Offset issue..offset of a circle isn't round

Has anyone else ran into this before? I used the offset tool to create an offset of a circle. The offset it creates is not perfectly round or curved like the original circle. Is there something I’m missing or could this be a software problem?

What is the radius of that circle? By the looks it could just be displaying incorrectly but may be mathematically correct. ?? How does it cut?

Looks fine to me. What offset options are you using?

The diameter of both circles is 25. The red “circle” is the offset from a smaller circle (about a 2-3mm offset, I can’t remember the exact number). The blue circle I made using the ellipse tool. I selected both circles and centered both vertical and horizontal axis.

I did not cut the offset circle.

Yep, I see what you’re talking about here. Interesting. @LightBurn will reply as soon as he can, I’m sure. My guess is it probably has something to do with the small scale.

Also, it doesn’t make a difference if you switch to smooth or coarse rendering.

For extra reference, my offset options are as such:

These are my offset options/settings.


The offsetting engine in LightBurn uses line segments only, so all objects are converted to lines first, then offset. If you have ‘Optimize / Simplify results’ enabled, arc recovery is performed after the offset, and this usually results in “correct” circles again, at least within the specified tolerances.

In the image you show where the result is lines, none of the resulting offset lines get further from the ‘true’ circle by more than about 0.02mm, which is well below the accuracy of your laser.

With the ‘Simplify result’ option enabled, the output is within 0.005mm of the manually edited circle:


Thank you for the explanation.

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