I had great fun designing and building this gearboard for a four-year-old who has become intensely interested in how things work and in carefully fitting Legos together.
It’s made of 3mm Baltic birch plywood. The board is two layers thick in the middle and a third layer forms the boarder. It’s 445mm wide by 355 mm high, about 17.5" x 14". As you can see, I’ve made the board from pieces that fit together like puzzle pieces and have alternated the direction of the grain checkerboard style. The border is pinned to the rest of the board using bits of 3mm dowel, just because.
The gears are also two layers thick. They’re fitted with 5mm Delrin rods for axles in the center and “skid pads” near their circumferences so that they turn smoothly and easily. They’re colored on the top surfaces using alcohol ink, and all the surfaces were then sealed with clear lacquer. In person, they – and the board itself – are quite chatoyant due to the grain in the wood and the lacquer.
I hope the recipient learns as much from playing with it as I did working on it!