Considering just the driver at different radii: at a smaller radius, the torque the mass applies, and the time it takes to do so vs friction probably plays an important part here.The large radii spinning mass has a better wind up rate than a small radii: 50% vs 33%.
So it seems that a spinning weight at larger radii is better suited to collect and save energy...
Why is that?
1. If it takes longer to unwind, the friction partakes for longer, sapping more energy.
2. At a smaller radius, your torque vs friction ratio is different, so I would expect a poorer drive effect at smaller radius.
There are probably other factors I have missed.
I have tried to drop on the outer, and lift on the inner, and vice versa to see if I can get an increase in energy, I have also let the mass change pulleys half way so the mass's inertia from standstill is less of an effect. Fletcher gives good advice. If you think you have something interesting or abnormal, post good pics and a vid for accurate feedback.
Cheers (wff)T