If you are making a full size model it can be made of cardboard if you
like..
If the operator has sweeps for each radiused section it is easier. A
sweep is simply a crescent shaped template about a foot long that can be put
up against the plate as the operator is bending it. A sweep for each edge
of the curve would be needed,
If the forming is perfect then you will not need a porta-power.
Actually for 1/4 and 3/8 plate a couple of chain com-a-longs, dogs and lots
of steel wedges will do the trick.
The welding to connect sections will have to be done carefully or else
the weld seam will increase or decrease the curvature giving a kink in your
nice curve.
Making a quarter size or smaller scale unit out of 1/8th plate might be
economical.
Randy

"Richard Ferguson" wrote in message
...
What you suggest is more or less how I envisioned making a Mobius out of
1/4 or 3/8 inch plate. I was thinking of makeing a full size model out
of sheet metal, and then using the model as a template to guide the
press brake work on the plate.

Besides the issue of finding a shop willing to try something strange on
a time and materials basis, there are all the learning curve issues. I
might be well advised to build a medium size Mobius out of 1/8 inch
sheet before stepping up to something heavier. Getting it all to fit
together right would also be a challenge. Probably would need a
porta-power or other way to exert major forces to get things aligned
right for welding. And how do I get the joints to have a consistent
curve if I can't use a hammer to make adjustments?

Looks like a challenge. It is something that I have been thinking about
for a while.

Richard


R. Zimmerman wrote:

It is doable with a press brake on quarter inch or even heavier. Of
course
you would not be able to make the complete strip in one piece. I would
guess the revolution might take four pieces, maybe three depending on
radius, width of strip and clearance on the press brake.
To create the layout you will have to do a series of triangles to get
the development. Look up in a sheet metal layout or good drafting text.
Some developments are parallel line, radial lines and the last method is
triangles
Once cut the forming will be a series of hits not parallel to each
other. The tighter bend area will have hit lines closer to each other
compared to the large radius areas. It is not unlike forming spiral
shapes.
Randy


"Richard Ferguson" wrote in
message
...
I know that one can bend plate in a slip roll or with a press brake.
But how can one put a twist in plate, like taking a strip of plate and
twisting it such that the bottom becomes the top? Is that just a matter
of putting a bend at an odd angle? But how can I get a very different
radius at each end of the bend? With sheet metal, it is pretty easy
with hand tools and jigs.

I confess that I have never even seen a press brake, and have limited
experience with slip rollers.

If you want to know why I want to know, or a picture of the application,
click this link:

http://fergusonsculpture.home.att.net/mobius.html


Richard


--
http://www.fergusonsculpture.com
Sculptures in copper and other metals




--
http://www.fergusonsculpture.com
Sculptures in copper and other metals