Steven Barry

Edge Flange command wants me to use "Bend Outside"... I don't want to!

Discussion created by Steven Barry on Mar 4, 2016
Latest reply on Mar 8, 2016 by Bernie Daraz

So let me start by saying I really dislike when sheet metal parts are created with edge flanges using the "bend outside" option.  I think it's bad practice, because if someone uses different K factor / gauge table / bend allowance, etc. information, your part will not have the same overall dimensions (radius can vary based on the forming die!)

 

At my job we do a lot of contract work involving sheet metal, so we will often receive SolidWorks parts from customers which are created using this method.  I have to take these parts and change the gauge table information to match what we use to fabricate them.  If I do this step right away, the overall part geometry will change (they often assume a different bend radius than us).

 

What I do instead is attempt to "correct" their part, by changing all edge flanges to a "Material Inside" condition, and then adding an offset equal to their assumed bend radius plus the material thickness.  This way, when the radius changes, the flange positions will not change.  The problem I have is that when I do this, SolidWorks gives the error:

 

"Offseting the flange failed with the selected flange position option.  Please use the 'Bend Outside' option"

 

I'm sure there is a perfectly good programmatic reason for the developers to choose to do this, but it is an inconvenience, and I refuse to use "bend outside" in general for sheet metal design.

Some workarounds I'm aware of, and why I don't prefer having to use them:

 

- Add material or change the geometry of the base flange so that the offset is not required

     This is what I normally end up doing, and what makes the most sense, but sometimes it creates a bit of extra work depending on the part geometry

- Add a tiny fraction of an inch to the offset so there is no conflict

     I hate doing this, it makes me cringe.  Even though I know it's insignificant, I like my dimensions to be exact

 

Anyone else have any experience with this?  Do you hate "bend outside" as much as I do?

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