A few detailed suggestions for challenges from a dedicated fangreenspun.com : LUSENET : Junkyard Wars : One Thread
Here are a few ideas I've been thinking about since becoming a fan of the show. I've done some checking, so I'm pretty sure none of these has actually been done. I'm including lots of detail, and I've also made an effort to focus these on particular engineering challenges, instead of just "big machines that bash each other, huh huh, huh huh huh, cool."
1. TARGET SHOOTER. The contest presents a time limit, and a series of targets to be knocked down. Specifically, I envision a high wall, like a three-floor apartment building, with carnival/midway-style targets in the windows. The teams must construct devices to knock the targets out of the windows. To increase the difficulty (thereby making it worth considering for the show), the challenge should emphasize accuracy: The targets are worth points, and some of the targets actually *deduct* points if knocked out. In other words, the team couldn't just make a firehose and spray the whole wall down, because they'd lose as many points as they earned. As far as approaches to the challenge, the teams could make slingshots, or air cannons, or water blasters; the possibilities are vast and varied.
2. CAR WASH. Just what it sounds like. Each team, in the competition, is presented with three vehicles, caked with mud, grime, or whatever. For added difficulty, you could have three different-sized vehicles -- a passenger car, a pickup, and a van (lorry). Or, alternately, you have three identical cars, but they're dirty in different ways: mud, then grease, then, oh, say, plaster. The objective measure of success would be to paint a grid on the vehicles; the winner gets the most squares clean. (Just to be goofy, instead of three vehicles, they could be given a school bus to wash.) The devices must be mechanical, like the grass-mowing machines; no scrubbing by hand. Two alternate approaches: high-pressure jets, and mechanical scrubbers, e.g. big rotating brushes. The fun comes from a big frame, whirling things, and spraying water making the teams soaking wet. (If you wanted to guarantee high ratings, one of the teams could be Hooters girls in thin white t-shirts.
3. FREEZER. The challenge is to produce as many ice cubes as possible with a time limit. This would be similar to the windmill challenge they did in Season 3, in that the devices they built were for capturing wind, but the competition was measured by quantity of coffee beans ground. Similarly, each team must create a device that can supercool a chamber, and the competition is judged by how many ice cubes each can produce in, say, two hours. Initially, I had thought about making the competition simply to cool a jar of liquid to a certain temperature, but that doesn't make very exciting television, as the team puts a jar in a box and then sits and waits. (If anyone has better ideas on how a freezer could be judged objectively in a visually interesting way, I'm all ears.) Two alternate approaches: One team creates a standard compressor/expansion valve design, say with ammonia, like a regular household freezer; the other sets up a smaller, less efficient chamber using the same principle but then achieves additional cooling thermoelectrically (the Peltier Effect).
4. LOUDSPEAKER. A simple challenge: Using a supplied sound-reproduction device (e.g. a Walkman and cassette), build a device that broadcasts its audio at the highest possible decibel level. There are lots of different variations on how to make speakers.
OTHER SILLY IDEAS I HAVEN'T WORKED OUT IN SUCH DETAIL
1. MILKING MACHINE. Give each team a cow (yes, a cow: moo, and all that) with a "ripe" udder. The machine that first pumps out a pint (quart, gallon, whatever) wins.
2. PRINTING PRESS. Churns out pages. Pretty straightforward. They could have a flat press (like Gutenberg's) or try for a more complicated drum arrangement.
3. TOASTER. Yes, for toasting bread. To make it big and goofy, the challenge would be to make as much toast as possible, so they'd want to make machines that can toast like a hundred slices at a time.
4. CHAIN SAW. This would be pretty dangerous, but they've done some pretty chancy stuff already. Anyway, just build a machine that cuts through as many logs as possible in a time frame, or, alternatively, be the first to chew through ten.
5. STUMP PULLER. Self-explanatory.
Anyway, that's just a few ideas. Obviously, I really LOVE the show!
-- Cervaise (firstname.lastname@example.org), January 03, 2001