While I’m prototyping the gears on my wooden automata I need to be able to assemble and disassemble the model so that I can experiment with designs.
I’ve tried all sorts of design variations. Brass axles, grub screws, flanges, perspex joints. Finally I feel like I have settled on a consistent design. I’m using 12mm dowel for the axles and a keyway in the gear’s axle hole to hold the gears in position.
I drill a couple of small holes in the dowel in the place where the gear is being fitted. The holes don’t go all the way through the axle. I then make a curve-topped staple from a short length of 1mm diameter wire.
The staple fits into the two holes, the fact that it is curve-topped ensures that the centre of the staple is raised above the dowel.
The gear then slips onto the shaft with the keyway located over the staple. The staple works to stop the gear rotating out of position. Perfect!