Introduction: 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.
Step 1: Step 1: CAD and 3D Print Models of the Wall-mounting Crystal and the Coat Hook Crystal
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.
Step 2: Step 2: Make Pattern Board
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.
Step 3: Step 3: Ram Up and Cast
Ram up over your pattern board to create sand impressions to pour molten metal into, then pour the metal into the sand mold.
Step 4: Step 3: Hack Off Different Castings
Step 5: Step 4: Machine Crystals for Screws and Press-fit Dowel
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.
Step 6: Step 4: Sand, Bead Blast and Paint
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.