In this picture it could just be upside down, but if you look pictures on ebay and amazon, it's quite common for them to have the chain on backwards!

Yes, this is actually quite a common practice in hot countries, for seasoning timber also.

Yes, an R2D2 type droid is actually a much more realistic type of project!

@@AndysMachines If I were gunna make one, [and some day if I get rich I might], I'd go full tilt and make it as close as scientifically possible, to doing everything the movie version is purported to do [but was actually a midget in a robot suit]. I'd pack it with top end military spec sensors, world class processing power, a really powerful power cell, make the entire body from spun heavy gauge aluminum tube [1/2" or so], a spin turned heavy aluminum dome, and cast aluminum feet and arms, with real working hydraulics [including hydraulically driven wheels, in really walking legs. And, again, I imagine my version would weigh around 800 pounds, being made with all working components [which would be made mainly out of steel, aluminum, brass, bronze, and lead [as in lead acid batteries in the base of the droid]. That said, though, I would not be above putting in a small, but well muffled gasoline motor in there that spun an alternator to power the system, with only enough battery storage to buffer the system [as is the case in cars]. If I did have a gasoline type motor on it, though, since that would kinda kill the whole droid vibe, I would have to make it so quiet that it could not be heard as a motor, and would not produce the smell and smoke of a motor.

Some nice ideas! What about a hydrogen fuel cell instead of an internal combustion engine? Quiet, no fumes (only water), produces electricity directly and only needs a tank of hydrogen instead of gas.

Yes, It's kind of a special case! 🤔

Because a (flat) belt would have to twist 90° around the corner, which is possible, some car engines even do that, but bead chain can just bend in any direction and I liked that solution better. A round belt would also work but it wouldn't be synchronous.

Yes, some parts I have made on a CNC, most have been machined manually, and some have been made from castings produced from 3D printed patterns.

Yes, you could do that and it would save some cuts. You could even cut each side of the teeth with only one pass on a larger gear, but the saws would also have to get progressively larger in diameter up the stack, so that the outer edges form a cone which matches the pressure angle of the gear, otherwise they will not reach the teeth. It would be similar to a gear hob tilted over (to the pressure angle) but only cutting with one side of each tooth.

The problem with hydraulics is that it would also need a lot of valves, each one with it's own motor or solenoid, so it wouldn't eliminate them, just move them all to one place, and then there would need to be a ton of hydraulic lines to all the actuators, which are more difficult to route than electric cables, and a large pump and reservoir. Hydraulics are great for some applications, but I think this would just be a headache.