I finally found the time to create this patter for sand casting a giant quarter of aluminum in our high school metals shop. The pattern is 6 times the size of a real quarter. Brady Watson has a laser scanner and offers his services for a reasonable fee. It must be a very cool toy, but I am pretty sure I couldn't afford to buy one. Instead, I had him scan the quarter and send me the 3D file in an stl format. I then used DeskProto to generate the toolpaths and NC code. It was machined from Renboard, which is a cured plastic material used in mold making and prototyping. We are fortunate enough to have a local company that uses this material and donates its leftovers to our school.
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