Cast Crystal Coathooks

This was my first machine shop project. I'd never used a mill, a drill, cast metals and this project turned me on to all of that. This project's photo documentation is a little sparse, (didn't think to document, duh) but hopefully I can supplement with text and CAD to show you how I made these.

I used Solidworks to make 3D models of the coathooks. I made planes at different angles to to create cut features that made the facets. The big crystal will need to be split in half for the casting.

This is the board that you will use to make impressions in the sand which molten metal will be poured into! Everything must have at least 5% draft and no sharp corners. You can use wax to add a fillet on all edges and corners.

Ram up over your pattern board to create sand impressions to pour molten metal into, then pour the metal into the sand mold.

The third picture shows the countersunk holes clearly. There's a press-fit dowel pin between the top and bottom crystal. Those holes were undersized by 0.001" to create the interference fit between the dowel pin and the crystals.

I used Montana spray paint in three shades of blue. I sanded to about 400 grit and then bead blasted everything. Assembled it and then covered the coathook crystal with blue tape to prevent paint from covering it.