[SOLVED] Path deviation between Profile and Path from shape

[RatonLaveur]

Hi guys,

I found an interesting artifact today trying to generate a tool-path for a small feature.

Using Profile Based on Face or Profile Based on Edges, the tool-path deviates (validated deviation in NC viewer.

Using Path Based on Shape seems to work accurately, so I don't think it's a mesh or actual model problem. Perhaps the Profiling operation makes simplifications in the code? Interestingly the deviation reverses itself when using compensation outside or inside.

Anyway, I found that interesting

EDIT: 27.05.2019
Shameless bump, because I feel like this may touch on something important.
And I add pictures to better explain the deviation from shape I have noticed.

The last picture shows what happens if I use "Path From Shape". Where the whole wireframe is pathed, but it is accurate.

[RatonLaveur]

Shameless bump, because I feel like this may touch on something important.

[GeneFC]

This problem has been around in one form or another for quite a while. It is not really a bug, but rather an often ignored preference setting. The path curve generation uses precision and tolerance values to determine how closely to follow the original model. Too tight and the gcode file gets large; too loose and the effect you see becomes apparent. This is especially true for small features.

Go to Edit >> Preferences >> Path >> Job Preferences

Set tolerance and accuracy to smaller values.

If you hover over the path it can be seen that the straight section near the end of the slot is ignored and the entire path is simply an arc. After shrinking the tolerance and accuracy the path will look correct.

Gene

[RatonLaveur]

Gene,
Will try tomorrow. It's true that the model is very small (width of 0.1 to 0.2 mm) but then again this is sometimes what I machine.
I had tried the meshing accuracy but not the one hidden in Job.
Thanks a lot!

Edit: tried and succeeded! marked as SOLVED