something new from YouTube:

Two-Stage Mechanical Oscillator Simulation
A simulation of a two-Stage mechanical oscillator using a motorized wheel instead of a pendulum.
http://www.youtube.com/watch?v=j2m1LbXuz6E

more...

Who asked for water pumping?!

two stage oscillator "casero"
http://www.youtube.com/watch?v=W_R-INBgZuo

Hi All,

You may be interested in the two stage oscillator that I built from Lego blocks.  Please see the Youtube videos at:

http://www.youtube.com/watch?v=MPNMzRGg_ow
http://www.youtube.com/watch?v=InUU08XD2YY
(or search for “Lego Two Stage Oscillator”)

All the Lego parts are from a Lego Mindstorms kit.  Non-Lego parts are the AA battery, the bronze bushing in the pendulum (both act as weights), and the rubber bands.  (There is nothing special about the battery and bushing.  Both were on my desk at the time, and weigh the proper amount.)

Why Legos?  Because they allow an inexpensive, quick, and easy to build model.  The model can also be rapidly changed to try different ideas.  Despite the “toy” aspect, the model here demonstrates the proper tuned operation that Mr. Milkovic describes.  It can also be detuned to operate with random chaotic motion, as well as untuned heavy lifting operation.  (You can see models operating in all these modes in other Youtube videos.)

If you choose to build your own model (which I encourage you to do), please read Mr. Lindemann’s Model Builder’s Guide article:

http://www.veljkomilkovic.com/Images/Model_Building_Guidelines_by_Dr_Peter_Lindemann.pdf

In short:
•   Add weight to balance the horizontal beam.  (This is my AA battery).
•   Tighten or loosen the rubber band to get the beam to oscillate at the same frequency as what the pendulum swing.  (This takes some patience, but is not difficult.)

Although it is unlikely to go overunity (low forces, high friction), this model is an excellent teaching tool.

Good Luck!

Hi Merg, the motorized wheel idea is pretty cool.  But the simulation would be better if they spun the wheel at twice the frequency of the beam.  Otherwise you get sparatic oscillations like what you see in the video.  The pendulum makes it easy for the system to act parametrically, but a motor wheel would have to match frequencies. 

I like the lego oscillator.  Neat idea letting the battery power it 

The Milkovich- with-rotating-wheel was put on youtube at my request, by a friend from the Bessler Wheel website. I am unable to do simulations myself. Having seen the video, I suggest the following mods. The restraining stops need to limit the up and down movement of the wheel to about 5% of the wheels radius. Wheel needs to run faster, to increase centrifugal force. Lever needs to be about 3 times as long at the end carring the balance weight. Use a bike wheel with a freewheel [ratchet] sprocket. As the wheel jumps up and down, a static chain device ads feedback to the wheel. More detail on this if anyone wants to build. Can anyone tell me if it is possible to determine input/output ratio of this device from s simulation please ?