Surface offset causing crash

[keithZ5MNA]

Hi all, newbie coming from Solidworks/Hypermill

I am converting some of my parts over to F360 as a way to learn and I have come across a hang→crash that happens every time.  If I try to do the -0.1 offset around the side walls after the teeth have been modelled in and combined it will hang every single time.  If I do it without the teeth (so it's just a rectangle) it's fine.  

I could get around this by doing a cut extrusion but that's not the proper way.  Am I doing anything wrong that's causing the crash or is it the program you thinks?  Cheers

[keithZ5MNA]

For anyone in a similar situation I was able to get around it by sketching/pattern → extrude the 3 long ways triangles.  After sketch the cutout section of the other face triangle cut then pattern that cut feature rather than the body, after this the offset face worked.

[hamid.sh. · Accepted solution]

I guess it's because of computational load (i.e. Fusion needs to deal with too many faces). When I change pattern instances to 10 along X, Fusion can perform surface offset in a second but it becomes not responding with 15 instances.

I believe you should make a more efficient workflow, e.g. somehow bring surface offset (or the effect) before pattern.

By the way, I changed the second extrude to Join type and pattern to Feature, so you don't need Combine.

[keithZ5MNA]

Hamid, 

Thanks for the update, I also got it to work for 10 only just trying it but later it crashed.  Offsetting before is troublesome due to dimensions of the triangles, doing it after makes the modelling nice and simple.  

Carving it out from the solid rather than making the triangles features has worked however, also thanks for the efficiency tip.

[hamid.sh.]

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@keithZ5MNA wrote:

...Offsetting before is troublesome due to dimensions of the triangles, doing it after makes the modelling nice and simple...

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It's not that hard to make it work. Here is one way:

I patterned the first two rows, did Offset Face, patterned as Surface type, mirrored faces of the first row to get the end.