calbiterol

Yep. Pneumatics. Otherwise known as an air cannon. PVC, a spare bike tire nipple, and a bike tire pump, connected to a ball valve and something to launch the bearing. This setup gives you a lot more oomf than normal, for two reasons. First, the magnet doesn't have to overcome static friction, and two, the first bearing has added momentum to give to the next ball.

Cheapest way to get pseudo-ball bearings that work is to buy steel "slingshot ammunition." It's identical in every respect to ball bearings except precision (a lot less perfect of a sphere) and price (immensely cheaper). If you need to find something else, you're severely limited. It must be a paramagnetic material in the shape of a sphere.

To be honest, the easiest way to wrap nearly-perfect coils is with a power drill. For example, grip a nail with the drill, duct tape the end of the wire to the nail, and SLOWLY (that's the key this is where multispeed locking drills are amazing) wind the coil. Speed-wise, I don't know. I don't remember, however, if the design I put up here @ sci forums was the EM one or the halbach array one. Either way, it should work.

Just use a halbach array. I've used the principle behind a gauss rifle to develop (unfortunately, not create) an electric-powered paintball gun. The trick is getting the return mechanism right (and, in the case of paintball, the loading mechanism). Be extremely careful, because gauss rifles are incredibly powerful. 120 centimeters could, depending on the number of magnets used and the spacing between them, potentially kill someone.

You want blueprints for planes? That's going to be extremely hard to come by unless you're willing to fork out some cash (or so I would think, and my previous experiences would tend to agree). Good luck though. I'm looking at aerospace or astronautical myself.

Wouldn't this be more appropriate in engineering? Nanotechnology in its more mature form would manifest itself in microscopic robots able to both replicate themselves and (ultimately) manipulate atomic- and sub-atomic particles. Which has so many different applications. Currently, though, it's more of a materials type of thing - creating substances (like carbon nanotubes) with an organized lattice structure and superior physical qualities.

That's still aside from the point, though - I don't want to make one because of the economics of it, I want to make one (mostly) for the sake of making one.

There's plenty of problems that WIG planes are a solution for. Here's two, off the top of my head: airlifting massive tonnage and skimming about a meter above the ground or water. It's like a souped-up hovercraft in that respect.

Out of curiosity, how many of you are familiar with WIG (Wing-In-Ground) effect planes? For that matter, anybody here an aerospace engineer? Long story short, I'm thinking about building a WIG craft / hovercraft, and I was wondering if anybody had ideas for where to start out. I have hardly any idea where to begin with airfoil shape, body shape, etc - although I am familiar with the extremely basic principles of flight. Any good books on aerodynamics would be great too. As far as the maths in the books go, by the end of this year I'll be through with AP Calc BC (roughly a full year's worth of college/uni-level calculus, a bit shy of multivariable calculus), and I'm perfectly willing to learn more - and I teach myself quite well. Oh, and I'll also have completed AP Physics (I don't know if I'll be taking the B or the C test yet, but I hope to take the C, which would be roughly equivalent to a full year of college/uni-level introductory physics). I'm going to be building a wind tunnel first chance I get, too (possibly this weekend), and I've already built a hovercraft. It's currently being redesigned and rebuilt (something else I hope to finish this weekend). Any suggestions would be great, and thanks much.

Lots of money, too, for both of the above. Reading is cheap though, and the internet is free. JohnB, will do. We were actually there when I went, but it was almost a structured study-abroad program, so there was no leaving or anything. That, and it's over with. . But yeah, I'm planning on going back in a few years to go scuba diving on the Reef, among other things. Going into the outback would be a blast as well.

Grrgg. I miss Australia and NZ. We were there in the winter, and I still like it so much better than the States... You lucky little you, on summer break....

Thanks much. I'll try it out as soon as I get a spare moment or four.

Plus, there's a lot of people here who don't speak English as a native language, and spelling out your words completely makes it infinitely easier on the people who aren't as fluent with their English.

