mark
Well-Known Member
Yes, a Brake press is the proper tool. I doubt a sheet metal shop with have any die with that big of a radius, but you never know.
The are all sorts of calculations to figure it all out, but like was mentioned, you can make a low-production set pretty easy. Find a pipe or tube (heavy wall or even solid) with the right OD to match the inside radius of the part your after. Then find, build or machine a bottom die with a 3/16" bigger radius.
You can get fancy any make it all up with guild rails and the such, but for very low production, or proof of concept, mount the top die in your hydraulic shop press, center the bottom die as best as you and clamp it down, then make some test strips to try it out, and figure out were top put some material stops to get the correct "tail" on the wrap around.
Jack it down, bottom out the dies and max out the press and check the fit. Should be pretty close. Any spring back could probably be fixed by hand if its only 4" wide.
Full height (width) would need a much bigger press than most peoples shop press. Best left to a pro. shop.
If you don't want to make a die set, and you can't find a shop with the right radius it *can* be made with multiple smaller bends. The more the smoother the radius (after all a arc is made up of infinite strait lines ). Will probably give you a ribed look, which might be cool, or look like ass.
The are all sorts of calculations to figure it all out, but like was mentioned, you can make a low-production set pretty easy. Find a pipe or tube (heavy wall or even solid) with the right OD to match the inside radius of the part your after. Then find, build or machine a bottom die with a 3/16" bigger radius.
You can get fancy any make it all up with guild rails and the such, but for very low production, or proof of concept, mount the top die in your hydraulic shop press, center the bottom die as best as you and clamp it down, then make some test strips to try it out, and figure out were top put some material stops to get the correct "tail" on the wrap around.
Jack it down, bottom out the dies and max out the press and check the fit. Should be pretty close. Any spring back could probably be fixed by hand if its only 4" wide.
Full height (width) would need a much bigger press than most peoples shop press. Best left to a pro. shop.
If you don't want to make a die set, and you can't find a shop with the right radius it *can* be made with multiple smaller bends. The more the smoother the radius (after all a arc is made up of infinite strait lines ). Will probably give you a ribed look, which might be cool, or look like ass.