Laser Cut Wooden Chain and Sprocket

chain-a12The 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

chain-a01I cut out lots of little pieces on the laser cutter to construct the chain. For simplicity each link of the chain is constructed from four identical pieces.

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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 .

chain-a03Lots of links are needed!

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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.chain-a06

The sprockets are made from three layers of 3mm ply glued together.I sanded the side of the sprockets off to help guide them into the centre of the chain.chain-a07

Here’s one of the finished sprockets showing the tapered teeth.chain-a08

This version of the chain drive is a test bed to ensure that it works properly. I’ve mounted the two sprockets onto an MDF baseboard and added a handle. Looking good!chain-a09

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