CarBEN Model -- 1/24th scale model and 3D computer model for EV

[todayican]

Niel, I think a lot of the engineering hardnesses can be avoided with some "assimilation" when it comes to the chassis, you might even be able to tap a market even if people arent in love with the shape :-)

being a fairly tall 5 seater EV, Im guessing overall weight once finished, will be 2000 lbs at a minimum. A tried and true replacement front suspension the hot rodders use might be just the ticket for you:

CUSTOM 1932 FORD IFS FRONT END 32 mustang 2 suspension - eBay (item 290513369341 end time Dec-23-10 17:08:56 PST)

Its a "bolt in affair" and likely to alleviate a whole lot of design headaches.

simalarly, if your going rear drive, a shortened toyota rear on leaf sperings or even a gm might be simple and sturdy (EVs, even lower powered ones can really pack a punch on a diff)

The thing that might be of interest to the market is in you building a "skateboard" GM has been talking about it a while now, where the chassis, batteries, and most of the drive components are in the "bottom 11" of the car. people could build whatever they want in the way of the body (The easy part) Want a pickup, just put on the pickup body, etc..

[todayican]

DOH, happens every time I only read part of a post thread, Ya the eco move "Skateboard" Im curious, if someone were to build one, rolling driving wheels and all, the end user would simply install their body, what would the marketplace pay for one (Assuming there was 12k of actual materials in it) like an ac-50 motor, 10kw of batts etc?

[NeilBlanchard]

If you take the Edison2 VLC 4 seat chassis, without it's engine, it weighs about 730 pounds. The 54kWh pack I'm showing (768 EiG cells) should weigh about 900 pounds, and the electric motors and controls another 250 or so? About 1,900 total?

Weight is not super critical -- the Illuminati Seven weighs ~3,100 and it goes 200 miles on just ~32kWh. The FVT eVaro goes 120-150 on it's 21kWh pack. You can regain the energy from weight two ways: coasting, and regenerative braking.

Aerodynamics are most important for good range. Aero drag is a total loss -- there is no way to regain it. So, the aerodynamics of the CarBEN are the most critical to me. I'm hoping to be less than Cd 0.15; and maybe even as low as 0.12. The frontal area is about 25 sq ft, and because it is more or less square in section, that frontal area yields a lot of usable interior volume. It is not a whole lot bigger than a Smart, and it fits 5 people instead of 2. Here's an older version of CarBEN compared t o a Smart.



I am now using the Smart's windshield in the CarBEN.

[Frank Lee]

Originally Posted by NeilBlanchard

The driver's head position is related to the upright seating, and the motion of the driver's head in a crash will be a radius that misses the windshield. I will likely put an 'X' harness with a lap belt.

Driver's head will still hit, guaranteed, even if only for ingress/egress.

I was at a car show once and sat in some special bodied Shelby convertible. The top of the windshield frame was too close to my face for comfort. It was obviously one of those things that looks good on paper (or CAD) but didn't translate to real life the best.

Occupants need some wiggle room. I remember flying C-150s in the winter... the instructor (a slender female) and I had to take our jackets off before getting in so that we could shut the doors and function once inside! Put 5 claustrophobes in that thing and they'll bust the doors off trying to get out.

Even Microbus pilots don't sit that close to the windshield.

[NeilBlanchard]

I agree Frank -- a full size shell mock up will be the only real test. The leg room has lots of wiggle room, and originally, I had a custom windshield that had more room in the center.

[Frank Lee]

I didn't mean a full-size mockup of this had to be built from scratch; I meant you could simulate your interior dimensions and constraints in an existing vehicle.

[NeilBlanchard]

The horizontal space between the driver's forehead and the windshield is about 10". This is closer than in my Scion xA, but not a whole lot -- I'll measure it soon.

[todayican]

Neil, this might sound weird, but the guy in the drawing looks anatomical, true enough, but seems to be "bolt upright" any slouching or squinting as in "what does that exit sign say"? and ya, it might be close.

[NeilBlanchard]

Here's the 1:12 model in process:




By way of explanation, the three sections that are closer than 1" apart are the front and rear axle centers, and the high point of the roof.

[NeilBlanchard]