Tech week thread Stamping shapes into sheet metal When I started my Model A project, I knew I wanted X shapes in the floor pans similar to factory stampings. After a couple of attempts with a bead roller, I knew that getting a nice-looking factory X bead with a radius at the corners would be difficult. <o></o> This I how I made a stamp to achieve the look I wanted. <o> </o>After some measuring of the spaces between the floor cross braces, I came up with 12 inches by 8 inches as my overall outside dimension. <o></o> I then drew a pattern in Autocad with a 12 by 8 X shape in the middle of a 15 by 11 rectangle (this was also my first use of Autocad). I had this cut out by a friend of mine with a CNC plasma table (you do not have to use Autocad or a plasma table; the same results can be achieved with a drill press and jigsaw/bandsaw, or a hand-held plasma). <o></o> After cutting my pattern out of ¼-inch steel, I had a male and female die. The plasma cutter cut width was about .080, making a perfect gap for the sheet metal to form into. I then made a flat plate the same size for the top and bottom to help spread the load of the press. After testing this setup, I found that I was not happy with the squared shape on the edges of the X. <o></o> I then decided to make a male die from round stock to fit into the female flat plate. This required cutting the round stock to length and rounding the ends. I used a lathe to round the ends of the X, but a sander would work fine. After welding the X together and building up weld around the inside corners, I spent some time sanding the inside radius. At this point, I was done testing and had gotten what I was looking for. I set the lower female down onto a platform and tacked the two together. I then used shims to align my upper male die with the lower. At this point, I had two large plates that were aligned to each other. I drilled both and tapped the bottom for ¼ course thread. I took the longest ¼ bolts I had and cut the heads off to make dowels to align the dies each time I used the stamp. I added some bracing to the whole assembly and used a shop press to press the sheet metal. I used 0.080 aluminum sheet for the floor pans I was making. continued...
Before stamping, I would mark out the area for the X and anneal the aluminum. I put a light coat of acetylene soot in the shape of the X and slowly heated the aluminum to burn off the soot. While the panel was still hot, I would take it to the press and stamp the panel. I let the panel cool while under the pressure of the press. I found that this helped minimize warping of this material.
Although I used some specialized tools this time, the first two dies I made using a drill press, band saw and hand-held plasma cutter. The Mustang pony I did by first drawing out the logo to the size I wanted and cut it out on a small band saw. I then tacked it to a flat plate and slowly traced the pattern with a plasma cutter after removing the tacks. I did some die grinding and sanding and set them up with backing plates and dowels, making sure to use thicker plates to spread the load of the press to the entire panel. This is the result.
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