Not knowing what equipment you have available, it could get expensive just building the framework. The rollers should be machined true and polished.

I agree making your own equipment is a great turn on. If you have the abilities and can scrounge pretty good, it is a doable project.

Good Luck

Rick Sidebottom
Metal Artist
www.spider-webdesign.net
www.ironsidewelding.com

Hey Curtis,
I made one a few years ago, but it's 36" wide. It'd probably do 1/8, but it'd be hard work. I bought an old mangle for next to nothing and used the gears,and frame of that to start with: the rolls are heavy walled tube about 4 1/2" O/D I think. Not perfectly round, but they do most of what I need o.k. Smaller rolls would've left less of a flat at the end of material, and allowed a smaller ring to be rolled, but the gears you use kind of determine the size of your rolls.
I'll see if I can work out how to post a photo or two - failing that if you email me, I can reply with attached photos. Think I may have some plans also I got off ebay. Will have a look!
Will Jones, www.ironwill.org.uk

If you have a really good machine shop, it should be quite possible.
I have a set of storebought rolls that will do 1/8" x 4 feet.
At that size, a motor is essential- you cant crank 1/8" , its just too much torque.
Mine has about a 2hp 3phase motor. It has an electric brake on it, which is really nice, as it stops on a dime. The motor drives the rolls thru a chain drive- similar in scale to a timing chain on a car. This is in turn hooked up to gears on the three rolls, with bearings on each end of the roll as well.
For 1/8" material in 4 foot width, you want rolls about 3 1/2" to 4" in diameter, and they should be solid round. Pipe might work on thin sheet metal, but the forces increase with the square of thickness- so if you double the thickness of metal you are bending, from 16 ga to 1/8", you quadruple the forces on each part of the machine, so they need to be 4 times as hefty.
To turn these, you need a good sized lathe- a minimum of 60", and 10hp or so, I would assume.

Toughest parts to engineer yourself would be the adjustment for thickness of material, with some sort of worm gear arrangement to raise and lower the lower roll, and another one to raise and lower the back roll, to control the degree of bend. This needs to raise both ends at once, the same amount. And, of course, your gear train has to be able to accomodate both of these adjustments.

My commercial one weighs in at about 1300lbs- this is about the mass you need to be able to roll 1/8" without the machine crumpling up.
New, an imported set of rolls like these- mine are Turkish, from Cole Tuve-
http://www.coletuve.com/
is gonna run you around $5000 to $7000.
So yeah, you could save money if you built your own, assuming you have a big mill and lathe, welding equipment, and the ability to troubleshoot and build the gearing and electricals. My guess is, though, that new, materials alone for US stuff, if you bought steel, gears, motor and controls, is gonna be $3K to $5K.
A motor with an electric brake, for example, in 2hp, is gonna run you $800 or so, and usually is only available 3 phase- the single phase models usually stop at 1hp.

I think often people look at a 22 gage sheet metal roll from Tennsmith, that costs $700, and assume they could run 1/8" thru it, and that its overpriced- but in reality, building tools to handle heavier gages of steel gets pricy fast. It takes power, weight, and mass to get a job like this done- I sure wouldnt wanna try rolling 1/8" x 48" material with a mangle...