Shifting along X and Y axes during rapid retraction

[Sadovshikov_Vitalii]

Using the 2D Contour strategy in Fusion 360 generates a tool path that is shifts along the XY axes during rapid retraction movement, whereas the Bore strategy doesn't shift it. I wonder if such a shift could cause dangerous circumstances, such as the tool pushing the material during retraction.

2D Contour strategy:

Bore stratagy:

 

 

[seth.madore]

Hmm. These values are in MM, right?

A) these values are so tiny, I'm fairly certain they don't show up in the resulting g-code

B) It's possible that there are toolpath settings that are producing this result. Could you share your file here?

File > Export > Save to local folder, return to thread and attach the .f3d file in your reply

[Sadovshikov_Vitalii]

Yes in mm. It also happens in the resulting g-code.

Fusion:

G-code:

 

[seth.madore]

And what post processor are you using?

[Sadovshikov_Vitalii]

Grbl Version: 44066

[seth.madore]

It's a floating point error and also influenced by Tolerance.

I'm curious about your toolpath; no lead-in and out? Just retracting against material is less than idea..

Here's the values with tolerance cranked up:

 

[HughesTooling]

This is an old problem with smoothing enabled. The arc fitting is done after the linking and doesn't line up after.

Here's without smoothing. Don't know why this job needs smoothing as it's only lines and arcs but for some reason without arc fitting the code is a lot bigger. 

[HughesTooling]

Looking closer, the problem is the sketch! The body is made up from just lines and arcs but the sketch is made from splines. 

If I select the body edge and turn off smoothing I get a smaller program and no small error with the retract.

[HughesTooling]

@Sadovshikov_Vitalii How did you create this design? The body is made from lines and arcs but the sketch contains splines. If I extrude the sketch I don't get the same body and the splines don't create cylindrical surfaces and if I project the body I get arcs not splines. So it seems like the sketch and body were created separately.

Body edge is cylindrical.

Sketch is a spline.

[Sadovshikov_Vitalii]

body and sketch from Rhino software

[HughesTooling]

I expect if you use What on the sketch in Rhino you'll find you have NURBs curves or NURBs Arcs that need simplifying before export. Did you import the sketch and body separately or does 3dm import now allow import of bodies and curves?

Mark