Tabs in sheet metal

Mark_Bantle

I am trying to do a project with my students where they design packages for products. I have used the sheet metal tool and seen about adding tabs, but we keep running into an issue. If I create a cube (for example) and create the sheet metal feature to enclose it, with bends, we can see the flat view of the package. When I try to add tabs to the sides that meet, (in order to glue the sides together) I can only put two tabs on a side. Adding a third tab to the side that is the last to close on a simple box gives me (and my students) and error.

Is there a secret to this? Or a better way?
I want my home bound students to create models at home, where all they have access to is paper. 
Thanks for the help,
Mark

john_mcclary

It probably has something to do with being too close to the bends I would guess. That's usually the problem with sheetmetal parts.

Hard to say without seeing what you are doing 

bryan_lagrange

This is the closest I could come to folding paper:

https://cad.onshape.com/documents/e567435b5c310971ffed3d37/w/ede3ec84fc869dc0f9215ee4/e/d8cac2c84f7957a1e104bfc7

matthew_stacy

@bryan_lagrange, I like the Move Face trick.  Well played!

@Mark_Bantle, I think the inherent challenge is that a CAD sheet metal model is governed by strict mathematical rules.  Whereas a cardboard box or other packaging can easily flex around the discrepancies. 

When a tab tries to occupy the same spacial volume as another portion of the same part model any decent CAD software (Onshape included) will cry foul.  Bryan's solution is probably about as good as it gets.

$0.02-from-the-desert