When I first started making the Mini-560, I needed a way to make the hood. I had two sophmore students that were looking for a project to work on. I gave them a project of making a bender that would produce a 2″ diameter 90 degree bend. They came up with the bender discussed here. If you’re a little older and grew up on a farm, you may recognize the two outer rows as coming from an Allis Chalmers baler.
I’ve used this roll bender to make the hood for the Mini-560, Mini-H and Artie and I’m currently using it to make a hood for a Mini-Cub I’m working on. It’s not real fast and takes a lot of patience but I’ve been very satisfied with the results.
As mentioned the two outer rollers are from an Allis Chalmers baler. The center bar is a piece of 2″ hot rolled steel. (I also have a 1″ O.D. pipe that I can use to make a smaller bend radius.) The two outer rolls are adjustable in and out to allow for clearance for different thickness materials and different radius bends. The hoods for the Mini-H, Mini-560 and Artie were all made of 16 gage material. 18 gage material is a lot easier to bend but obviously isn’t as dent resistant as the 16 gage material. A piece of 1/2″ all thread on each end is used to “pull” the 2″ diameter bar down between the outer rolls and bend the metal.
As can be seen in the pictures, one bend has been completed and the other bend is in progress. It requires some calculation and experimentation to determine where the bend should be placed to get the proper width hood. While the placement of sheet metal to obtain the required width can be calculated, the amount of “depth” for the 2″ bar to create a 90 degree bend has to be determined by experimentation. I always practice on a couple pieces of scrap sheet metal to determine where to place the sheet metal and how much to screw down the all thread.
The finished hood looks like:
The metal I used has a little surface rust. I waited until a day when there was no rain to order it, but the supplier must have loaded it the day before in the rain. It’s only surface rust and won’t hurt anything. Also, the hood is too tall and the sides need to be shorter. I’ll find someone with a shear to do that for me. I’ll make the “gas tank part” of the hood before determining that height.
As usual, if you have any comments or suggestions for improvement, just drop me an email. I’m always open to better ways of doing things.