Some help with engraving please - I'm not sure what's going on

Hello, everyone :slight_smile:
Can I have some help please! A colleague of mine complained that when engraving small text, the letters came out blurry. When I looked at them I decided that he had not fixed the material and he was shaking. I fixed it firmly and repeated the engraving, but the result was not good. So I started various tests and got here:
I engrave a rectangle with a line spacing of 2mm and as a result you can see distortion at the beginning of each line - when I scanned the uni it was only on the left, if I scanned it would be once on the left, once on the right. If I increase the speed the distortion doesn’t repeat but stretches along the line…
At the same time if I draw lines across 2mm and use Line (Cut) mode - they come out straight.
I tried the same through RD Works to make sure I was eliminating a software issue from Lightburn. The result is the same.
I’m uploading a photo.

Pretty clearly a mechanical issue. The Y axes is wiggling, so something in the drive or optics is probably the cause of this… I’ve seen a head mirror, being lose and a problem with belt tension.

Keep in mind the speed and the possibility of resonance in the system at various speeds. This is greatly reduced if it’s tight or well snugged with the proper belt tension.

If you look at the 100mm/s, next to 1000mm/s, 10 times speed will cause these issues to be ten times longer… you can see it’s still wobbling.

I’d really scrutinize the mechanics…

Good luck


but if it’s a mechanical problem shouldn’t i always have wobbling. In this case, when I cut lines with the same settings, they come out straight. Also, with bidirectional there is wobbling at the beginning of the pass (on the left) followed by a straight line, and the next pass (already on the right) starts with a wobbling and ends with a straight line. If it’s mechanical shouldn’t it be wobbling in the same place!?

If it’s a mechanical problem, you can’t know what it’s going to do… Some circumstances it will be repeatable, but many it’s almost like a random occurrence… This depends on what is lose.

A lens doesn’t move much but can be a real problem to determine that… Many mechanical problems surface like this…


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It does. Those wobbles come from a loose gantry / laser head that’s shaking after the Y axis moves the distance between the engraving lines.

That’s where it moves from the previous line to the current line and begins traveling to the right.

Which is where it moves to the next line and wobbles as it begins moving to the left.

So the wobbles occur on opposite ends of alternating lines all the way across the engraving.

If the mechanics are as snug as you can get them, then the only way to reduce the wobbles is to reduce the Y axis acceleration, so that the gantry does not move quite so abruptly. Whether you can tolerate the reduced speed (because it does not get up to speed as quickly) is a tradeoff.

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