60° Fold Foamboard Cutter

thingiverse

I am about to make some foam-board RC planes with a triangular fuselage. I have a number of cutters, but none that make a 60° cut. This is not strictly a re-mix (since I implemented if from scratch in OpenSCAD), but it was quite obviously inspired by: https://www.thingiverse.com/thing:2779157 To use this, draw a straight line where you want the fold. Lay a straight-edge along the line and pull the cutter along it. Then switch the straight-edge to the other side and do the same thing again. You should be able to pull a triangle of foam off the paper on the down-side of the foam-board. The two pieces should fold onto each other making a 60° angle. I've found it's best to use a thick straight-edge (like a plastic right-angle) to keep the cutter from riding up onto the ruler.