Thank you all.
Hello Jamie, Ron and Jim,
This is all very helpful. Great photos of your #10, it explains a lot. The fan shaft has an internal thread. It appears that each fan has a machine screw with knurled head inside the barrel and is permanently attached to each fan. Are the fan blades press fitted into slots?
Ron, do you use free machining brass for your gears? Is the large ring gear cut from one piece of stock, or formed from an over-sized strip, brazed and then machined? Is the brass ring gear durable enough to use without plating, that is, do you know if anyone has got any amount of use out of an unplated one before wear becomes a problem?
Jim, this camera you sold me is getting expensive.