We run our laser on Lightburn.
It has started cutting exact copied objects different sizes, which completely baffles us. Like 5 mm difference in an object that 12 x 21 cm, which is a massive difference.
We dont know what to do.
Start by sending the file or another file with similar problem.
Pictures and job details (settings, orientation, bed placement, workspace layout, etc) are always helpful, too.
With not much to go on, I’m calling it a mechanical problem of some type.
Hi there,
Its a .ai file that does not want to upload to here.
Save as a Lightburn file, complete with all settings as you run it, and upload the lbrn2 file. That’s far more telling than a graphics file anyway.
Hi there will do soon as I get back to the office. In the meantime we tried checking the X and Y axis settings on Lightburn, cutting small squares to check, but horizontally, it stays 2-3mm longer than it should be.
Longer on both axis? or just Y
If just Y , any chance you set Rotary to Enabled by mistake?
While not especially helpful in this instance, you can upload most file types by appending “.txt” to the end of the filename. For future reference.
ie. “filename.ai.txt”
SCC A5 Journals 1pc.ai.txt (3.7 MB)
Hi there I quickly tried to upload on the fly as you advised.
Hi its just the axis that goes overhead left to right
…not to be artificial, but I would prefer to ask for the file that gives you the difference in the result, the actual lbrn2 file you use after you have imported the ai file.
SCC Journal.lbrn2 (576.3 KB)
Hi there. I continued trying to try new setting with the calibrator settings, but nothing has changed. I took a short video of the original design on the laser bed, then framed the file to see how much bigger it makes it. The height (Y) seems okay, but the width (X) is about 1cm bigger.
Still can’t seem to fix the problem. On my file you’ll see stitiching holes, for some reason there is no ‘glitch’ when it comes to those holes, but somehow it is adding additional holes to accompany the ‘new width’. So instead of it being 333mm it is over 340mm. The first 2x came out exact to size, then now it all changed. Every time I laser cut a new piece, their sizes are different to the previous one… it’s happened before on another design. I had around 40x of the same design to be cut-out and engraved, when I took them off the laser bed, about half of them were longer on the one side of the symmetrical design… no clue what happened. I thought maybe it was because there is too many for the laser to do, so i did one by one, and still now it’s happening… any advice will be highly appreciated!
You mix things together that complicate the matter.
We need to try to go systematically.
- Is it an LB project problem or a mechanical problem you describe?
- Mechanical problems must be found first and solved.
Draw a square 200x200 mm or if possible, as large as you can. Measure that result as precis as possible to determine if your x, y axes/steppes are correct. Is it ok then we can look at your LB project.
My quick overview of your file couldn’t find any special error, however, I will “construct” this plate somewhat different, e.g. Do I want to trace your pictures when they are so easy to convert.
Without user intervention, software like this most generally won’t change output. Communication problems (cables/wireless) can cause all sorts of unpredictable things. It may still be a setting causing a hardware/mechanical variation, but it still seems most likely a mechanical fault like a loose pulley.
I won’t be able to look at the file for a several hours. I’d imagine others will have a raft of suggestions before I can even download it
Hi there,
Maybe more background will help you to help me.
We have a diode laser on a cnc rig 1m x 1m. been working well for about 2 years now cutting thin leather. Heres a picture of it.
I have kept on testing. I removed and cleaned the belts all three and put them back and tensioned them.
If I draw a square, it still makes the X axis side longer. 60 x 60 mm square, I get 60 Y x 65 X mm. X axis for me being the one raised above the bed, to which the laserhead is attached, going left to right in the picture.
Then your steps for x no longer match, strange…
Can a failing stepper driver cause this? Perhaps swapping drivers between axes would be revealing…
would more likely be either:
a different resolution stepper motor, a different sproket setup between X and or Y
Rotary being on
Or… some miss configuration of steps per mm
$$ should clarify between $100 and $130
Belts and all that seem well tensioned even in the bigger machine
The only other thing i can think of is some drag on the Y axis caused by the Chain. but that woudl be my bottom of the list
Couldn’t You test with an axis calibration?, it only takes a few minutes and is fully reversible.