Unable to update or change sheet metal rules of derived part

[jordan783ZS]

I have been working on a sheet metal part which is a derivation of another paired part. We decided that we needed to design the part in 3mm steel instead of 4mm and so we changed the rule in the original part. Unfortunately, the derived part will not pick up the rule change but picks up all other changes. This causes all of the flanges and other sheet metal operations on the derived part to break.

Because you can't seem to manually change the sheet metal rule for a derived part there's also no way to manually fix this issue.
Is this a bug or is there any known way to fix this?

This same (or at least a very similar) issue was reported by another user a couple of years ago but their self reported fix doesn't actually seem to fix the problem https://forums.autodesk.com/t5/fusion-360-support/change-sheet-metal-rule-in-derived-part/td-p/95380...

[jhackney1972]

You are missing the selection of "Parameter" during the Derive process.  The video will show this.

[jordan783ZS]

Hi John, thanks for that info. Unfortunately ticking that box doesn't fix this issue and the derived part is still stuck on the original sheet metal rule 😞
The dimensions of the derived part in the new model (thickness) are correct, but the listed rules are incorrect and all of the flanges and other features are still broken and seem to be trying to use the old rule.

[jordan783ZS]

The actual error on the flange commands is "Error: EdgeFlange1
Compute Failed - Can't complete Sheet Metal operation due to an internal error. Check the body and bend parameters, then try again."

[jhackney1972]

Please attach the original model if you can.  I would like to test this.  As you can see, it works with my model and the assembly with it derived into so the process is sound.  If you do not know how to attach your Fusion 360 model follow these easy steps. Open the model in Fusion 360, select the File menu, then Export and save as a F3D or F3Z file to your hard drive. Then use the Attachments section, of a forum post, to attach it.

[jordan783ZS]

Hmm I've just tried it again in a new assembly and it seems to work. So going back and selecting those parameter check boxes on the derive feature after the fact, unfortunately, seems to not work, you have to have done it from the start.
Alternatively the second time I used "Insert" derive, whereas the first time I used "Create" derive, no idea if that would make any difference.

[jhackney1972]

You are not holding your mouth right! 🤣  You model works like a charm using the method I outlined in my first video.  I will not return your model as it is a derived model and not worth the effort to deal with.

[jordan783ZS]

I might just have to start it again using the "Insert derived" and have those boxes checked from the very beginning.
I suspect that not checking the parameter boxes originally and editing the derive feature later to check them for some reason doesn't work fully with the sheet metal rules.

Thanks for your help.

[jhackney1972]

I just did it the using the other method, instead of Deriving the model in, I used the Create Drive method and all worked the same.

Edit: Just as a note.  I do not have the Parameter check box on all the time, only when I Derive and need it.  Do not forget to Accept Solution if your question is answered.

[jordan783ZS]

So doing some experimenting it seems to be having "component" selected instead of "object" which causes the issue to occur. When object is selected everything seems to work fine.
If I derive the sheet metal compoenent as a component (not an object), without parameters selected, and then later try to enable those parameters, and then change the rule of the original part, any flange commands applied to the derived part fail.

Edit: Actually I seem to get the error with the derived component regardless of if the boxes are checked or not.

[tyler_henderson]

I have verified the issue you described.  There is indeed unexpectedly different behavior when you use the "Derive Objects" option versus the "Derive Component" option.  I've filed a defect, ref FUS-118474.

Thanks for reporting this.

[jordan783ZS]

Glad to know I'm not going crazy haha.
Thanks for filing the report.