An Archimedes Screw is just your regular screw-shaped auger/worm gear, used to lift water, corn, soybeans, etc., and in a lesser-common application by the Russians, was used as a propulsion technique for Siberian vehicles used to recover lost cosmonauts.
A racer is built using opposing twin screws that spin horizontally along the longitudinal axis of the vehicle, (ie, front to back), which propel the vehicle by literally screwing the entire vehicle along the ground like gigantic worm gears. These screws pull a chariot and charioteer situated behind them, a la Ben Hur / Phantom Menace, on a dirt track or maybe in a field. Winner take all.
<after po's comment> The screws would need to be powered by something torquey, like a farm tractor engine. And while I'm rather bored with resorting to conventional internal combustion, few workable options present themselves. Perhaps steam?-- RayfordSteele, May 21 2002 The screws might look something like these.. http://www.icechallenger.com/How to drive from the US to Russia... [RayfordSteele, May 21 2002, last modified Oct 21 2004] Kinetic Sculpture Racing http://www.avam.org/kinetic/Dr. Seuss goes to the races. [RayfordSteele, May 24 2002, last modified Oct 21 2004] the Screw Machine http://www.srl.org/...ix/images/px29.htmlSRL has them with blast jets [hello_c, May 24 2002, last modified Oct 21 2004] Marshall Screw Amphibian https://www.allpar....roving-grounds.htmlSee a little way down the page [RayfordSteele, Nov 01 2018] powered by? manhandled?-- po, May 21 2002 Steam would be good. But, given your link, isn't this just a suggestion to race things which already exist (even though there's only one of them)?-- angel, May 22 2002 Angel, sorta, but not quite. The only connection between this link and my idea is the screw drive principle. You wouldn't shoot down a weird car idea simply 'cause it has wheels, would you?-- RayfordSteele, May 23 2002 Certainly not, and I'm not shooting this down either. I rather like it in fact.-- angel, May 23 2002 Actually, his name is* Shoeless Joe Jackson... was* RIP-- thumbwax, May 23 2002 I'm picturing something that looks like a Star Wars pod racer.
Won't these just dig themselves into the ground? I don't see how the screws will propel them forward.-- waugsqueke, May 23 2002 The "screws" are cylindrical, not conical, and have their axes horizontal and parallel to the direction of travel.-- angel, May 23 2002 angel, yes I understand all that, but it still seems to me that the vehicle will sit in one spot while the screws just churn up the dirt.-- waugsqueke, May 23 2002 I can see how this would move if the surface was fairly hard. It would be one squirrelly ride though. The two (presumably counter rotating) screws will be trying to split the thing apart or compress it, depending on the directions they are turning. There would be a component of motion from side to side in addition to the desired forward motion. When the "traction" on one side is less than the other, the thing will want to move sideways.
Sounds kinda fun, but I suspect top speeds would be pretty low. Is the steering accomplished by a relative difference in speed between the screws?
I've got dibs on the earplug concession if you decide to race these beasts on asphalt or concrete.-- half, May 23 2002 Could you adjust the angle of the screw threads as a gearing system?
My gift is to take an unfeasible idea, then futher defease it.-- yamahito, May 23 2002 It would be one very, very slow race. Perhaps we could add a game of cricket to liven things up, since those games take days anyhow. Or alternatively, Archimedes Screw Chariot Polo.
The squirrelyness is half the fun. The other half might be simply getting the weight, torque, and speed right to build a moving vehicle. It would make for a great 'Junkyard Wars' challenge.
yam, as long as the threads are metric. ANSI has yet to devise a variable-pitch screw thread standard.-- RayfordSteele, May 23 2002 Wasn't it Archimedes who said
"Give me a place to screw, baby, and I'll move the Earth."-- stupop, May 23 2002 The screw system would make great designer lifts, too..-- yamahito, May 23 2002 Wait a sec. I guess you guys aren't seeing this the same way I am.
I'm not seeing how this device will move forward. I liken it to the image of Wile E. Coyote standing on skateboard to which he has mounted a sail, and he's pointing a fan at the sail. Not gonna move.
I can see how the vehicle itself will move forward relative to the screws, but the screws themselves are not gonna move forward.-- waugsqueke, May 23 2002 [waugs],here's the way I see it (for what that's worth):
The turning cylidrical screws, laying horizontally with the "thread" in contact with the ground would attempt to displace the surface (parallel to the axis of rotation) on which they are resting. The surface would provide an opposing force great enough to resist the attempt. Given the equal and opposite reaction thing, as long as the screw is prevented from moving sideways the screw would be moved forward.
A rough analogy is the way a propeller moves a boat through the water. The propeller is essentially a short section of a screw but with more than one helical "thread". (Aren't propellers on large ships and submarines referred to as screws?)
Only in this case, just the very edge of the propeller would be in contact with the water (dirt).
I'm sure someone will correct me if I'm wrong.-- half, May 23 2002 You're not wrong. The //opposing twin screws// will prevent it all rolling sideways.-- drew, May 23 2002 // I thought, from the title of this idea, that we'd become invaded by rather slanderous ancient historical graffiti. //
Perhaps I should change the title to 'Archimedes Screws Chariot Racers' just to add some mystery?
[drew], there will probably be some amount of side-slippage due to frictional differences, rocks, etc, but that's all part of the fun in attempting to control the thing.
[bzackey] see link for a "near tank"
// Having said that, this is going to be a fairly inefficient, uncomfortable method of propulsion. //
And thus the appeal of the sport. Perhaps this could turn into some form of kinetic sculpture race, where the goal isn't simply to cross the line first, but to cross the line in the most style.-- RayfordSteele, May 24 2002 [RayfordSteele]: Obviously it won't track straight as an arrow, but the twin screws mean it won't just roll off diagonally, which would be Bad. Make for a great cross-country ride - maybe on snow fields?
// kinetic sculpture race //
Wow.-- drew, May 24 2002 That would be a wide, grooved wheel then...-- drew, May 24 2002 random, halfbakery