Engineers of the forum please prove me wrong!

[ShaydDeGrai]

Just 100%, over 100% is producing energy. But we don't need 100% efficiency right? Just efficient enougth to be amazing, like that contraption.

Now I wonder, if that is an estimated 80%+ efficiency, how much is possible with Lego? Is it possible to create something like that and have it running for minutes?

Back when I was a professor, I knew a research group with a big grant from General Motors to improve the efficiency of REAL cars, looking at everything from electro-magnetic bearings, regenerative braking systems, thermo- and piezoelectric transducer recovery systems, new engine designs, and hybrid engines to new alloys, body designs, battery technologies and adaptive computer AI to optimize shifting in transmission. They even looked at thin-film coatings for windshields to cut down the increased drag from driving in rain from the micro turbulence that forms around water droplets when the bead on glass.

Their goal was to someday get a real car to 30% total energy efficiency (assuming conservation of matter). That's not a typo. Commercial passenger cars waste more than two thirds of the energy that goes into them (usually chemical potential energy in the form of gasoline) mostly in the forms of heat, useless vibration, friction and deformation of the tires. The engine itself usually maxes out at 30-35% and the system as a whole goes down from there. As the research improves (and market forces will allow) cars get better, but they are no where near 80%.

In that context, I don't think LEGO beams that can bend, warp and otherwise deform with load and changes of heat and humidity, LEGO gears that - for a toy are pretty good but - really don't mesh all that tightly, and axles, bearings and pins that allow for local wobble and uneven wear stand much of a chance to come anywhere close to that goal. We might be able to exploit _a_ neat trick here or there in a Great Ball Contraption, but LEGO is hardly the ideal medium for a seemingly perpetual motion sculpture. Somewhere along the line you need to keep putting energy in to get motion out and the base nature of LEGO parts exacts a high "handling fee" in the middle.

As for the "art installation" in the video it does look like a high efficiency gizmo (and a neat sculpture) but I'm sure the moment you tried to tap into it to generate electricity, it would grind to a halt. The design itself reminds me of late 18th century clockwork designs that tried using pendulums to keep better time on ships (for longitude calculations) and makes me want to see if that guy's PMM functions differently at the equator than it does as a fixed installation in Scandinavia. Early pendulum clock makers discovered that their devices were "more energetic" in northern latitudes than they were near the Equator and modern research suggests that this was a function of the Earth's rotation and the gravitational tides of the moon.

If it _is_ the case where this guy has built a giant desk toy that is so sensitive that it can tap into the momentum of planetary bodies for noticeable extra energy (say through a forth, heavier pendulum hidden in the thick post in the middle), well, that's _really_ cool but it's still not perpetual motion, it's just hiding the energy transfer. In principle, it's really no different that a tidal generation station that uses the extreme high-low tide swings at high latitudes to generate "free" electricity - it wasn't really free, you slowed down the whole planet to get it, most people just didn't notice.

Edited December 23, 2013 by ShaydDeGrai

[aol000xw]

Disclaimer for picky engineers: Perpetual motion in the strict definition of the term is in practice unnattaible, contraptions like the one shown able to run even for years are not power sources.

So now how are we going to design a Lego perpetual machine?

[Boxerlego]

Disclaimer for picky engineers: Perpetual motion in the strict definition of the term is in practice unnattaible, contraptions like the one shown able to run even for years are not power sources.

So now how are we going to design a Lego perpetual machine?

There is a power source in that machine in that video and It is called a spring and that stores energy.

[aol000xw]

I think the guy in the video said the spring reacts to the conunterweights acting as pendulums allowing a slight balance of the wheel so the ball is always sliding down.

[Gee]

Fascinating stuff and this discussion shows everything I love about Technic and LEGO as a whole - it attracts inquiring, creative minds!

[Lakop]

Fascinating stuff and this discussion shows everything I love about Technic and LEGO as a whole - it attracts inquiring, creative minds!

Yes. I have a creative mind but I don't know if lego made me creative or was it my creative mind that attracted me to lego 35yrs ago. This topic is very interesting.

H

[piterx]

i think lego helps people who "born creative" to become creative for real XD

[Doc_Brown]

i think lego helps people who "born creative" to become creative for real XD

Agreed! :thumbup: