The tiniest push on the gear on the left causes the gear on the right to fly at thousands of RPM. Of course, there would be a ton of friction in the system to overcome. However, what if the left gear was a pinion connected to a rack that was pushed by an extremely powerful, yet slow-moving source, such as a glacier or tectonic plate? With enough gears in this arrangement, an unstoppable force moving just 1mm/year could spin tons of turbines.
Would this work?
Alternatively, you can use it the other way. Connect the gear at left to a tectonic plate. Rest your finger on the gear at right. Voila! You can exert a force great enough to stop the tectonic plate's motion. Plausible?
When Archimedes said, "Give me a lever long enough, and a place to stand, and I'll move the Earth.", he actually meant something more like, "Give me a lever long enough, and a place to stand, and I'll change the momentum of the Earth very very very slowly. Unless that lever is incredibly strong and I have access to a considerable source of energy."
Nope, the question here would be whether the material used to construct the left gear withstand the force that a tectonic plate exerts given that the gear system will not allow it to move. I don't think the mechanics of the tectonic plate exerting force on our gear system and our gear system exerting force on the tectonic plate are symmetrical.
Now while that implies a rotation of one degree of the first axle is accompanied by a rotation of the penultimate axle through 20 or so revolutions, in practice that's not going to happen, because of that ton of friction you pointed out. The friction force acting to stop the last axle turning gets fed back as resistance to your pushing the first wheel, and it gets multiplied back up through the gearchain by the same factor - so the resistance to your turning the first wheel is 7000-times the resistance of turning the last wheel - plus 2000 times the resistance of turning the wheel before it, plus 918 times the resistance of the wheel before that... in total, assuming all friction forces are equal, you're fighting against a force 12000 times the force you need to turn just one gear - just to beat the friction. Okay, so you posit some frictionless maglev bearings in a vacuum, perhaps. But you still want to get these wheels into motion, so then the same multiplier gets applied to the force you need to accelerate the mass of each gear into (rotational) motion in the first place. Getting all those gears spinning requires 12000-times the acceleration to get one of them turning, so 12000 times the force.
And forget about putting a useful load on the end axle - let's put this thing in a car, say, and use it to drive the rear axle. We'll lift up the rear axle and get the engine up to 5000 RPM. Your engine is going to get that axle spinning 7,000 times for every engine RPM - 35 MILLION revs per minute! But when you drop your 1-ton car to get some traction, the engine's going to act like the car weighed 7000 tons...
You could also think of it in terms of energy. If that last gear spins at thousands of RPM, its got a huge amount of kinetic energy from somewhere. It must have come from your 'tiniest push'. Your tiny push has to transfer all that energy - so it can't be that tiny.
But the main thing they do is let you trade angular distance of motion against angular force, or torque - same as a lever does, and much like how a pulley system lets you trade off linear distance of motion against linear force. I can make a gear system that multiplies the effective force I can exert by 50, at the expense of my having to rotate a crank on the input shaft fifty times for every time I want the output shaft to rotate. Or I can use it the opposite way around and make an output shaft spin fifty times for every rotation of my input shaft, at the expense that I have to exert fifty-times the force to overcome any load on the output shaft.
Edit: Thanks to bockris for pointing out the name. Turns out the last gear rotates once each 13.7 billion years.
I wonder if you could make a purely mechanical solar panel that way. Get a giant sheet of metal, put it out in the sun, and attach this gear arrangement to it, braced by opposite sides of the expansion. Hmm... I kinda want to make this now.
 - http://en.wikipedia.org/wiki/Kardashev_scale
The right wheel would spin fast, but anything put there to leverage that momentum into energy, be it simple magnetic generator, would be enough to halt the whole system by equalizing the opposing forces, since whatever minimal force it has, will go trhu the same powers that create the initial speed.
2. Is there a ready way to simulate it?
Also, there's a UI limitation with snapping concentric gears together: you can snap a small gear onto a larger one, but not the other way around. This seems to make it impossible to add a pair of concentric gears whose smaller gear is meshed with the edge of an existing gear.
But overall, great project with very pleasant casual interaction. Would be interesting to see what you plan to do with it.
The ability to save a configuration and share it would be pretty cool, but as well as that, other objects such as sticks which are attached to gears would be a lot of fun. But then I suppose you have to involve gravity :)
Overall I'm impressed.
can't even draw a square with the clitmouse...
I'd love to be able to make more complex gears. I immediately tried to make a compound gear set with three gears and two different bands.
That got me thinking about "Incredible-Machine" puzzle features and how fun it would be to actually try to build working things like clocks, bikes and machines with this.
Any plans to add more complicated gear types? Would love to see something like this enabling easy explanations of watches and the like..
Don't let their old school-ness throw you off. They are both extremely well done and demonstrate in clear and simple language from first principles to finished object.
It was of course more like an electronmechanical clock since there isn't a way to build a balancewheel and escapement, but since I had to eyeball the gear sizes and draw them with my mouse anyway, it now appears to be approximately 0:65:101am.
- draw involute teeth forms
- allow non circular gears
- add other linkages
- plot force (torque) and velocity (rotational velocity) against time or position
That would be a pretty slick tool for some quick back of the envelope type calculations.
In the intro of the book Seymour A. Papert describes how gears provided an early concrete framework that made understanding abstract mathematical concepts presented at a later point much easier to visualize and apply.
Also having the play button toggle pause/play would be nice.
I learned a bunch by watching the demo (big ? on the right)
Do you have a TODO features list? I don't know Coffeescript but this would be a good learning experience for me. I can think of at least one feature I would like to add.
I'm using the GearSketch environment in my PhD research to study different forms of support for learning about gears. For instance, I created a puzzle generator that creates concrete gear configurations based on abstract descriptions (e.g. there are two unmovable gears, one larger than the other; goal: connect them in such a way that the large gear will turn faster than the small gear). Using each student's solutions to earlier puzzles, the software tried to model their individual understanding of the gears domain and create new puzzles based on that. Turns out accurately modeling student knowledge is hard. ;)
The students using GearSketch are 10-11 years old, and understanding the interactions between the normal gears and chains is already quite challenging for this group, so my current focus is not on adding more elements. But like I said: I'd love to see others working on it and would be available to help.
I'm surprised this one uses canvas instead of SVG, actually. Compatibility reasons?
I was a museum gaurd at an art museum that had his work last century. He now has a permanent home at the MIT Museum.
Am I the only one getting this? Chrome 28; Windows 7.