A friend has a tubing bender that is giving us fits. In the past it has worked as would be expected. Bent all the 2 inch for my 31 project and some other smaller projects. Now we are building a banger engine exhaust and cannot get this thing to bend 1 1/2 tubing at all. Just flattens the crap out of it. We have tried several parts stores pieces all to no avail. Have cleaned the dyes so they are smooth and have oiled them up prior to bending. Still same result. Took the pipe down to a shop who has another older machine and it bends the same pipe perfectly. We are scratching our heads here for a solution to this. Anyone have more experience than us with these machines that can offer some advice?
Can you adjust the bender pressure up or down, and see if it helps? The bender where I work will bend tubing like that if the back gate pressure is either too high or low, cant remember which way??
The issue is there's no back shoe for these cheap benders, so the tubing isn't supported on both sides. So as your ram puts pressure downwards, it allows the center to pull away from the single shoe, and it begins to kink. The key to fixing it is to modify the shoe for the bender by making a back strap that's fitted to the tubing closely, and can be bolted or pinned to the shoe before starting your bend. The strap should be about 1.25"-1.5" wide, and at least 1/4" thick. Bend to a U shape, and leave the ends long enough to go up high enough on the shoe to get into the thin section. Then use a bolt or pin long enough to span the two ends. Be sure to use spacer bushings between the U strap, and the shoe so the bolt wont bend as you put pressure on the tubing. I modified all my shoes to add straps to take the same bolt and spacers, but different straps for each size. No more kinked tubing while bending.
To clarify let me say that while this machine is old (circa 1970) it does have a full compliment of dies and back shoes both 1/2 and 3/4. In this 1 1/2 case we are using 1/2 shoes in the back. I have not seen a way to reduce the pressure. I will look today. Thank you for the replies.
The Jalopy Journal
