Carving a skateboard mold prototype in foam. The mold itself will be made of laminated lumber to support the pressing process. This test was to determine what bit and step over (the overlap of each pass of the bit) would achieve sufficient detail, and not require too much finish sanding. The process and pattern for finishing is like an ink jet printer, but it cuts each pixel in 3D.
It may not be readily apparent in the photos of the carving, but the board has pretty complex compound curves. I’ll include a shot of the model which illustrates this better after the break.This is a shot of the roughing pass being completed. The test chunk is about a 1/3 of the skateboard’s total length, and the foam was a bit undersized so the board is a bit wider than what the foam could capture.
The model as rendered by the CAM software.
About halfway through the finish pass.
A penny sitting on the surface to show the level of detail. The “corduroy” look of the ridges is from the use of a round bit and a slightly too large step-over.