What a simple answer! I would call myself stupid for missing this, but a whole bunch of very smart people also missed this.
Maybe it was the way I originally phrased the question. I wanted two motors working in opposition to each other. So there was a torque on both shafts S1 and S2. The...
The ratio is something like 10 to 1 (10 turns of S1 correspond to 1 turn of S2). It is a system of four gears, one pair is helical, and the other pair is spur. (So there is a third intermediate shaft.)
But I have another example whose ratio I am not totally sure of, and it is all spur gears...
I have a gear system, where one shaft S1 drives a second shaft S2. The gear system works equally well whichever direction I turn S1.
Now I want to turn S2 to drive S1. I find that the friction becomes quite a bit greater.
I did quite a bit of web searching, and I also asked Mechanical...
