Two successive contour passes with different tolerances causes bad path

For example if I run a contour pass with a tolerance of 1mm and then run another contour pass with a tolerance of 0mm the second one does not follow the object at all. Here is the exported workspace:

Hi @Jakek and welcome. I tried to download that workspace, but it was deleted. If you can provide another, I would like to troubleshoot this. Thanks

Here’s a better link

that is a really interesting failure mode. I’ll see if I can’t fix it for tonight’s release.

thanks for the bug report.

@Jakek I have a fix for this for tonight’s release. However, I notice the only difference between the two contour passes is the tolerance setting. The values you have in here (1 and 2mm) are quite coarse and will not produce the results I think you’re looking for. This is not the same as leave stock in roughing. Using values this large will result in the removal of material you don’t want removed. This is visible in the preview (with the bug fix).

Typically with contouring you would use an X and Y pass. If you want to improve the look with two or more Y passes, I would recommend leaving the tolerance at 0 (meaning auto generated) then change the step over value between the two operations.

Thanks Stewart that was fast. And thanks for the clarification, I was misunderstanding the purpose of Tolerance.

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