topic Strange extrusion behavior. Objects/faces missing on compute. in Fusion Support Forum

Strange extrusion behavior. Objects/faces missing on compute.

jeffsimovich — Fri, 07 Aug 2020 02:01:01 GMT

I created what I would consider to be a fairly basic sketch. Its really just a very simple plate with several holes in it (see below). During extrusion the sections I want are selectable, and show as such. But once completed a section of my new body is non-existent.

My first solution was to add the line intersecting the lower pair of circles. But the problem persisted. That lower area does have a projection from another sketch in it. In order to easily establish a center point (its very hard to see as its 0.25mm smaller than the the circle of the correct size).

Not sure if this is a bug or incompetence on my part. Never had an extrusion fail like this. Without throwing an error/warning as to why.

Any help/insight would be greatly appreciated. Thank you!

Re: Strange extrusion behavior. Objects/faces missing on compute.

davebYYPCU — Fri, 07 Aug 2020 02:23:46 GMT

Can see the problem, but can't help without the file.

Check for duplicated sketch articles overlaying themselves.

Re: Strange extrusion behavior. Objects/faces missing on compute.

jeffsimovich — Fri, 07 Aug 2020 02:45:43 GMT

Thanks, I think you where probably right. I was thinking it could of been something like that. But wasn't sure, as fusions is generally quite vocal and helpful when things fail to show.

I deleted the projection, which did nothing. Then just deleted the pair of likes on the right and left side. Going from the centerline of the circles to close the sketch. Then redrew them. Then it worked.

Didn't want to potentially sit on a bug and not say anything if that was the case.

Re: Strange extrusion behavior. Objects/faces missing on compute.

jeff_strater — Fri, 07 Aug 2020 14:58:32 GMT

@jeffsimovich - saw this last night, but was too tired to do anything with it. Yes, this is a bug - we have seen a few cases of this in other models - almost always with tangencies, that seems to confuse the profile matching algorithm. If you could share the model here, or privately to me via link in a direct message, I can add this to the list of bugs in this area, to make sure that this case is part of that project. Thanks!

Re: Strange extrusion behavior. Objects/faces missing on compute.

jeffsimovich — Fri, 07 Aug 2020 16:20:15 GMT

@jeff_strater I am glad I made an effort to save it at a point that could help.

Main component - Bugged sketch is named "sketch in question" and is the last two events on the timeline.

https://a360.co/2C5nAIG

Re: Strange extrusion behavior. Objects/faces missing on compute.

TheCADWhisperer — Fri, 07 Aug 2020 16:59:46 GMT

@jeffsimovich wrote:
I created what I would consider to be a fairly basic sketch.

Poor sketching - user error.

Note the three points on left side are not coincident.

Notice that the three points on right side ARE coincident.

Missing Tangent at upper right vertical line.

Missing Horizontal constraint on Horizontal line in center of lower circles.

Missing Midpoint to same Horizontal line. (And I would change the line to Construction.)

Missing Symmetry.

Missing Dimensions.

Note that the original image that YOU posted clearly shows user error.

Re: Strange extrusion behavior. Objects/faces missing on compute.

jeff_strater — Fri, 07 Aug 2020 16:59:11 GMT

thanks, @jeffsimovich - I created Fusion bug FUS-70419 for this issue. Thanks for reporting it and sharing the model.