unfolding sheetmetal

We are messing around with unfolding sheet metal parts. One problem we are encountering is that the unfolded parts are not workable. The stretch that happen during bending is different from what wildfire calculates. we have used different bend allowance table and k facters ... but still the bend allowance/ stretch are off. Usually when we calculate stretch at the shop for stainless steel we use 1.6 X thickness and that give us a very accurate stretch. Where can we find info on how to get wildfire 2 to unfold with the correct stretch/bend allowance?

Reply to
bigmouth
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stretch that

I've had the same problem and have had to resort to assigning each wall to look at a specified bend table. Even then, I've had to go back and double check each developed length to make sure. Generally a few still aren't right and reassigning the DL to "return to driven" will get it right. Personally I think that PTC has really screwed up the Sheet Metal module.

Marty

Reply to
hangdog109

There's still no ability to pattern a Flat Wall, Flange Wall and certain other types of Wall features. I would like to have the ability to perform an Unbend Sel on an Unattached Wall feature that is in its formed state when there are other Unattached Wall features present in the model. Of all the Pro/ENGINEER modules that we use regularly, Pro/SHEETMETAL needs the most improvement for the types of parts that we design and manufacture.

J. Perry

Reply to
J. Perry

To clarify the Unbend Sel request, I am referring to models that contain multiple Unattached Wall features that are not yet connected with Merge Wall features.

J. Perry

Reply to
J. Perry

Not sure why they don't allow a user assigned value that isn't related or effected by a radius or mtl thickness change. In other words, select a wall/bend and assign a bend deduction value for it that isn't associated with a bend table - I believe SW has this capability

Reply to
CKERIDES

The easiest way to get the correct flat layout is to calculate what the actual inside bend radius will be in fabrication and then create the model using the actual inside bend radius. As long as the neutral axis in the sheet metal setup is .44 (44% of material thickness) then the flat will be correct. It is easy to calculate the actual inside bend radius as long as the type of forming, material thickness, material type, die width, and punch radius are known. You can also calculate the tonnage required, which can be very important, especially if you have limited bending capabilities. If the equipment doesn't have enough tonnage to form a particular part then a larger v-die can be used to reduce the tonnage required, but a larger die width will also increase the inside bend radius, which will result in a larger bend deduction, which will ultimately reduce the size of the flat blank. I never use bend tables and I have done many process capability studies to verify my calculations, and there are very accurate. There is also another factor that will effect the inside bend radius on aluminum and it is the grain direction. I did studies and found a happy medium which works well...

Bye

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Reply to
Brooke

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