roll former? manual type

I work in a product design firm. We fabricate models some of which have steel and aluminum tubing approx .036 wall X 1.5 dia. bent into sweeping
curves: 15" - 40" radii.
I've been looking into roll benders - 3 rollers 2 or 3 powered. You pass the tube between the rollers 1 of which is moved closer to the other 2 to get the large bend radius desired.
There are nice machines out there but they are $3,000.00 - $6,000.00. We only do a few bends a week. Has anyone seen a manual bender? The drive die is turned by hand. I've been told they exist and I saw plans for one on Ebay. Someone said that he recalls seeing an ad in the back of a metal working mag. for one.
Any help - leads would be appreciated.
Thanks for any info. - Rob
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Found a couple: http://www.rutuonline.com/html/tube_bender.html
http://www.metalworking.com/DropBox/_2001_retired_files / start with Roller__0_Explaination.txt and keep looking
designo wrote:

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Rob:
Lots of manual slip rolls still being made, Roper-Whitney, Tennsmith, Di-Acro plus lots of Asian makes too. For example, www.tennsmith.com. You can find the others on the web as well.. You can also find them in the major industrial catalogs like MSC.
George
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The one with the rollers between a pair of plates is very easy to build as you merely need to do 2 holes and 1 slot in each of the plates (do them together on the mill so that they are perfectly straight) and a carrier for the third roller that can be pushed to some particular location. Don't forget to make the rollers to the shape of the material that you are bending as this will keep the material from changing shape. I've used on with a hand crank for a power device that worked very nicely. The single sided bearing style is acceptable but does need to be built sturdier for the same working forces. Don't forget to use good heavy duty roller bearings for the bearings. Anything light will tend to have a short life. -- Why isn't there an Ozone Hole at the NORTH Pole?
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We manufacture a three wheel ring roller that retails for $2650. It has a full one HP motor and is capable of bending 1-1/4" SS sched 40 pipe and I have rolled 1/4" SS into 6" rings with one. We have sold about 25 units now and most SoCal marine rail shops have an example purchased directly from MarMachine. Leigh at MarMachine
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First, a little proper semantics- what you want is not a "roll former"- that is a large and complicated machine for making flat sheet into profiles linearly, like a gutter forming machine. And it is not a "slip roll"- that is a tool for bending flat sheet metal into cylinders.
There are several types of machines that do what you want- there are pipe and tubing benders which use a fixed die to make a repeatable radius, and then there are three roll benders like you describe, which are usually commercially called "angle rolls" or "section rolls", as they were often used to roll angle iron into curves.
Commercially made motorised ones are, indeed 3 grand and up. And worth it, as they actually work. I have a big one, and I love it. Eagle imports some nice ones from Italy. http://www.eaglebendingmachines.com /
There are some hand powered ones available, but they are mostly for flat bar the easy way, as there is a lot more friction involved with bending tube or pipe. And you will need a dedicated set of dies for each size of pipe you bend. Decent dies machined and heat treated from good tool steel can easily cost 3 or 4 hundred bucks each. These guys make rolls sort of l like what you want; http://www.rdhs.com / http://www.shopoutfitters.com / http://www.bossbendersusa.com /
the one shot benders, which the auto and motorcycle guys use, are another way of doing this- best is probably the hossfeld clone made by JD2- http://www.jd2.com /
This is a job where the simple, hand powered tool really isnt the best thing for the job- there is a reason why people buy the big powered ring rollers, and its not just because they like throwing money away. But for occasional use, one like the rdhs model might work. I would send them a sample of your material, and have them roll it for you, before I bought one. That way you can see if it squishes the inside of the curve, or leaves marks- (some machines use serrated rolls to grip the material, so it doesnt slip).
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