Monday, April 27, 2009

Home Made Metal Bending Brake

To help improve the accuracy of what I am building, I decided to put together a simple sheet metal bending brake. It didnt have to be too fancy, or able to bend thick gauge metal - just needed to be simple, convenient to use, and somewhat accurate.

So here it goes...

I had seen several home made bending brakes on the web - but most were built with metal bits all welded together. Often used for building home made aircraft bits.
I dont have access to welding kit - so mine needs to be a combination of wood and metal bits where necessary. For some reason I liked the idea of using angle iron.

Starting off in Sketchup as usual...

First idea was for a press bending brake...


However the building of this would be a little more complex - and I figured that it may not work as expected - too many unknowns.

Second idea, more conventional, as as follows:


With this one, the angle iron on the left is to be held in place with simple G clamps - the sheet metal goes underneath this piece of metal. The iron on the right is attached to a piece of wood that rotates on two door hinges, rotating upwards to bend the metal. With the left piece of angle iron, it can be positioned in two ways - firstly with the 90 degree angle on the bend - which would give a sharper bend, and then with the open end (as shown in the diagram) against the bend, which allows you to go past the 90 degrees.

I decided to go with the second brake.

It only took a couple of hours to put together... the results as follows


After doing a few test bends on some light weight iron, the results were OK. One shortcomming with the design is that the top piece of angle iron tends to slip backwards as you bend - the G clamps need to be tightened quite tightly.
To improve the design I will screw two L shaped fastening brackets at the edges of the base piece of wood - the top piece of angle iron will sit on these brackets and help to hold it in position.


So that is what it looks like - need to go and buy some new sheet metal for building the HTPC case next, and test out the machine with the real metal.

3 comments:

  1. How well did the brake end up working?

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  2. works OK on thin sheet metal

    the larger the sheet, or as thickness or stiffness increases, it begins to suffer.
    there is give in the wood. if you replaced the wooden frame with something metal, would be better.

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