3D printed Dimple dies for sheet metal shaping
Channel: Classic-Car.TV
Date: 07/05/2020

Round beads serve to stabilize metal sheets. The creation of such circular beads can be made very easy with a 3D printed dimple die.
When printing with PLA or nylon, all you have to do is make sure that the wall thickness of the printed models is around 3mm and the inlay arround 40%. This guarantees enough stability to even shape sheet metal steel. Several sizes can be printed in one pass. Due to the stable structure of the printing stencils, 3D printing takes quit long. In our case, almost 4 days.
At the point, where the circular bead is to be formed, the sheet metal is pre-marked with a punch. First of all a small hole is drilled. Then drill a larger hole with the tapered drill. A hole cutter is used. The cut hole must be just large enough that the narrowest part of the punch can be used. By tensioning the punch press cuts a corresponding hole in the sheet.
The sheet metal is placed on the punch in a press. The counterpart is put on. Now the entire package is put under pressure. Alternatively, the punch can also be driven together with a hammer. The punch fits together perfectly and presses the sheet into the negative shape. When opening the punch, you can see the perfectly shaped bead with a rounded edge.
The process can be repeated any number of times. Such rounded beads make a metal sheet very stable. The thin sheet shown here can hardly be bent. In comparison, the sheet without the beads is very unstable. The bead punches can also be used for steel sheets up to 1.2 mm. The procedure here is the same as for aluminum. Only more pressure has to be applied.

An additional ring and a trough in the counter part provide additional stability. Here, too, a high wall thickness in the printed punch is very important, so that the tool made of PLA or nylon receives the appropriate stability. In our case it is 3mm.
Here, too, the lower part of the tool is placed in the press and the pre-drilled sheet metal is placed on it. The second half of the tool comes last. If the pressure is now applied to this package, the template slowly pushes together and presses the sheet into the desired shape. Ultimately, the ring presses the sheet into the trough. This must not be done too quickly or with too much pressure, otherwise the sheet may be cut.
 
If you separate the two tool halves, you can see the raised circular bead around the pressed bead hole. Such beads can be made in different sizes.