Design Concept Beta

Based on the entry/exit concept discussed in my previous post, here’s a 3/4 front rendering of what that new, evolved shape might look like. Any thoughts?

11 thoughts on “Design Concept Beta”

  1. Yes, 2.0 is a huge improvement, kicks 1.0’s pedal-car ass. So it’s gonna open in two pieces? Door hinges out and canopy hinges over? That is a nice solution to the exiting-from-car-post-trauma issue, and easier to design than a window-encompasing door, and combined with your higher-than-a-non-tilter seating position should make getting in/out pretty comfortable, seems like a lot of benefits from simple solutions. Are you thinking about cabin airflow yet? I’m planning to mostly use forced air for ventilation, w/ these small cabins we can use 12v computer fans – say two in the front & two out the back – would easily refresh the cabin air every 20-30 seconds w/o much draw on the battery. Going compound curves means sculpting foam, and LOTs of sanding and filling, the step that kills most projects like this (RQ Riley’s Trimagnum – 40,000 plans sold, less than 20 finished cars on the road, regular trickle of unfinished Trimags on craigslist & ebay always rollers w/ unfinished bodies) – are you up for 100s of hours (some Trimag builders report 1000 or more) of shaping & filling?

  2. Yeah, I’m comfortable with the time investment. I did a LOT of model building as a kid, so lots of hours spent on meticulous detail is something that appeals to me actually.

    I’m glad you like the aesthetic! The biggest thing for me is getting the entry figured out. Having the canopy open to the side opposite the door should really open it up nicely.

    I’ve thought a bit about internal environmentals, but haven’t planned them out in any detail yet. The canopy is going to mandate some sort of artificial airflow system if for nothing but keeping it from fogging. But I think I can do better than that. I plan to install a small heat exchanger to grab heat off the cooling system and give essentially car-style heat for cold days. I’ve also thought about a thermocouple setup as basic, electric air conditioning. Lots of options, but nothing finalized yet. Bottom line is that if there’s going to be a lid on it, there will have to be some basic climate control.

  3. Cool, as long as you don’t mind the time investment, it’s turning out to be a very pretty shape. Coolorheat.com sells car seat covers that use little piezzo-electric radiators to cool & heat water from 60-98 degrees, that’d be the simplist off-the-shelf solution, there’s really very little market support for heating/cooling (especially cooling) really small cabins (unless you don’t mind packing ice on hot days). Oh, and plan a little space in the nose for an air-box, something that bugs & debri can enter and then smack against a wall before being directed into the cabin.

  4. Ooh! Looks like all it’s doing is exchanging heat and pumping water. Hook a couple of those up in tandem and have them circulate water through an air exchanger. That’d be pretty slick. I imagine that heat exchanger is probably sourceable if we scrounged around a bit.

  5. these sit-on units are pretty slow, taking 20 minutes to get to a noticeable hot or cool temp, and draw 30w, which is impressively low but the stock Burg400 can handle about 100w of accessories, so even at max running 3 inline you’d have to change your expectations of what heat/A/C were. The Prius uses an electric compressor to run more efficient A/C, hopefully similar systems will start showing up in all the new citycars we’re supposed to see any year now. Hard to beat old-tech A/C systems for a quick blast of really cold air, it’s the climate-control equivalent of revving the engine, good for the cars libido. Just small cabins don’t need a lot of a/c and hooking up any existing system is expensive and inefficient – a mass-produced small cabin electric system sure would be nice.

  6. One of the biggest things you can do to help out with the AC need of an enclosed cabin like this is to ventilate it while parked. The Aptera uses roof mounted solar panels to power what amounts to a couple of computer cooling fans to keep fresh air circulating into the cabin when the sun is shining (which is the only time you need it). That way when you get in the vehicle, it’s at most a few degrees warmer than the outside, instead of 100+ degrees on an otherwise reasonable (75-85) day. Automobile AC units are oversized for exactly this reason. They need to cool down the extremely hot cabin quickly and help soak all the heat out of the objects (seats, carpet, dash) to keep them from reheating the cabin again.

    I kind of think of it this way. If the vehicle never gets much hotter than it is outside to begin with, and I have a good breeze of fresh air while driving (like on a normal moped/motorcycle), would I need AC at all? I personally think the answer is “no”, but people who prefer to be closed off from the environment in their little cocoon of luxury would certainly disagree.

  7. PS. I like the new shape. Gotta love those old Ferraris, or the new ones. I have plenty of Ferrari love to go around. I’m not picky. 🙂

    Also, you can get a lot of visual appeal from paint scheme too, which is a lot easier than shaping. But do whatever you love. A little of both would go a long way.

