The first version of the Colonel Rutherford model used a chain drive to transfer the drive from the motor to a gear rotating an airmail aeroplane above the model. I originally used a plastic snap-together chain that I bought from eBay. It worked well enough but some of the links were a little stiff giving the motion an uneasy, jerky look. Visuals are as important as how well the models work in these automata so I set about making an improved chain drive, this time using laser-cut wood. Here’s a rig showing the end result in action
Two of these pieces are glued together for each side of each link. A cocktail stick through the small holes is used to ensure everything is lined up properly then the pieces are clamped up and left to dry .
The cross pieces of the chain are made from 10mm lengths of 9mm dowel. I drilled the dowel through the centre making a pilot hole for the screws. The screws are fitted using appropriate washers and tightened just enough so that the links are flexible.