Build a car from scratch....

[CobraBall]

Bomber,

This is a free modeling software site. blender.org - Features

Requires 2gig of memory.

The price is right but it may be complex.

[IndyIan]

Maybe kevlar is a better value than carbon fibre?, our canoe seems pretty tough anyways!
My big idea is a 2 person inline tricycle. Using an aluminum(or fibreglass) canoe upside down as the body and chassis. A long low glassed in cockpit, some out rigger faired wheels out front, maybe just a motorbike engine and transmission in the back and away you go. $2500 in materials and maybe 100mpg at 80mph?
Maybe see if you can design something like that before you go for the ultimately engineered electric car? Less exciting I guess but it would still be a challenge to get right.
Ian

[Funny]

I look forward to the progress of this build. I was wondering, have you priced out the in-the-hub motors? I am just wondering because those would be excellent to make a rear wheel electric, front wheel gas vehicle .

[Blue Bomber Man]

Kevlar is a good composite to use with carbon fiber, but without it I do not think it has the right properties for a vehicle. Kevlar provides excellent resistance to punctures and tears but the carbon provides much more support

I probably will use both together for their combined properties.

[Blue Bomber Man]

I do not have a price yet, but I am sure they are pricy, but in large numbers for a manufacture they may be comparable to what they replace in a conventional car.

Once I get further along in my plans I will try to contact them and see if I can convince them to either sell some to me for my project (they normally will not sell to individuals) or if I am lucky enough, have them sponser the project and provide the wheel hub.

[CobraBall]

Kevlar has poor UV resistance qualities and looses strength twice as quickly in sunlight as polyester.

Kevlar should be coated with another UV resistant substance to prevent it from breaking down.

[trebuchet03]

Blue Bomber Man, if I may offer a bit of information regarding software...

There are a few big suites major engineering/design firms use.

*SolidWorks
*Pro/Engineer (Wildfire)
*Catia
*I-DEAS

There are others, these are the major one's I can recall off the top of my head. I have used all of them except for Catia. All of these function for parametric design - features are saved as steps, not verticies.

I personally favor solidworks for it's easy integration with both CFD (Floworks) and FEA (Cosmos). {I own a snazzy Solidworks backpack too } But, I don't know what's missing from the student license... I highly recommend that you get in touch with me VIA email

For designing a car, something rather complicated with >15,000 parts - any one of these pieces of software will do. But that doesn't mean you can't use something else. BUT - when designing bottom up, can you afford to do so without FEM analysis? My opinion is absolutely not - especially if you're using composites. That doesn't mean you can't build something that works without the analysis, but safety is a legitimate concern.

Coraball is right, Kevlar does lose some of it's properties when exposed to UV.... If you use it, use it under your other composite materials (or between). Kevlar is NOT sandable, just FYI (it will ball up and create a nightmarish mess).

I think your budget of $15,000 is a bit low. Unless this is a tiny car. Don't underestimate the cost of the hundreds/thousands of fasteners necessary to assemble http://www.grabercars.com/ - this is a beautifully made car from scratch (now sold as a kit less drive train for $25,000 - I imagine the first one off is more than that).


Don't get me wrong - I'm not trying to discourage you. I would just hate to see an awesome project like this backfire after a dead end.

But again, eMail me

[i_am_socket]

Blender is great for rendering images (I've used it quite a bit for this) and even game modeling and animation, but it's not designed for engineering.

[Blue Bomber Man]

So I finally have a legitimate reason to bump this back up. Today I finally obtained a copy of Solidworks 2007 with no limitations attached to it! So now I have the joy of learning how this beautiful program works. Once I get into it more I will probably need to invest in a desktop that can handle the demands of CFD analysis.

I also need to find a powerful website designer program, I hear that Dreamweaver is well recommended. Can anyone offer some insight on this?

Thanks for any help!

[The Atomic Ass]

Originally Posted by Blue Bomber Man

I need to learn more about the life cycle of the batteries based on charge cycles. One battery was quoted at 300 cycles, which seems low if that means I could only charge it 300 times total before having significant losses (20%)

Allow me to help you a little on that. Most of these life cycle numbers are based off of 80% or 100% DOD through ALL the cycles. Meaning if the cell is rated for 300 cycles at 100% DOD, it will endure many more cycles if those cycles never go below 80% DOD, and the gains in cycle life get disproportionate as you lower your average Depth Of Discharge.

Get a chart of the battery you're looking at, and see how it looks. If you over-capacity your pack, (say, to where a normal driving day with opportunity charging keeps you below 20% DOD), you divorce yourself from cycle life for practical purposes, and have to start factoring in chronological life. (Which is as yet very much a mystery with Lithium batteries.)

Personally, I'm researching the Zebra battery. Although it's horrendously expensive at the moment, there is very little in the way of information on life characteristics, and they have a high-self discharge due to the heaters, the energy density they promise leaves Lithium spitting out dust.

If enough solar can be added to my design to compensate for the heater requirements of the Zebra battery year-round, I'll be going with that over Lithium.

Also, while you've got access to that program, would you care to share your work output and/or do some designs for a small amount of compensation?