Cannot refold sheetmetal object

[matthewrjacobs]

I'm using sheetmetal to assist in the scroll for a  violin neck,  when I try to refold it I'm getting an error message.  I don't have the actual error right now because I'm at work, however its something like "the bend is over constrained".

I have used this workflow successfully before,  and I did get a similar error, but was able to find a workaround.  I don't recall exactly what the workaround was,  but I think it was to create the stationary face in the solid environment and do a Combine/Join.  but that isn't working in this case.   I have also tried extruding the stationary face in sheetmetal,  but that doesn't fix the problem.

When I unfold up to the point indicated in red the in the screenshot below, I am able to refold, but when I go past that it fails.  I have looked at the geometry in the sketch at the point where it breaksdown,  and it looks the same as the other areas, so I don't know what's going on. 

Sorry I couldn't get a screenshot from fusion,  so I had to grab it from the remote viewer.  

File is pasted below

Thanks!

[TheCADWhisperer]

For "sheet metal" Unfold/Refold I would avoid using Splines and instead use only tangent arcs/lines as need to reproduce the curve well within any realistic manufacturing tolerance.

[matthewrjacobs]

@TheCADWhisperer ,  thanks for the input on the splines.   The reason I'm using splines is to minimize the surface edges created during the flange operation.   In previous versions of this,  these edges caused some downstream problems.

I'll try replacing the splines with tangent arcs,  and see if that makes fusion happy. but,  the problem area seems to be in the part of the scroll where I am using tangent arcs.   

[TheCADWhisperer]

In that case - take out the spline and narrow the issue down step-by-step to the tangent arcs.

I haven't tried this - but the edge of a Surface Body Spiral might be the best technique for that area.

[matthewrjacobs]

@TheCADWhisperer,  I replaced the splines with tangent arcs and it didn't change anything.  The refold still fails once I get to the arc indicated in my initial post.  I did try replacing that arc with a spline and was able to fold all the way up to the last arc (the eye of the scroll),   but when I get there the refold fails.  I tried replacing the last arc with a spline, but the refold fails.

@jeff_strater,  do mind having a look and/or elevating to the sheetmetal  team,  the behavior of refold (in this case) seems to be erratic.   I can unfold/refold the first bend or two at will, but it will fail if I try to refold beyond that.  However, if get a successful refold, then I can go back in the timeline and edit the unfold, and get the refold to work as indicated above. It's like if fusion knows the body can be refolded, it will allow more bends to be refolded.  (hope that makes sense)

I have used this workflow before with almost identical sketches,  so I know it works,  just not working here.

[jeff_strater]

I created issue FUS-92523 to track this.  I agree - if you can unfold it, you should be able to re-fold it, splines or not.