How to Make a Simple Metal Roller Bender

I made a very simple and useful device for any maker which starts working with metal - a ring roller also known as a roller bender.

How I did it - you can check by looking DIY video or you can follow up instructions below.

For this project you will need:

Materials:

1. 40x40mm square tube
2. M12 thread rod
3. M12 round stock
4. Bearings 37mm by 12mm by 12mm Link here
5. Hex bolts, washers and nuts
6. 5mm x 40mmsteel flat bar

Tools:

1. Drill, drill press and bits
2. Angle grinder
3. Welder
4. any other various bits and bobs which helps to get job done in the workshop

The main roller structure will be made from this 40 by 40 millimeters square steel tube with 3 millimeters wall.

Measured and cut two pieces with 145 and 180 millimeters lengths.

Now its a time for a bit of measuring, marking, and drilling some holes. First I found the middle of the tube and then marked 3 places for vertical holes. Those will be drilled on both steel tube pieces identically. Also, all holes will be drilled all the way through.

Next, I flipped the piece by 90 degrees and drew the line with 13.5 millimeters offset from the tube side. Here I marked a pair of places for horizontal holes. Later on, you will see why such an offset is necessary.

In a local hardware store, I bought this eye wood screw. Not sure about the purpose it was made for, but I need just that round part which is exactly 12 millimeters in diameter. Also, I’ll use a piece of this M12 thread rod which I had from some previous projects.

I don’t like how the bottom part looks, so I marked and cut both sides in angle.

Metal rods on both sides will be acting as sliders, while the middle one will be generating the pressing power. The best way to fix them permanently is to weld them.

After the welding, I flattened the surface, because this tool will be attachable to the workbench and must have a flat bottom.

For rollers, I’ll use this kind of bearings. They are very cheap and are the perfect size for this project. 37 by 12 by 12 millimeters. And I will use 9 of them.

Each roller will be formed from 3 bearings and attached with an M12 hex bolt and nut.

Do you remember that 13,5 millimeter offset when I was marking the center for this hole? Here is the answer for such measurement - I no need to hold the nut with any tool, because the steel tube sidewall is doing it for me.

With an upper roller, the situation is a bit different. All bearing should be attached with a bolt, but at the same time, I need to spin the outer bearing part with some kind of handle. So I need to fix the outer part in one piece and will have a place where I could mount an handle.

And here is the solution - old pistons from car brake calipers. In my metal scrap box, I found these three. They are round, they are closed on one side and this one has almost 37 millimeters of inner diameter, which means I could press all three bearings inside nice and tight.

Before pressing bearings in I need to drill a few holes. One in the middle for the main bolt which attaches bearings in place. And four holes on the perimeter to attach the handle. Those four holes also were tapped for M5 machine screws.

All three bearing were pressed nicely with a vise.

The handle will be made from this 5 by 40 millimeters steel flat bar.

When all holes were drilled and the outer form was shaped I need to make one final step - to form a small offset that clears enough spacer for two bottom rollers.

The upper roller was attached as the two in the bottom with an M12 hex bolt and nut.

The handle will be held by 4 M5 machine screws.

And lastly, the handle was finished with an M12 hex bolt, a piece of PVC pipe, and a pair of nuts.

This roller bender could be attached to any flat workbench with a pair of clamps.

More pressure you will apply with the nut - faster the workpiece will bend. You could manage to bend just a bit to an arc, o go all the way to the full circle.

The design is minimalistic as possible, so If you need to bend bigger and thicker pieces - there is no problem to scale it up.