lot of comparative testing is needed to really bottom it out. Most people (us included) are too busy filling orders!
