Sheet metal bend fails

[davecorsello]

Attached is an F360 design in which 3 of 4 identical bends succeed, and the fourth one fails.due to bend interference or uneven thickness.  The thickness of the flange is consistent and is controlled by sheet metal rules.  This is demonstrated in the attached screencast.

[karina.harper]

Hi @davecorsello 

This file is behaving quite strangely.. Was the sketch originally created in Fusion? Were parts of it imported as a dxf or svg or anything like that? I think there are some issues with sketch lines not being straight/slightly off.

Thanks,

Karina

[karina.harper · Accepted solution]

@davecorsello 

When I go through and fix the sketch to make it all horizontal/vertical and make sure all the dimensions are correct, the bend succeeds. Here's the file with the repaired sketch.

Cheers,

Karina

[davecorsello]

Interesting.  The first object in the first sketch is a center rectangle, from which all other sketch objects proceed.  I thought all other objects were lined up with it.  I initially found only one line that would accept a vertical/horizontal constraint.  All other attempts resulted in over-constraint or in the app clocking and then failing to compute.  The only way I could get the bend in question to work was to first remove all mirroring of objects in the main sketch, which allowed me to apply the desired constraints to every line but those in the original center rectangle.  Attached is a video showing me trying to add constraints with the mirroring in place.

This is probably off topic, but my concept of how altering an original object in a mirrored pair should work is that constraints added to the original should simply be reflected in the mirror.  But that doesn't seem to be the way it works.  In my experience, if a sketch reaches some unknown, relatively low (in my estimation) limit of complexity due to symmetrical constraints and/or parameters, I get long freezes and failed computations.  I'm probably underestimating the demands I'm putting on the software.  Maybe my system isn't up to the challenge?

[karina.harper]

Hi @davecorsello 

I started by removing the mirror constraint as well, but I also found that if I remove the top half and start by repairing the bottom half, there are some areas that are a bit wonky. I think there are some over constraints - one way I like to tell if my sketch is constrained in the way I want is to randomly drag it around and see where it goes. For instance, below I constrained the center to the origin to keep it locked, but if I drag the bottom around it reveals where the issues are.

I'm able to apply the horizontal/vertical on these.

Mirroring those features works pretty well.

As to your question about lag times, I find selecting objects one by one to mirror works well, if you drag and select, you get the points as well and it can take a bit longer to compute. @jeff_strater might have some insight on this!

Cheers,

Karina

[davecorsello]

Thanks, Karina.  It makes sense to clean things up before mirroring.  I try to be careful, but I haven't been careful enough.