Hey, Sock, don’t get me wrong – all I’m saying is this sounds unlikely. But I’m perfectly willing to admit I could be proven wrong. What we need here is some sort of chart that compares all of these technologies. The first comparison would be cost-per-mile. A subcategory would be electricity used (averaged out on a per-mile basis) so one could directly compare compressed air-vs-CNG-vs-All Electric-vs-Fuel Cell. The second comparison would be pollution produced-per-mile. Here you get iffy, because you would have to average out general pollution produced by power plants in order to get a comparison of any sort against gasoline powered vehicles. The third comparison is one of convenience – how far can you go before “refueling”, and how hard is it to find a place to do so?
The howstuffworks site has several links and articles on air powered cars. so I’m reasonably certain it’s legit. As for the numbers I’ll have to hunt around a bit more.
Ponder, according to a book I’ve got on locomotives, at the time diesels began to surplant steam locomotives, diesels were slightly more expensive than steam locomotives to operate. However, diesels, electrics, and steam engines all came in around the same cost per mile (not counting the cost of the infrastructure for electrics), yet today, there’s very few steam locomotives in operation (interest has started to pick up in them, however). So, just because some thing’s expensive in the beginning, doesn’t mean that it’ll stay that way.
OMG, it’s time to go to bed. **Tuckerfan, ** I came into this thread wondering what on earth an air-powered CAT was.
[QUOTE]
*Originally posted by Tuckerfan *
**It’s not quite the same thing, but I imagine you could probably pick up a Davis fairly cheaply. I’ve thought about buying the plan.
Hijack-
I wanna site with plans that don’t require expensive or custom materials. I realize that isn’t workable when it comes to cars. But, why not a minisub from common items. The aquasub in the link has pontoons that remain on the surface. Air is drawn through a pipe from one pontoon to the cabin.
IANA engineer but it seems to me that plenty of bizarre bike designs can be made with parts of old bikes. If done properly the difference between the aluminum of old bike A and the aluminum of old bike B shouldn't cause too much trouble in the new frame.
I still dream of building myself a powered ultralite from junk. Only last week did I realise that my insistence on a trike frame was blinding me. Things become much cheaper and simpler if I use my legs on the ground. Why bother mounting the engine, propeller, and gas tank on the frame when I can simply mount them on my back? Leaving out the frame reduces the total weight and makes things simpler. Now, I just have to find a canopy/stunt parachute design I can build from junk. Anybody have any suggestions?[sub] I mean other than ‘stop! You’ll be killed!’ or ‘See a psychiatrist immediately’[/sub]
[QUOTE]
*Originally posted by DocCathode *
**
Doc, I don’t remember the name of the company, but there’s someone who advertises ultralight’s in the back of Popular Mechanics that has plans for something similar to what you’re talking about. This guy claims to have plans for an ultralight that can be built for less than a grand, and you can get most of the parts at Home Depot.
You forgot the fourth comparison: How long does it take to “refuel”? Electric cars take hours while a liquid fueled vehicle takes only minutes.
Hmmm…
Thanks, but I don’t think that’d be workable for me. For one thing, I live in an apartment. I don’t have space for a fixed wing craft or money for a hangar. Note that the last sentence says that glider cloth must be gotten somewhere else. There must be a way. I’ve got needles and thread. Maybe somebody will throw out a really, really big silk sheet and I can sew myself a chute.
The ultralite project has an approximate budget of $0. But I have time.
I wonder if a folding walker would be a suitable base for the backpack. It would need work to hold everything securely and be wearable. But folks sometimes throw out perfectly fine walkers.
I recently found a cite that explains how cast aluminum. Another cite explained how to machine a 2 stroke alumin engine. I've got an Uncle with a basement workshop. I'm sure he wouldn't condone my working with molten metal. But, once I have solid parts I'm sure he'll let me use the lathe, drill press etc.
There’s more but I really should stop hijacking this thread. I jsut don’t feel up to starting a “Help Doc Cathode with his harebrained and extremely dangerous project” thread.
Actually I would enjoy such a thread and I suspect Tuckerfan would as well.
Yup. 
Hehe.
I know a few ideas for compact designs that might be suitable for what Doc needs and if he decides to start that new thread I’m more than happy to go on and on about them untill even Tuckerfan says “ENOUGH”.
I wish I had the cite, but these compressed air cars and the one you mention in particular are not considered a really viable alternative. Performance was one big issue I remember, acceleration was piss poor and top speed sad. I will try and find more info, but you can also search the forum here, this topic (and that website) have come up before.
I just wouldn’t feel comfortable driving a car that looks like you could stop it with your feet.
With this car it seems to be a bit of both:
How long does the refilling of the tanks take?
In an air-refilling station, it takes between 3 and 4 minutes. At home, with a 220V plug, it takes 3 and a half hours.
I’m looking forward to attempting flight with a home made engine strapped to my back and nothing but a home made canopy to keep me in the sky.
But starting a thread about it is * really* scary
http://boards.straightdope.com/sdmb/showthread.php?threadid=194012