I’m trying to design a gearbox for rotation of an arm carrying somewhere around 11lbs and have pretty much settled on 35 chain and dead axle. Would having two sprockets on the driving axle and dead axle be the proper way to do this, that is to say one motor running a live axle with two small sprockets on it going to the arm joint, or would one set of sprockets suffice?
One set of sprockets will suffice.
Another thing to keep in mind is the larger the sprockets, the less strain on the chain.