The word brake in English has at least two meanings. One is the device used to stop a car; but the other has to do with bending sheet metal. We are here to understand the second meaning. A brake is then a device to bend sheet metal. Also, I am not going to tell you why I am bending all this metal. It's a Christmas present, OK?
Now bending sheet metal is easy. Bending it along a perfectly straight line is considerably more difficult. The catalogs will sell you all kinds of brakes to do this bending, for $100 and up. But, thanks to Dave Gingery's book Sheet Metal Technology we can do it with three pieces of wood. I am, as usual in this season, making miniatures; and furthermore I am using sheet copper. Copper is an unusual metal here in Alaska, but I found a lot of it in an antique store some years back, and it is much easier to work than sheet steel or even brass.
So what we need is three pieces of wood, in my case some house trim I picked up for free somewhere on my walks.
These pieces are 90x70 mm -- the second dimension approximate, it is no doubt some RGU. The three pieces have one edge planed absolutely square; most trim has rounded corners and you don't want that at all. Two of the pieces are connected with a hinge. The best thing would be a miniature piano hinge, but it would be easier to find emu eggs in the bush here than a piano hinge of any kind. So I used the old Alaska standby, duct tape, for a hinge.
Now, to use this thing, take your sheet copper and carefully scribe it where you want the bend to be. I use a carbide-tip scriber, but if you are doing copper you can scribe with a knife, such as an X-acto (tm, of course) knife. Then very carefully align the scribe mark with the edge of the lower piece (previous picture). Put the squared edge of the third piece on top of it and align it with the scribe mark, even more carefully. Correct it, because everything slips. Now clamp the lower piece and the third piece together. You have a sandwich of copper between two pieces of wood.
Now bend up the top hinged piece to 90 deg. and, if you aligned it all perfectly, you will have a handsome 90 deg bend in the copper sheet, right along the scribed line.
The weak point in this device is the duct tape hinge. I will keep my eyes open (and consult the internet) for miniature piano hinges. In case you are wondering, a piano hinge is just a very long brass hinge; it is used for piano lids and hence its name. But duct tape worked very well for me today.
What was not so hot was the fact that power went out at 1145 and did not come on until 1733. In fact it went off again, very briefly, while I was doing this post. Such is life in rural Alaska, AKA "the bush." If you don't like it, don't live here! Soon I will do another post on the perils of power out.