Roll Forming - Straight between bends
Roll Forming - Straight between bends
(OP)
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
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





RE: Roll Forming - Straight between bends
The straight between bends will depend on your roller profile and the number of rollers you have on the machine.
I am presuming that we are discussing a Yoder or lockformer multiroll former here.
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
RE: Roll Forming - Straight between bends
remember too, it's very hard to create a bend across the curvature of a panel ... ie if you roll a sheet into a curved shape (like part of a cyclinder), it easy to bend a flange along the axis of the cyclinder, but it's very hard to form across teh cyclinder.
also, if you're forming a complex shape, it's probably better to do it in O condition material and heat treat later.
RE: Roll Forming - Straight between bends
Thanks,
Jeff
RE: Roll Forming - Straight between bends
RE: Roll Forming - Straight between bends
For that profile rb1957 has it right. You can go back to back with your bends.
What I was talking about, was how short you could make what are your vertical legs on that part.
The radius of the bend of course will depend on the ductility of the part.
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
RE: Roll Forming - Straight between bends
In my opinion it's to complicated for roll forming.
then the amount of straight between bends is not applicable.
an other option is to brake form.
generally the length of bend requires enough for the machine to grab at the ends.
simple for hydro forming, then maybe brake form, discuss it with your shop or vendor.
Mfgenggear
RE: Roll Forming - Straight between bends
Jeff
RE: Roll Forming - Straight between bends
It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.
RE: Roll Forming - Straight between bends
Jeff
RE: Roll Forming - Straight between bends
It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.
RE: Roll Forming - Straight between bends
depends on the quantity. regardless of material.
are we talking about pinch roll forming or extruded roll forming.
if it's extruded, I would agree if the quantity would pay for the tooling.
jmararkus
are you making only 1 or 2?
I would still stick with my first answer.
Hydro form if it's low- to mid production.
for what ever reason I was thinking pinch roll forming.
Mfgenggear.
RE: Roll Forming - Straight between bends
Are you roll forming this yourself, or are you sending this out.
For an experienced roll forming company with a good multi roll forming machine, this job is a no brainer.
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
RE: Roll Forming - Straight between bends
RE: Roll Forming - Straight between bends
RE: Roll Forming - Straight between bends
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Roll Forming - Straight between bends
The type of roller he needs looks like this.
B.E.
http:
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
RE: Roll Forming - Straight between bends
yes you are right for long runs.
htt
RE: Roll Forming - Straight between bends
http://www.youtube.com/watch?v=2-1wbvuqEuA
RE: Roll Forming - Straight between bends
Damm that brings back memories, I played with one of those with an ETS2000 controller for about 3 years starting in 2001.
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
RE: Roll Forming - Straight between bends
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
RE: Roll Forming - Straight between bends
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