After you bend both sides the length of the roller holder will be inch longer than the longer rubber part of the two bottom rollers.
How to bend aluminum sheet into a circle.
Mark the bend point at 2 and inches with a chisel and bend both sides of the holder down using a piece of 2x4 to help keep the bend even.
Insert your aluminum sheet into the brake beneath the removable clamp bar.
Use scissors to cut the foil into a large circle shape.
To do this the extruded section is wrapped around a die.
Then place the clamp bar back down on top of the aluminum crosswise.
Step 3 cut a large triangle about one quarter the size of the circle out of the aluminum foil by making two cuts that run from either side of the circle to the exact middle point of the circle.
Methods of bending aluminum extrusion unlike bending metal sheet on a press brake when bending extrusion the goal is to create curvature.
Lift the clamp bar away from the rear of the brake frame and slide the sheet in perpendicularly to the direction you want to bend it.
Then use your bend allowance to draw your second bend line the intervening distance between your bend lines bend radius.
Now that you know your bend allowance take your protractor and draw a clear line with your marker across the point at which you will bend your sheet metal.
Make sure the bar is seated firmly inside the frame.
Mark your bend lines.
Take a piece of metal pipe on a hard surface and roll it over the sheet metal strip as you work it circular by pulling up on it.