Hacker News new | ask | show | jobs
by toast0 1565 days ago
For a washing machine especially, the inefficiencies of turning mechanical energy to electrical energy and then back are going to be be pretty bad. If you could work out gearing to spin the tub mechanically, it might be better, although the back and forth motion of agitation isn't something I'd know how to do. Pumping the water and spin dry should be relatively simple, although getting enough speed for effective spinning may be a challenge.
4 comments
pitaj 1565 days ago
> although the back and forth motion of agitation isn't something I'd know how to do

A smaller wheel linked to a larger wheel, where the smaller wheel is driven by the bike. As the smaller wheel spins, the linkage will move back and forth. If the second wheel is sufficiently larger, it won't be rotated enough on the push stroke for the pull stroke to complete a rotation, and will oscillate instead.

https://imgur.com/B1ykmpB

link
kube-system 1565 days ago
This still assumes, however, the perspective that a spinning tub is ideal. It's convenient when you're starting with rotational motion, like with a motor. But if we're looking for the most efficient way a human could power it, I'd suspect moving the clothes across a washboard with a static tub is way more efficient. It also has zero moving parts, outside of the human itself.
link
masklinn 1565 days ago
Mechanical washing machines were a thing before ww2. You might be better off finding one in an old barn and replacing whatever it uses (likely a crank) with a PTO you can link to a bike. Adapting a modern washing machine would likely be quite a bit more difficult.
link
aliswe 1563 days ago
a bit perhaps. but the drum is always connected to a belt that has a motor on the other end. and a washing machine is full of metal framing which you can drill and screw stuff to.

the hardest part would perhaps be to reenact the water cycle?

link
rolph 1565 days ago
>>back and forth motion of agitation<<

apply torque in bursts, let the inertia help you.

start turning the drum and contents stay in place, while drum turns, until contents match speed.

then stop torque , so the drum slows suddenly and contents continue to spin until they slow down.

the drum doesnt change direction, only the direction of momentum, and the mass transfering the force does

link