I could not get the part to fill. I kept getting cold-shuts and non fill areas. I talked with the customer and we made some design changes. We added a rib down the center between the runners, we made the flange symmetrical in shape and we added some small ribs on the outside of the part. Here is the new CAD model.
Here are the new runners cut out. I made the center rib hollow to allow the metal to flow thru the part without having to burn up so much foam.
The parts all glued together. The pockets on the flanges are where the runners attach. I once again wanted the aluminum to have as little of foam to burn out as possible.
The foam as covered in 15 minute drywall mud and allowed to dry for a day.
See part 3....Making the casting.