I think that the bit the metal bends against should have a bevelled edge at say 45 degrees rather than 90 as you have it. This allows you to bend for the "plus" bit to allow for springback.

You will never make a 90* bend unless you over bend by a small amount 3-5*. Youngs modulus of elasticity or some such ! So having a a stop at 90* will always give a smaller bend. If you measure the bend you have, then add the short fall to 90* you will be pretty close. Good luck, Noel.

I reckon that the purpose of the angle-iron is to securely clamp the workpiece, but you are using it as a bend stop. I suggest to reverse the angle-iron and machine a bevel on the edge close to the bending point. Then make a separate stop to limit the bend amount.

I assume the angle iron is locked down with the 2 screws to hold the plate in place, to be bent. Once you have done the bend. Release the hold down angle iron & draw the angle bent piece through a little further. Clamp down & re-bend. You will achieve the angle you want.

Only problem with this method is the radius of the bend will be greater & allowance will have to be made with sizing the material.

Steve.

Most DIY benders have the clampling angle "upside down" so that the two edges clamp the part and then there is room to over bend the part.

Peter

Hi, I made a 1M long one in my last job, Which had a piece of 100 x100 x 12mm angle and like pgk pgk says, the apex was uppermost so it had a 45 degree backwards fence. The two outside edges were machine back though where it clamped the sheet being folded, so it had just a very small radius for the bend. The angle also had a 30 x 70mm piece of flat bar tack welded inside the angle, which helped it from bowing during folding and a block was welded on each end of the angle for a sloppy 24mm bolt hole for clamping it down, the sloppy hole made for a bit of adjustment for different thickness metal. We could, with a bit of a grunt, bend a piece of 1mm 306 stainless steel, about 800mm wide in it, but it would do ally up to 1.5mm thick the full 1M wide. It was made to be bolted down to a heavy steel bench. Yes you will always get a bit of spring-back, even on a break press.

Regards Nick.

P.S. on reflection, the clamping blocks welded on each end of the angle, were in fact thick oblong box sections.

Edited By Nicholas Farr on 07/08/2021 15:55:29

Yep what Garry says, the angle is really only to stop the clamping bar bowing, rotate 180deg so vertical leg is away from the bend and mill or file a chamfer on the edge of the flat leg

It won't mean a larger bending radius.

Edited By JasonB on 07/08/2021 16:27:30

Edited By JasonB on 07/08/2021 17:08:21

+1 for overbending, so that then metal springs back to 90 degrees.

A bit of "suck it and see" until you get to know how much to over end to get the required angle.

Will probably vary from material to material, and the thickness..

File under "Experience", unless you are like me and have a good ability to forget.

Howard

No, The work is clamped by the larger angle on the top held down by the two extended wing nuts, bevel can be seen on this angle.

The smaller angle on the moving part is just the way the bender is made.

Full details of that folder here

If that a ngle is hot-rolled it will have a radiused edge, so having reversed it so the upright is at the back, you might find it won't need chamfering.