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The inner teeth are there because I used the gear tool as a shortcut to make a ring. Ignore that. And the red wheels do turn, but only when the the inner and outer rings are spinning at different speeds.

I'll edit.
The Computer Is A Cheating Bastard. The computer "person" is at least twice as fast as you are. I would scale the scene up so the ball falls slower, and make the computer the same speed as you are.
@Physicsguy (and anyone else for whom it doesn't work):

This scene is not only Phun-compatible, it is Phun-only. Evidently there are slight differences in how Algodoo solves friction, collisions, hinges etc. so mechanisms go off prematurely in Algodoo. It works fine in Phun, however.

And it's a seriously awesome Rube Goldberg, so it's worth your time to redownload and open in Phun.
I made it. It was actually really easy—everything is sequenced such that it only becomes dangerous after you've just past it. There are a lot of close calls but very few genuine dangers.

That said, awesome scene.
Not really realistic—your trebs have a mass ratio (CW/ammo) of 4000:1. The most ridiculous treb around today (Yankee Siege, current pumpkin-throw world-record holder, can throw 100lbs 2000ft) has an MR of only like 600:1—and that record was set at half or a quarter of that. If you allow an MR as absurdly high as yours, then yes, breaking the arm up will allow a treb of a given bounding-box size to throw further. A realistic treb will already be running at near-maximum efficiency.

I built a treb a while back that can throw the same 5kg farther than your supertreb with only 400kg of CW (MR of only 80:1)—and I suspect could throw somewhat farther with a little tuning.

http://www.algodoo.com/algobox/details.php?id=34461
Last edited at 2010/06/22 20:09:52 by daniels220
I'm not so impressed by the throw speed—you have an MR of 16k:1, of course it can throw really hard. What is pretty cool is that it steps down its throw speed almost linearly, with very little change in angle, down to a CW of only 500kg, which is a much more reasonable (though still extremely high) MR. It's still not as efficient as my FAKA, but that's because a FAKA is theoretically about the most efficient design known. The only more efficient design, in terms of MR, is a one-of-a-kind treb called Merlin, which I can't build in Algodoo because it uses curved load-bearing surfaces.

http://supertrebs.com/Merlin.html

BTW, feel free to take the basic FAKA design and see if you can tune it for high-MR throwing. Maybe add another section of arm, maybe just mess with the lengths... I bet you could get a supersonic throw with only a few-hundred–to–one MR.
Actually, I misremembered. I have a Merlin with a one-piece track that doesn't mess up, it just kinda sucks for some reason. There's no real whip at the end and tons of energy left in the CW. Here:

http://www.algodoo.com/algobox/details.php?id=43520

The challenge, I think, is in the tuning—as the forces involved get larger the track may become an issue, but right now it's more that I'm horrible at tuning.
(You can make the CW a super-high-density box instead of the unwieldy baskets—I was working under a single-body weight restriction of 100kg.)

@s_noonan—never bothered to calculate the efficiency. Neat to know. Certainly the FAKA rattles around a lot, so it's nowhere near 100% (or even whatever the theoretical max is for the FAKA design). A perfectly tuned FAT, in particular, will have the counterweight come to a dead stop with no rebound when it lets go of the shot, while FAKAs are known for crashing around and derailing if not PERFECTLY tuned. Mine's not bad, but could be better.
It's stable at unreasonably high speeds, but produces very little actual power. I built one that's stable up to 6k rad/sec (balancing is key), but it only takes a 100Nm motor to stop it. Since I don't think it's possible to build a transmission that can step down speeds that high, it's hard for me to see a use for this. It is pretty cool though.

So, a challenge: can anyone get one of these to produce, say, at least 200Nm of power at <6kRPM (not 6k rad/sec, which is more like 60k or 600k RPM, not sure which)?
With InertiaMultiplier it's possible to create a car with an arbitrarily high top speed and infinite acceleration. Box with +inf IM, hinge a circle to it, give the circle +inf friction, give the hinge whatever speed you like and +inf strength. "Fastest" anything is pretty pointless in Algodoo/Phun, since all materials have infinite strength (boxes cannot shatter or bend) and the physics stays the same at all speeds (rather than nonlinear high speed effects being visible).
Whoops, ignore this. Why doesn't Algobox have a "delete comment" function?
Last edited at 2010/09/22 01:23:06 by daniels220
That is seriously awesome. It does get stuck in tight corners however—really it needs much more complex logic directing it. I made a stab at it with a second set of LR lasers aimed much further out that force a sharper turn, and setting the "back up" laser to trail off slowly, so it backs up a lot before trying again. That didn't work that well—it was much more erratic and, though it got through areas it failed at before, it also failed at areas it had gotten through before.

An ideal guidance system would probably involve like 3 or 4 pairs of lasers in two depths, with actions assigned accordingly to each one. The simplicity of this system is amazing and encouraging, though—maybe I'll actually give a better one a shot.
Okay so first of all, I can't understand you.

And second, I can't understand WTF you did. How does making the outer circles spin affect how well the engine runs? Meanwhile putting extra weight to the outside does make it less powerful.

Please explain?
Last edited at 2010/09/23 16:41:49 by daniels220
Holy crap, you got the mechanism pretty much exactly right and it works great. You have my admiration for making Merlin work, which I was never able to do. Unfortunately in Algodoo KISS seems to be king—my FAKA, with 1/4 the moving parts, is about twice as efficient. But this Merlin probably beats everything else.
That really doesn't make any sense... The piano treb is just the basic type that's been around forever—it shouldn't be that efficient. But I dunno.
I recommend using light colliding boxes not lasers to change the airfriction—on slow computers lasers skip frames, collisions don't. The engines work but not very well as they are. If I increase the motor speed to make them more powerful, they die completely.
I noticed that it only works at 100Hz sim speed—I often leave mine set higher on non-laggy scenes and that seemed to cause it to fail. I don't know if that's the problem for you.
The principle of this motor is basically the same as any zero-length spring engine—springs mounted off-center on a circle, pulling on bodies hinged to that circle, almost always produce torque somehow. I'm not sure whether this one is any better than the most basic type—it's certainly a novel mechanism but, because it has more parts, may be more prone to exploding.