My wireless card is a Dell Wireless WLAN 1350 802.11g miniPCI card. The router is a D-Link Dl-524 (also 802.11g).

I'll throw up the details tomorrow. The router and card work fine when set up, I just don't know how to set them up in linux. Keep in mind that I've never actually used linux before this, so I'm pretty new at it (but I'll learn fast). Seeing as I'm typing this on the computer with the problems, yeah I can connect to the internet - I just can't get my wireless working on Ubuntu. It works fine in Windows, and I'm using 128-bit shared-key WEP encryption.

Hey all, and Merry Christmas. I spent the majority of Christmas Eve working on getting linux (specifically, Ubuntu 5.1) dual-booting happily with windows (well, that and wrapping, anyway). So far, so good, except one thing - I have not, for all I'm worth, been able to get my wireless LAN set up in ubuntu, or any linux for that matter (I tried it first with SUSE, which was brutal and didn't appeal to me, so I went back to Ubuntu, which I'd liked from the LiveCD). Can anyone help solve my wireless woes? Thanks much!

Merry Christmas! Or, as my atheist friend puts it, Happy LittleAtheistChildrenGetPresentsDay! Since all the well-wishes have been said, I second everything said above! Sad thing is, it's 2 in the morning here, and we're still wrapping presents. Heh heh heh.

Quick link before I go to bed that might be of some use: HowStuffWorks: Stirling Engines Page 3 might be especially useful.

I don't quite understand what you're asking when you say cylindrical, Thing. As far as the temp difference, it depends on the size of the chamber and the quality of construction, IIRC. Perhaps the surface area as well, but I'm stepping into the realm of speculation. The materials used (their heat conductance, for one) would also make a difference, I would think. If you can think of a way to make the bottom end of the flashlight the cooling portion, you'd be fine - I don't know how you even could hold the flashlight by the bottom, much less anyone who does.

I understand the desire to think "outside the bowl," but wouldn't the former be much easier? A simple pressure-proof, openable case can be easily made from PVC piping. That's actually an interesting idea - create a miniature submarine out of PVC. I might add that to my list of projects. Anyway, I didn't have time to read past the first two posts or so, so I have no idea if this has been explained or whatnot already. At any rate, thought I'd suggest it. Cheers!

I believe that's true, The Thing. I have not actually built one myself (it's on my to-do-ASAP list, I'd really like to experiment with them), but I've looked into their construction. I'm a bit of a perfectionist myself, so it would probably come (at least partially) naturally to me, but as far as I'm concerned, web plans give a good place to start, a general idea, but experimentation is, by far, the best teacher. As far as one or an array, I would start with one, just for ease of construction, but it wouldn't hurt to try both. As far as reliability goes, the array would probably be better (but keep in mind this would take up more space). Again, experiment. And by all means, have fun in the process!

A better way of doing it would be this: Have a very thin metal tube as the outside of the flashlight layer (and the thermal conductive layer for the stirling engine) and a pvc pipe as the inside layer. The space inbetween can be the heated chamber of the engine. You might be able to get by with only one stirling if you tweaked it right. Although from an engineering point of view, it would be better to have the smallest expansion chamber possible so that the expansion displaces as much as possible.

That was. Amazing. That too.

Thanks, I guess. Most of this information is relatively easy to find. Along those lines, google is your friend. Most of the above post I learned when I was around 12, because I was extremely interested in ballistics at the time, namely paintball guns and the like. But the boyish fascination with guns has never left me. It also helps that I love engineering and have a decent understanding of how guns work.

Yeah, that was all me brainstorming. Wouldn't have ever thought of it if Lance hadn't posed the question and The Thing mentioned body heat, but that's besides the point. As far as recharging at room temp - there'd have to be a core that was either warmer or colder than the surrounding area at all times. So, on second thought, that might not work so well, unless placed in direct sunlight. I forgot to mention that part. Since sunlight transfers heat, under the right circumstances something like this would recharge through solar power as well.