Two of the best arguments in favor of 3D printing are local production and product customization. This is particularly valuable and useful for old or outdated machines/objects that are too hard or expensive to get, or simply that one cannot find in the market anymore. On another perspective, by printing a part at home you minimize the carbon footprint associated with producing and shipping the part. Also, if the repairing is successful, we may as well be able to avoid throwing out a perfectly working thing and having to buy a new one. This is what happened when our good friend Fausto turned to us asking for some guidance on how to print a replacement part for his old machine.
Fausto wanted to try fixing his old food slicer, a machine he had kept for years. The motor was working well but the plastic gear that was attached to the steal blade was damaged. He though "Maybe I can print it", so he sought to contact us and we gave it a try. A good test for our Minmi printer.
We first needed to disassembly the slicer and carefully detach the part from the blade. As you can see, there were some worn out teeth, not allowing the blade to properly rotate.
Next, it was necessary to draw the part. For this we used our favorite CAD program - OpenSCAD. We used the involute_gears.scad tool from the MCAD library.
Then, we proceeded to the print step using our favorite 3D printer - Minmi.
It all went quite OK, the 1st trial was fitting reasonably good. But, because it was a tiny loose, there were a few dimensional adjustments to be made. After re-assembling and testing, the 2nd time worked like a charm!
Fausto managed to get his food slicer working and no need to buy a new one. Here he is cutting bread for lunch.