Jhula principle - increase speed by applying brakes.

[xnonix]

hey prajna,
I modified the lever and pendulum masses. Now it works with an air resistence of 0.3 or more.

I only take reads of rotational speed in this case.

Have fun!

[prajna]

@xnonix: That is fantastic. I think that there is further optimisation to do in terms of biasing the system so that disadvantageous forces from the pendulum are reduced and advantageous forces increased.  This is a matter of slowing the pendulum at the correct moment so that its maximum swing force (cetrifugal force) is alligned at 90 degrees or less to the centerline of the counterweight.  It is all a matter of timing.  We have got it half right with the latching mechanism at present.

@bluesgtr44: You are right, gravity does always want to win but here we are playing off centrifugal force against gravity and gravity wants to win over not one but two centres of mass that are tied together and oscillating about each other.  When gravity adds momentum to the system we accept its effort gratefully and when it is being a nuisance we trade some angular momentum to counter its effects.  That is the principle that we are aiming at here.  We are basically swapping energy from one part of the system to another and looking for a formula that will allow us to always move the energy 'uphill'.  That is a matter of timing the maximum centrifugal force so that it is at a useful angle to the overcentre of the two bearings and so that it seldom occurs when the pendulum is more in-line with the axis of the counterweight. That timing can be effected by retarding the pendulum swing at favourable moments.  Sure, we lose a little momentum on the pendulum but we have traded that for applying that force at a greatly advantageous point.

You are also right that there was no (or very little) air resistance in the model but when we are examining the effect on a theoretical basis it is considerably easier to see if we have a net gain of momentum if such energy sinks are removed from the system.  Yes, a practical system will have to take air resistance (and many other factors) into account but a theoretical model is considerably simpler when we leave them out.

[xnonix]

The latching system is good enough as is now. We know the system is accelerating. We can construct it in real with easy off the shelves parts and no logic.

We need the mechanism (2 of them) of the rear wheel of a bike to construct it.

One aplication for fun:

[prajna]

xnonix, I'm very impressed! Nice model. Sure we have acceleration at present and we are using straight mechanics with no other logic but does it not appear to you that there is a heap more energy available from this system if we can increase the asymmetry? We capture a little more of the gavitic effect on one side of our cycle than the other but there is a strong centrifugal force that sometimes adds tons of angular momentum to the system and sometimes robs it of an equal amount. Perhaps there is a simple mechanical way to bias this equasion too.

[prajna]

xnonix, I've taken your model, dropped it to the floor and reset all the velocities to zero. It still works after that dreadful abuse and shows acceleration.