I have two windmills on the sides of a large gear with the power train going down the tower, connected to the side of another large gear.
For my third windmill I tried attaching it to the centre of the input large gear's axle, hoping for a speed increase to supplement the torque gained from connecting to the sides, but found it made no difference to the speed of the central axle.
I know each axle and connection increases resistance, and having 4 machines working off the central axle requires so many connections that I wonder if the resistance from the convoluted maze of axles and transmissions is worth the squeeze.
Is it better to have 4 windmills just powering each machine on their own, or to combine power along a central shaft?