FS for sheet metal slotted bend lines?

John_vd_Werff

I was looking for some examples of designs for precise sheet metal bend lines and found a patent with a series of interesting slotted bend line designs.
According to Google the patent is expired since 17-8-2020 and the designs can be used free.

It looks like something that could be an useful FS. 
I just started using Onshape and don't yet have the required experience (or the time) to write a FS myself, but maybe somebody on this forum with the coding expertise and an interest in sheet metal would like to take a look at it?

Patent US7152449 
     

  

michael_unger759

Hey ... nice ideas!!!

Any News about this? - or have you found something else?

Thanks,
Michael

NikNYC

When I implemented this in Rhino/Grasshopper there was no hope to emulate full 3D twisting that is not even normal sheet metal bending at all, but making it all work in the 2D flat pattern was relatively trivial, so then you just get the 3D model in real life as a test cut piece. Here are 16GA thick samples.

The Grasshopper script simply inputs manually drawn flat pattern lines where I want the bends to be then adds offset dotted lines with fancy (or no) curly ends.

There is typically zero "bend reduction" since the twisting pulls the edges perfectly together, so the sheet metal flat pattern starts very simple.

Here I manually create the straight blue lines and am offered the cyan curves also as simple lines. They are then waterjet cut (kerf 0.04") and bent with a pliers.

So an Onshape FeatureScript would merely need to do good bookkeeping to create slightly offset dotted lines on either side of each sketch line and cut them in half at the ends/corners.

Using no extra curly ends is often best if the resulting bends are to be welded and finished, to avoid pinholes.