Solar Tracking - Chain Drive Option.
Construction of the Chain Pulley..
Using std (1/2" link) bike chain. An 8 tooth gear is 4" circum. (102mm)
The 8 holes are 7.5mm. - the radius of the 8hole circle is 102/ 2pi = 16mm.
Construction of the 'Motor Head'..
above - the main pieces of the Motor block are 19mm dressed oak.
The Motor box (above) is 4mm marine ply.
The main pulley and 2 guides spin on 6mm 'coach screws' with a 0.3mm alumin. sleve.
The axel holes are drilled 6.3mm (1/4")