A large cycloidal drive, made by laser-cutting plywood and complicated geometry!
Cycloidal drives are used in industry, but are machined from steel to make high torque drives for heavy machinery. Cutting one from plywood was a rather novel approach.
Our expectation was that the laser could cut the shape visually, but a pleasant surprise was to find that the mechanism also worked so well. This is made from two layers of ¼" plywood, stacked to give a relief effect. The rear layer is solid and includes the spokes, the front layer is just a thickness doubler for the rim and it also has the "Waltz on the Wye" lettering laser cut through it. Both sheets aligned perfectly on assembly and only a little sanding was needed on the edges.
The design of a cycloidal drive involves some complicated maths. Andy Payne of CamBam, one of our favoured CAD packages, added it as a design tool.
Thanks to Russell Couper for motorising it.