topic Can't bend sheet metal: Curve broken into two discontinuous pieces in Fusion Design, Validate & Document Forum

Can't bend sheet metal: Curve broken into two discontinuous pieces

rossjm5075 — Wed, 06 Apr 2022 05:30:49 GMT

I'm trying to bend the attached model along the horizontal dashed line (by 16.1 degrees), (using "Center") but I keep getting the error "curve broken into two discontinuous pieces," and I'm unable to complete the bend. Does anyone know how I can fix the model to avoid that error?

I would have included a Screencast as well, but I upgraded Screencast today, and now my Screencast is not working at all!

Many thanks in advance!

Re: Can't bend sheet metal: Curve broken into two discontinuous pieces

laughingcreek — Wed, 06 Apr 2022 07:32:36 GMT

i just bent the 2 tabs up separately instead of in 1 selection.. not sure why this worked.

Re: Can't bend sheet metal: Curve broken into two discontinuous pieces

hamid.sh. — Wed, 06 Apr 2022 07:39:54 GMT

First point: the sketch is problematic; lost plane, has duplicate lines, not coincident points, underdefined, etc. Just by cleaning up the sketch without changing its profile at all I could bend it to 10 degrees:

Second: the bend lines in this area are too close for your bend radius, by increasing it to 1.3 mm I could bend 16.1 degrees without a problem:

Re: Can't bend sheet metal: Curve broken into two discontinuous pieces

TheCADWhisperer — Wed, 06 Apr 2022 14:39:29 GMT

@rossjm5075 wrote:
I would have included a Screencast as well, but I upgraded Screencast today, and now my Screencast is not working at all!

What OS (Mac or Windows)?

Have you reported the issue here >>https://forums.autodesk.com/t5/screencast-forum/bd-p/58<<?

Re: Can't bend sheet metal: Curve broken into two discontinuous pieces

rossjm5075 — Wed, 06 Apr 2022 14:46:58 GMT

Thank you! Three questions: 1. What does "lost plane" mean? 2. I spent hours looking for non-coincident points (by massively zooming in, and also trying to hover to see if there was a coincident constraint). Evidently, I missed some. Is there a better way more quickly to identify non-coincident points? 2. Ditto for duplicate lines. I tried scanning all the lines, and eliminated several duplicates, but evidently I missed some. Is there a good way to more quickly/accurately identify these? Thank you!

Re: Can't bend sheet metal: Curve broken into two discontinuous pieces

TheCADWhisperer — Wed, 06 Apr 2022 15:02:34 GMT

@rossjm5075 wrote:
Thank you! Three questions: 1. What does "lost plane" mean?

This highlighted face is gone - it appears that you Deleted parent geometry.

@rossjm5075 wrote:
2. I spent hours looking for non-coincident points (by massively zooming in, and also trying to hover to see if there was a coincident constraint).

No need to zoom in - the missing Coincident Constraints are indicated by the white dots at line endpoints...

I recommend that you model in Finished Folded form rather than attempting to fold from flat.

You are otherwise likely to encounter Bend Allowance issues.

Re: Can't bend sheet metal: Curve broken into two discontinuous pieces

rossjm5075 — Wed, 06 Apr 2022 16:35:32 GMT

Many thanks, @hamid.sh. and @TheCADWhisperer for your extremely helpful tips/solutions. For practice, I tried to clean up my original model and then re-bend. I believe I replaced the lost plane, got rid of the non-coincident points (no white points any more), eliminated duplicate lines, and constrained everything. But I still can't bend it. I get the error: "attempt to fit curve to zero knot span," even when I try to bend by just 1 degree. Many thanks in advance if you can see what I'm doing wrong. Once I master this, I'll take @TheCADWhisperer 's suggestion and try modeling folded shapes in the future, but I want to make sure I understand all this first. Thank you!

Re: Can't bend sheet metal: Curve broken into two discontinuous pieces

laughingcreek — Wed, 06 Apr 2022 16:55:27 GMT

screen cast of model I posted in pervious answer. You have to bend the 90 tabs in separate actions.

Re: Can't bend sheet metal: Curve broken into two discontinuous pieces

rossjm5075 — Wed, 06 Apr 2022 22:58:08 GMT

@laughingcreekThat's super helpful, many thanks! One last question (I think!) on this topic . . . In the "Bend" dialog, when I check "Bend Relief Override" and "2 Bend Corner Override" and enter various numbers to see how these affect the model, the outcome doesn't change versus the outcome when those are not checked. In other words, those selections don't seem to have any affect on the final folded model. Any ideas about why these are seemingly not working?