Roll Forming - Straight between bends 1

[jmarkus]

I couldn't find a specific area to ask about roll forming, so I hope this forum has some expertise. I've read a lot that for a straight flange after a bend in roll forming the length should be at least 3 times the material thickness.

What I am wondering is what is the requirement for straight length between bends? If I have a complicated section profile with jogs here, there and everywhere, what is the best practice design requirement for how much space I need to keep between the bends.

Thanks,
Jeff

 

[jmarkus]

I appreciate all the excitement about the part I have shown. However it is simply a demonstration model I whipped up in order to clarify my question, it is not a real part.

I am trying to gather information about designing for roll forming and looking for simple "rules of thumb" where available.

I believe the consensus seems to be there is no rule of thumb here and it isn't a limiting factor.

Thanks for the enthusiasm,
Jeff

 

[berkshire]

jmarkus (Mechanical)
The limiting factors are most often in the metal you are trying to form.
With roll forming you can: fold, flatten, stretch,pierce, and crimp.
The limiting factors are selection of rolls from stock or creation of special purpose rolls.
For short runs it is often simpler to creat parts in a leaf brake or press brake. Then go to roll forming, if you have enough quantity to justify the setup.
B.E.

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor