CarBEN EV5 Full Sized Prototype Construction - 5 Seat Electric Car From Scratch

[NeilBlanchard]

I'm hoping that CarBEN EV5 will weigh under a ton, so your guesstimate is hopefully close to how it turns out.

I'm feeling better about the Saab 900 front suspension and the Porsche 914 rear suspension. I thin they will work well enough to test the aerodynamics and the practicality and the range of this prototype.

The other reason I can't use the 2CV suspension is the front and rear wheel tracks are the same width - CarBEN EV5 has a rear track that is 7" narrower than the front. And a big battery pack like I hope to install (50-55kWh) in CarBEN has to be in the floor, because the weight of the battery will be almost half of the total weight of the car - and that means it has to be in the floor. And it has to be between the front and the back wheels.

I'm actually working for pay this week (at an architect's office), and I'll be buying some fiberglass and the windshield soon. I also will be stopping by my local Saab dealership to see if they have a 900 I can look at. Does anybody know if the 900 has equal length driveshafts? It might even be possible to use the differential from the 900, because the engine is longitudinal, if I am not mistaken.

[California98Civic]

Originally Posted by NeilBlanchard

Does anybody know if the 900 has equal length driveshafts?

Here are some guys talking around this issue, though mostly comparing auto and manual trans shafts. Hope it helps.
http://www.saabcentral.com/forums/sh...ad.php?t=93820

[Daox]

Wow, 50 kWh, mr deep pockets.

[NeilBlanchard]

Yes, the battery in particular and the drivetrain will be the big ticket items! I'm planning on doing a crowd funding campaign (i.e. IdieGoGo or Kickstarter) to pay for these, at least.

From my blog (in case you've missed it):

CarBEN EV5 Open Source Project Goals

*Open Source means shared ideas and shared improvements – anybody can build one. Creative Commons (instead of Patents) gives attribution but lets ideas get used as much as possible.

*Build working Prototype to test efficiency and improve construction methods

*Practical and safe and highest efficiency possible using renewable energy

*300-400 Miles Range on Single Charge using ~55kWh lithium battery, <150Wh/m, >224MPGe

*Coefficient of Drag (Cd) <0.15 with 25.1 sq. ft. frontal area = CdA <3.77 sq. ft. (better than GM EV1)

Design Innovations & Key Features of CarBEN EV5

*Tapered Shape required for low drag w/ narrowed rear wheel track, covered wheels, smooth underside, crisp trailing edges aka Kamm back, wheel strakes, passive air flow through cabin

*Thermal insulation integral to chassis and dual layer windows, heated vests for passengers, slim ergonomic seats allow for air flow saving space and weight

*Center Position for driver for increased crash protection and better use of interior space, three ~6'-4”+ people, one ~5'-8” person, one ~5'-0” person

*All LED lighting, ideal ecodriving design, battery pack in floor for low Cg and better handling

*Side Video Mirrors for reduced frontal area and lowered Cd

[freebeard]

It might even be possible to use the differential from the 900, because the engine is longitudinal, if I am not mistaken.

Frayed knot.

Originally Posted by Wikipedia

First, the engine was installed "backwards", with power delivered from the crank at the front of the car. Second, the transmission, technically a transaxle, bolted directly to the bottom of the engine to form the oil pan (albeit with separate oil lubrication). Thus, power from the crank would be delivered out of the engine at the front, then transferred down and back to the transmission below, via a set of chain-driven primary gears.

I'm feeling better about the Saab 900 front suspension and the Porsche 914 rear suspension.

"The Saab Museum--an independent history of the Saab marque
Saab Classic 900 Technical Specifications
Body: Combi Coupe, five doors, five seats, 1,174kg/2,583 lbs."

Wikipedia.org/wiki/Porsche_914: "Curb weight 940 kg (2,100 lb)−995 kg (2,190 lb)"

So the SAAB is +500lb and the 914 is -3 passengers

The other reason I can't use the 2CV suspension is the front and rear wheel tracks are the same width - CarBEN EV5 has a rear track that is 7" narrower than the front.

You've got a point there. (see my Profile picture )

...heated vests for passengers...

Not the seats? Will the vests be hard-wired or powered inductively? How about radiant heaters in the dashboard/seat backs?

*Open Source means shared ideas and shared improvements – anybody can build one. Creative Commons (instead of Patents) gives attribution but lets ideas get used as much as possible.

How much do you know about Open Source? I want to use it; not so much so that the ideas get widely used—I want to protect those ideas from predatory capitalists.

[NeilBlanchard]

I'm using Creative Commons, which is essentially like copyright, but the only stipulation is attribution. Open source means that anything that you learn is shared with others.

Here is the Creative Commons website: Creative Commons

I'm planning on the heated vests being plugged in after folks sit down. You can buy these for $75-100+ and they are not carried around in the car all the time, even when they are not needed.

[freebeard]

I get the basics. Closer to what I'm thinking of is Opensource Architecture - Wikipedia, the free encyclopedia, a space occupied by Open Architecture Network

What I don't get is this: I don't expect society to be ready for some particular housing designs until after something breaks the status quo. I also don't expect to be around forever. So what mechanism insures that the License isn't abused if I'm not there obsessively scanning the world for evidence of infringement.

I should probably just go to Open Architecture Network with the question; I'm not much of a joiner, it was a big step for me to register here.

[NeilBlanchard]

I still might be able to put the electric motor in place of the transmission. Although, it would be better to avoid the 90 degree change in direction in the drivetrain, I think.

The way I look at it, a good idea can't be contained, even if you try. If someone makes money with your idea, then your idea does some good for more people than if only you make money with it. Creative Commons is about attribution, and open source is about collaboration. A good idea that is bottled up is not very useful.

[freebeard]

Here's my benchmark for drivetrain packaging:

The claim is motor, gear reduction and differential in the form factor of a Porsche 901 transaxle. With Porsche-level power. I think I found that at Autospeed.

The way I look at it, a good idea can't be contained, even if you try.... A good idea that is bottled up is not very useful.

I see examples of ideas suppressed because they might inhibit established players in the market. I like CC because it uses copyright law to simulate anarchy.

[cRiPpLe_rOoStEr]

That drive setup looks good, altough regarding electric drive I'd rather try some hub-motors if I were doing a similar project.