Bend lines in flat pattern missing

[AdamAG99T]

I have a sheet metal part that is missing the bend lines in the flat pattern, both in the part file itself and when placed into drawings. The flat pattern will show the bend extent lines however. It only occurs after I refold everything, if I move the end of part above the refold the bend lines work as normal. I tried tweaking some sheet metal rules but nothing seems to fix this.

I am using inventor 2019.4, build 330, on a windows 10 computer. I can work around this easily enough so I'm not desperate for a workaround, simply thought I should bring this bug to Autodesk's attention, or possibly learn of some deeper issues with this fairly simple file that could be causing this.

[KKizildemir · Accepted solution]

Hi @AdamAG99T 

There are problems on the bends of your sheet metal part. If there is a flange extension on your bend radius, Inventor hides bend line. This is a basic warning to prevent this kind of design issues.

When I change your part from this:your part's bends

To that one,

updated bends

the problem has gone!

result

Please find your updated part attached.

Regards,

[AdamAG99T]

Interesting, I did some testing and this seems to be a somewhat inconsistent behavior. I made a quick sample part and it seems that it depends on if the cut extends past the edge of the metal or stop exactly on the edge. In this quick test part cut 1 and cut 2 will produce the same end shape in the sheet metal, but only cut 1 will properly show the bend lines. Cut 1's sketch ends exactly on the edge of the sheet metal while Cut 2's sketch ends a bit past it. Hopefully someone from autodesk can chime in with an explanation for this inconsistency.

Cut 2 activeCut 1 active

[cadadmin]

I agree with the inconsistency description, we have also been experiencing issues with flat patterns as well as sheet metal parts in general. On both newly created parts and legacy parts that did not have issues in previous versions (2018, 2016, etc.). I have one sitting on my table I need to send to support which shows the bend lines exceeding the tab reaching across the entire part. However it is an odd part which does not have many 90° angles. We have been "faking bend lines" in drawings as a band-aid. Not optimal, but we can't wait for fixes and reverting to 2018 is no longer an option.

[johnsonshiue · Accepted solution]

Hi Adam,

This is a bug. It was reported as INVGEN-28757, which is still being investigated. Hopefully, it will be fixed soon.

Many thanks!

[Anonymous]

Hi, has this been resolved? Got the same issue and im using 2020 Inventor.. cheers.

[johnsonshiue]

Hi! The defect was closed as of 2020.2 update and later releases. Please make sure you have install 2020.4 update.

Many thanks!

[Mild_Annoyance]

@johnsonshiue 

This may have been fixed previously but I found this post cause I am currently having this exact issue while running Inventor 2024.3. I have a contour roll in the shape of a channel. If I move end of fold to above the final refold of the part then I get all of the bend lines in the flat pattern however as soon as I move it below the final refold I lose 1 of the bend lines.

[johnsonshiue]

Hi! If possible, please share the file here. Unless the bend is a spline face, the bend line should be there. I would like to understand why the bend line drops in this case.

Many thanks!