Flat pattern not showing in drawing view - sheet metal derived from solid

[Anonymous]

Inventor Professional 2018.2.3 64 bit on Windows 10

I will sometimes create a sheet metal part from a derived solid to simplify the development of a weldment containing many interrelated sheet metal parts (derived from the same solid.)

I have run into a problem whereby the sheet metal flat pattern will not show in a flat pattern drawing view.  This happens when I derive a sheet metal part from a solid then delete one of the faces of the derived solid to turn it into a surface. I know I can derive a surface directly but deriving to a solid allows me to modify the solid easily then turn it into a surface by deleting a face. I can then create my sheet metal part on the remaining faces.

The sheet metal part is created easily on this new surface body and the flat pattern works out well; however, when I try to add this flat pattern to a drawing view, the view shows nothing.

This problem is not consistent. Some parts I create this way work out well and some do not. It only seems to affect the drawing view. The type of derived solid does not seem to matter - whether a single body with or without seams or as separate solid bodies. I suspect this has something to do with the Inventor software seeing the surface body as a solid body and therefore as a multibody part, which is not allowed in flat pattern drawing views.

Please see the attached parts and drawing. The drawing view of Part2 is in the center of the drawing.

[Xun.Zhang]

Hello @barsea,

Thanks for reporting back. It is a problem for 2018.3 and reproducible in my end as well.

However, it was fixed already in Inventor 2019. Could you try it and recreate the drawing file?

https://autode.sk/2S0yty3

Thanks!

[johnsonshiue · Accepted solution]

Hi! On 2018, you can open the part and do Rebuild All. The flat pattern view should be shown correctly.

Many thanks!

[Xun.Zhang]

Hello @Anonymous,

Johnson and I worked together for a while with this particular problem in 2018 version, unfortunately, there is still some trouble to solve it in 2018. 

Hope it helps!

[Anonymous]

I tried Rebuild All in 2018 but it did not work for me; however, when I opened the model in 2019 initially the behaviour is the same until I Rebuild All, then the flat pattern appears in the drawing view. We have not yet migrated to 2019 as a company (although we have a subscription for it) so this is the first I've been able to try it.

[Anonymous · Accepted solution]

I have recently found a quicker fix for this problem. You just need to use the delete face tool with the heal box unchecked to remove a single face from the derived solid. This will convert the solid into a surface body and you can make a flat pattern. There may be some errors this way but it is quick and easy. Otherwise turning the part into a component separates the part from the derived solid and you can do what you want with it.