EV conversion using wheel motors

I’m in 2nd year of “gymnase” (highschool equivalent I think) in Switzerland, so I have to make a personal project. I’m planning on converting my own EV, but I need a little help…
Basically, rather than doing the usual motor replacement, I’ll be using in-wheel (hub) motors (2 of them), simply because I won’t need a gearbox, transmission etc, which means less energy loss, and less weight (in my wallet too ^^), plus I can use the freed space for the batteries, rather than waste trunk space.
So far I’ve found (the only?) three wheel motors manufacturers…
[li]PML : they make a very powerful motor (the hi-pa drive), and have made their own conversion to showcase it. It’s actually a hybrid (with a go-cart engine used as a generator). It’s a 4-wheel drive mini, does 0-100kph in 4.5s, has a top speed of 240kph, and over 640bhp. Problem is, the motors haven’t entered production yet, so they cost £9k apiece, plus £4k for a 2-wheel controller…Let’s say it’s a little over budget :wink:
[/li][li]TM4 also make “just” one motor, and have no real pictures or applications, so I suppose they haven’t entered production either…But the big advantage of these is the mechanical brakes (which are the minimum requirement if I hope to make the car street-legal)
[/li][li]the last one I found is e-traction. Their “TheWheel” looks very promising, and they’ve already made quite a few EVs (not hybrids) with them (plus they’re based in Europe, so that means less shipping fees if I get those).

Anywho, does anyone know anything about these (or just wheelmotors in general)?
And what kind of batteries would be best? I won’t have an infinite budget, but I still need something efficient, as I’ll often be doing 200+km trips (or just 100, if I can charge the car over there)… I was thinking of Li-Ion, or maybe even that new ultracapacitor battery that’s supposedly going to be 10 times as efficient as lead-acid, at half the cost. It should be out sometime before the end of the year I think (though I can’t find much detailed info)

Thanks in advance,

If you’re not wealthy, this stuff will be beyond your means (and mine :mad: ) for at least 2 more years. Sorry.

aha, but that’s where the “16 year old’s high school project” aspect comes in… it will (well, it should, anyway) make it easier to find sponsors…plus a big car means more ad space in case I run out of funds :wink:

Well, if anyone is interested in my project, I’ve finished my blog where I’ll be posting updates (there’s just about nothing there yet - check back later) here
You could also have a look at my thread on the DIY electric car forums

Craig, An idea for you. Check patents for Siemens or Ferdinand Porche from around 1898. If I am not mistaken they had invented a “wheel motor” then. Might be an interesting co-operative project with other machine shop students and also science club to construct your own motors. Who knows maybe a NEW GREEN car company might emerge! - Foxtrot70

The in-wheel motors are still very expensive [read - they aren’t really that expensive to produce, but oil companies/interests still have a major share of the companies/technology that currently make them], that’s if they are even available to mere mortals. Li-Ion batteries are also still quite expensive, though more available so it should be easier to find sponsorship/donation for those.

A more affordable solution, which I started thinking of about a year ago, is using in-board motors hooked directly to CV half-shafts.
The multiple motors (48-72V?) could be smaller than what is necessary for a single motor and shouldn’t take up much more room than standard axle/diff drive components. This would cost more than going the single motor route, but wouldn’t be as expensive as hub motors. I would think these could be whatever a single motor spec would be for the vehicle in question divided by two for driving two wheels or four for four wheels.
This would be ideal for making an AWD vehicle as each wheel could be controlled independently (think super traction control) and wouldn’t have the compromises that are made with axle differentials (open, LSD, locking). Plus I think with AC motors and regen it would make for a pretty effective braking.
This type of system would need some type of central controller, which I would think could be rather simple if independent motor controllers are used. My thought is to use a linux-based central computer that handles several functions, one of which is the interface with the multiple controllers. I can certainly handle the computer side of things - programming, OS setup, etc. but I’m not so knowledgeable with the hardware side.
I have a Mitsubishi Eclipse Spyder that I plan on converting (previous owner had a piston rod try to escape the engine block and I’ve started removing the ICE components since I got it), and probably my '59 Mercedes at some point also.

I would like to use the Spyder as a test bed for this, but without some funding or sponsorship I’m thinking I will end up going the old single DC motor route as funds allow and work on developing a central computer for system monitoring, optimization, logging, etc. which could be adapted to an AWD system later.