I'm trying to find a way to lower items 1-5 lbs about 30 feet in 5-15 seconds. The challenge has been doing this automatically in a controlled manner, without having to manually reset it, and without resorting to a microcontroller. (people add/remove the items from the top and bottom though)
(I'll ramble why in a comment)
I have abandoned most constant sources of drag and those that require a user to manage the lowering or else let the load run away or slow to a stop.(i.e. a munter hitch, multiple wraps around a static bar, fishing rod drag-washer-stacks).
so far I'm not convinced I have a good answer:
-governors; without a 'throttle' to adjust I don't know if I can get enough braking force out of these
-dampers; having trouble with static friction in ones that want to spin fast i.e. eddy current damping, driving a dynamo. Alternatively having trouble finding an appropriate slower damper and speed reduction to go with it because the mechanical advantage makes the resistance curve to the load essentially flat or they heat up and de-tune (i.e. viscous fluid rotational dampers).
-escapement mechanisms; too slow, bulky, and/or not easy to reset. Also concerned with bouncing upsetting the mechanism if using mechanical advantage to lower faster but I haven't tested this yet.
Another problem I've had while prototyping is the rope slipping on a pulley. The idea being that one end would be pulled up to a ready position when the other reaches the bottom. Using two opposing spools fixed to the axle solves this