  8. You make a great point about ventilation, Aaron. I’m familiar with that Aptera system and Toyota did the same thing in the latest generation of the Prius. I’ve thought about actually running two strips of solar panels down the top of the nose as racing stripes (or perhaps just embedding a few cells within stripes) for just that purpose. In good weather, I don’t want to have the canopy on at all. I love the open air experience of riding on two wheels and I don’t want to lose that on this vehicle. But the canopy serves great purposes for longer distance trips and for when it’s raining. It’s in the latter situation that I see some possible need (as opposed to want) of air conditioning. That is, some way to push cool, dry air across the inner surface of the canopy to combat fogging. There are more low-tech ways to keep the fog off, such as a soap film or other coating like is used on the face shield of my helmet. But if I could have a nice, cool cabin on a long, hot, cross-country ride, I think I’d definitely want it. The rest of the time I’d be going open top for sure.

    One idea I hadn’t mentioned is that of canopy stowage. Because of this new shape and how the canopy basically mirrors the shape of the tail, I could actually just stow it on mounting clips on top of the tail. That is, remove the canopy, spin it ’round 180º, and secure it on top of the tail. There wouldn’t be much of an aerodynamic loss, I don’t think, and that way I could always have the lid with me.

  9. I like your idea for canopy storage. The new shape was giving me ideas about popping up the rear and sliding it back to open up the cockpit. Then if you just wanted to improve your cabin airflow but not go totally topless you could just lift the rear a few inches and leave it in place (like a sun roof). Though I suppose you could do that anyway if you hinge it in front instead of on the side. I think your idea of reversing and securing it to the tail would be aerodynamically better than having a “sunroof/spoiler” effect when riding open air though.

    With all the thought about keeping the canopy inside fog free, have you decided how to keep the outside clear? Without a wiper your option is what, a lot of RainX?

    Also, have you found a source for that canopy? It looks like its going to have to be a cut down section from a glider canopy, or perhaps an Electrathon racer. Blue Sky Design sells Electrathon parts (including a canopy) for just that purpose, which they use themselves to build the BugE trike. They are at http://www.blueskydsn.com if I recall correctly.

    Aaron…

  10. I figured that I’ll probably use a single, small wiper up front and shape the canopy with enough of a flat area up front to allow a small, wiper-clearable area. Beyond that, yes, lots and lots of rain-X. As for producing the canopy, I doubt I’ll scavenge it, actually. I’ll probably build a plug for the shape and then work with some contacts I have who already produce lexan windshields and other things for scooters and motorcycles. Lexan isn’t actually THAT hard to work with, from what I understand. If you’ve got a nice smooth plug and a big enough oven, you can basically just slow form it. Although ideally, you’d want a big vacuum table. I’ll cross that bridge when I come to it. The canopy will likely be one of the more expensive components, that’s for sure. Thing is, I don’t have to have it in order to use the vehicle and I can create a tonneau cover for wet weather in the mean time. So the canopy can effectively be the last thing I do, so long as I build a dummy for all the attachment points. Worst case scenario, I can build it up from smaller pieces of lexan in frames and simply use pieces small enough to shape at home — a WWII P-38 kind of thing.

  11. Hi, I am thinking of building a similar vehicle myself and searching what’s out there I found your blog.
    I haven’t read everything yet, but it seems quite interesting and I will be following to see how it goes.
    I’m just starting the process, though, just starting to think if I could pull it off or not, researching a lot, etc, but anyway it’s fun and kinda reassuring to see you have come to very similar ideas about it all. I wasn’t that crazy after all! 🙂 Or maybe we both are. XD

    About the discussion in the previous comments, I just want to point out that a wiper over a lexan windshield will work fine only at the beginning and it will soon scratch the surface. I read this at the Moonbeam microcar’s website. (you probably have stumbled upon it too). For my own vehicle I was considering to use an old car’s safety glass (quite cheap) cut to size for the front of the windshield and using lexan for the rest of the windows to avoid this problem and keep weight to a minimum. I also have in mind that greenhouse canopy theme! not sure it would be a very aerodynamic solution, but would certainly look very cool! ( I love both messerschmitt Kr-200 microcar and Me-109 aircraft)

    Also, about the ventilation (if you haven’t already), you may want to check out the NACA ducts. They are a family of well defined profiles and shapes to channel air into a vehicle for cooling, etc., with minimal impact on its aerodynamics. Maybe you’ll still want an A/C unit in hot days, but the duct can be a good thing to have too.

    That’s it.
    So, cheers and keep up the good work! 🙂

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