Graphic Distortions in Fill on Rotary

Hi All,

We’ve been running etchings on a rotary. Recently a logo came up that has been giving us some trouble. There are striations in the graphic that could be due to skipping/slipping on the rotary, but the main issue is that the etching keeps continuing into areas that should not be shot, and seemingly in-line with other other lines in the graphic. In the attached photo, the bottle/rotary was aligned with the X axis so the long verticals of the graphic were aligned with the x-axis.

Any ideas?



Treblab Logo

I’m not sure if I’m following the problem statement.

I’m interpreting striations to mean the vertical gaps and shifting in the burn. If that’s right then we’re on the same page. And agree it’s most likely due to slipping/shifting.

This is where I think I’m missing it. Do you mean where that the line edges are not crisp and look frayed?

If so, I suspect it’s because the quality of the graphic image is fairly low. You can see that the edges of the graphic are fuzzy. Additionally I can actually see what looks like a vertical shift in the graphic when zoomed in (near the right third of the image).

Can you get a higher quality image or vector? Or possibly convert this to a clean vector?

Assume you have multiple copies on mugs?

It does look like skipping in the rotary.

If I’m reading you right, that movement is from the Y axes.

I’ve had that issue a few times and worse with mugs that don’t ‘stick’ well to the rotary along with mugs that are ‘heavy’.

I have my Y acceleration set very low along with the Y start speed. Start speed is how fast the machine will attempt to start the y axis movement from a zero speed. If I need to I will load my rotary configuration file, but they are single digits.

After that, I’d look at sticking the mug better to the rotary. What kind of rotary do you have…?

I don’t do vector cuts with mugs, they always seem to skip and you have no speed control.


The image of the logo might look that way because I uploaded a quick screen cap to show what the logo is meant to look like. The little blue arrow in this image is pointing to the part that I can’t figure out. The verticals, which were aligned with the x-axis, continue just past the diagonal lines, beyond where they connect.

Even stranger is that it seems to occur at each of the verticals. It’s as if the laser is for a fraction of a second longer than it should before cutting off, but it doesn’t do it consistently anywhere else.


I hadn’t heard that about vectors causing issues. I’ll try converting to a raster image and see if we get any different results!

I had thought the artifact that you highlighted was a result of the shifting. If the line had been positioned correctly adjacent to the other portion, it doesn’t seem like it would look overextended.

I’m curious about the edge fringing now since you’re saying this was originally from a vector. Let’s see the results of the converted image…

I can see the scan lines in the cup… so this is a fill or image…

If I understand you, the photo has X axis orientated in the Y direction…?

So the scan is up and down, along the X axes…?

I’ve seen that effect, I believe, the engraving is shifted, but returns to it’s proper place.

Do you mind posting the .lbrn2 file so we can look at what you are doing?


Well, I just don’t know what to say. Using a raster image did the trick. The anti-aliasing is rather noticeable close up.

I was kind of disappointed that vector engraving was as difficult as it turned out to be. Such is life…

Glad you got it worked out…

Take care


That’s great.

I’m curious, though, do you actually see those exact stair-steps in the raster image? I’m particularly curious about the wavy edges on the lower left. That seems like it could be something else.

You don’t see the anti-aliasing in the source image. The raster image is quite clean. I saved the vector file as a 600 dpi png for the raster source file. I think you’re seeing the limitations of my beam kerf. This is a run of the mill 2.5" tube with a 63.5mm focal lens. No special high-definition lens for this setup, which I imagine would produce finer results.

It looked similar to the issue described in this topic. Might want to take a look and see if it fits.

That really does look like the item is slipping on the rotary. The way jobs are built up and sent internally, by the time they get to the output code, there’s no significant difference between a raster job or a vector job.

Double check that all the settings were the same, and you’d really have to do a few more runs with the vector file to make sure it wasn’t just a one-time hiccup.

I would normally agree with you, but we’d run several tests with the vector before trying converting it to a raster file. And at this point we’ve shot 15 perfect bottles with the raster file. 0 failures.

I don’t think I’m experiencing the same issue as in the other thread. Here’s a zoomed in view of my preview. I’m running a fill here, where the other thread is seems to be fine tuning settings to eliminate some imprecision at the beginning of a stroke following a rapid translation for a line etch.

I see what you’re saying but I believe the other topic was also doing a raster pattern. There was no attempt at trying to curve the laser around the corner. I’m not familiar with the setting changed and was surprised to see the result which is why it jumped out to me.

Do you get the same stair-step look on flat material? What LPI did you burn the mug at?

If you do, this is worth review, Scanning Offset Adjustment - LightBurn Software Documentation

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Y’know, I haven’t ever really had issues with vectors on flat material. This might be the second or third time I’ve ever had to run a raster, and only because the vectors were giving me issues on the roller.

LPI was 0.080mm

Oh my, thanks! I think this may solve several issues I’ve been having. I will definitely report back on how it goes.

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Looking at your file again, the thing that stands out to me is that each of those gaps occurs immediately after one of the vertical filled parts, so it’s possible this is a bug in the code that converts vectors to raster fills.

Can you email the project file to, so I can try to reproduce this? (Include a link to this thread so we know what it’s about)