CNC & Molding and Casting

1. Design something and make it using CNC. You may use the ShopBot (2D outlines), the Shaper (2D outlines) or the SRM-20 (2.5D molds).

2. Create something by molding and casting.

This week, I wanted to use the CNC machine to cut out a jewelry dish in the shape of the Hawaiian plumeria (which Cassia later called "the spongebob flower looking thing"). To do this, I designed a simple 2d sketch of the flower and the sketch of the inside. I overlayed a simple image of the flower for reference on the plane.

Once that was complete, I brought the dxf file into the shopbot software. I wasn't able to get photos of this process, but I'll try to briefly describe the process. The work piece is secured to a sacrificial layer of wood on the shopbot and is held down by plastic nails. I did an "air cut" to see if the tool path was correct, and then adjusted the CNC machine to the piece of work. To make the dish shape, I set the inside outline to the "pocket" setting, cutting only through the first couple layers of wood.

The CNC machine cuts layer by layer (sort of like a backwards 3D printer).

After cutting out the piece, it was quite rough, so I took it to the belt sander to smooth out some of the edges that the CNC was not able to do well. Overall I was very happy with the result due to the simple design. I then put the cut piece into the vacuum former to create a mold.

I messed up the first couple of times using the vacuum former -- turns out turning on the vacuum while waiting for the sheet to heat up was not helpful :/

Finally, after the vacuum mold was ready, I poured plaster decorate with a bit of purple dye into the negative vacuum mold to recreate the positive model of the flower dish.

Here's the final result! Works very well to hold my rings and earrings.