e-wheel, beadroller???

[Dan]

the kids in shop are making an aircraft style seat and I have a couple of questions...rolled it through our e-wheel to form the radius and it is getting a bunch of ridges in it??? It is shaping it pretty good but the finish looks real ugly??? When rolling the beads in we are getting some oilcanning?? Tightening down the rollers too much??? We are using a piece of very thin (I think it is 26 gauge??) piece of stuff I bought at the hardware store, I thought it was aluminum but it looks galvanized, is that a possibility?? I though it would probably be too thin to use (but good for practice)but the more we put beads and such in it I think we may be able to stiffen it up quite well - any advice is greatly appreciated!

[chopolds]

1. The metal is WAY too thin.
2. if you are getting ridges, your wheel pressure is too high.
3. Beads are drawn up, not stretched into the metal. You will get a bit of distortion. Make the beads as shallow as possible, & maybe stretch the area outside the bead to relieve the stress put into it.

[Unkl Ian]

Your wheel pressure is too high,an/or
your using a lower wheel with too much crown for the shape you are making,and/or
the shape of the lower wheel has a transition from the radius to the flat that is too sharp.

Bead rolling doesn't stretch the material the way some might think.
It actually draws material in from the sides.
So the panel want to be narrower where the beads are,and wider at the ends,
which creates additional stresses causing distortion.
You should be able to measure this effect on a very narrow panel.

Some guys will pre-planish the middle of the panel,where the beads will go,
to create a little extra material for the roller to draw in.
It would take some practice to know exactly how much you would need.

[Slag Kustom]

i go back and shrink the panel at the ends of the beeds to flatten it back out

[Dan]

I agree that the metal is appearing to be WAY too thin...I think it is working as a good teaching tool though as it is pretty easy to form and pretty easy to see what effect different processes have on the metal. I think I may try to make some swedged holes holes to see what effect they have on strengthing the metal. I thought I would take a dowel and round over one end, then drill a hole the same size as the dowel (probably just a hair bigger??) in a board. Drill a hole in the metal, sandwich it between the board and the dowel and hammer the dowel down into the hole thus creating a swedged hole???