Double Pendulum Power

[vince]

@ nybtorque

I find it extremely strange that you have shown no curiosity or interest in my one arm build of your device. You have made no comment at all,not even to dispute it. I know that if I had a design for something and not the ability to build it I would be very interested in someone elses build of the device and their observations.
I'm not sure if you feel I have not captured the intent of your design or maybe you feel that a bad build will tarnish your predicted results.
Let me assure you that I understand your design and have implemented it into my build. Basically you are driving an outer pendulum( rotating offset weighted wheel) with gears or belts in my case via an inner pendulum which is free to rotate (occilate) around the primary driving axle. You are then harnessing the inner pendulum occilations for power.
When I first read your paper I felt you had a clever idea and was determined to prove it out for myself. I was going to build a 2 arm version as in your balanced design but I only had two matching gears and did not want to spend money on an unproven idea. I decided that the one arm version although unbalanced should net results in occilations to prove the concept.

My machine is driven by a 1/2 hp dc 5000 rpm motor with variable speed. There is a 1 to 4 reduction in speed from motor to rotating pendulum. If you hold onto the driven pulley that drives the rotating pendulum (that is after a reduction of 1 to 4) you can stop the motor with ease even at full power. It is not a strong motor at all. I did not post observations until now because I was testing different speeds and offset pendulum weights.
What I found was that indeed as you predicted there is a critical minimum weight that will begin occilations on the inner pendulum arm depending on it's design.
In my case the occilations began with 1/2 lb. at 2 1/4" radius. Speed was not as important in my observations as it started to ocillate immediately even at low speed. Speed however did make a huge difference in output power of the occilations. The amplitude of the occilations was hard to measure but it was somewhere between 1/4 and 3/4 of an inch at about 6 inches from pivot of the inner pendulum.
This is where a two arm balanced machine would shine . The one arm version would shake itself apart if not held down firmly.
Holding onto the ocillating pendulum it was impossible to hold it from occilating even with my full body weight leaning into it.
It is extremely powerful in it's ocilations.
The real challenge that I see is harnessing that small movement to a generator
To all you math experts out there I cannot verify my observations with math so I leave that to you to debate. What I do know' is that if you build this thing you WILL be impressed. 
Going to be looking for some gears or will make some to build a balanced two arm version. Hopefully some one will come up with a generator that can harness this power.
Hats off to you ncbtorque!

Vince

[telecom]

Hi Vince,
I'm very interested in your implementation.
Can you please post more pictures.
Thank you.

[LibreEnergia]

And no, this does not violate the conservation of energy principles. Because we're dealing with the derivatives of energy and speed, i.e. power and acceleration. Much more interesting if you ask me...

So tell me, what would happen were you to integrate those derivatives over time.. You'd be back to energy and velocity, and unless your analysis was flawed you would have a conservative result.

If a double pendulum contain pivots with friction (or generators) then you need to include a damping term into your simulation equations just like you would if it was damped simple harmonic motion. I'm not seeing that in your simulation.

The damping term would be a counter torque proportional to angular velocity at the pivot.

[telecom]

These people are using a very similar concept, except they make the output to rotate,
rather than oscillate.

http://www.universalengines.com.au/how-ue-works

The double pendulum always stops because they don't use a part of the output to
maintain the input speed. This can be achieved by  rectifying AC from the generator and sending part into the input motor, another part to lightbulbs.

[nybtorque]

So tell me, what would happen were you to integrate those derivatives over time.. You'd be back to energy and velocity, and unless your analysis was flawed you would have a conservative result.

If a double pendulum contain pivots with friction (or generators) then you need to include a damping term into your simulation equations just like you would if it was damped simple harmonic motion. I'm not seeing that in your simulation.

The damping term would be a counter torque proportional to angular velocity at the pivot.

You're absolutely right. But there's one big difference between integrating acceleration and power... acceleration is vectorbased and it changes direction as the pendulum is oscillating, so the velocity (and kinetic energy) never get very high... But, power is scalar and when you integrate you get energy regardless of direction. This is one key feature of the report. Probably not emphasized enough.