Street legal + Enclosed +Electric

[runcyclexcski]

Hi all,

I am researching on building a street legal, fully enclosed (i.e. aerodynamic), electric go-kart. I am currently in the UK. The street legal part is key, as I want to use it for commuting. I believe that with research, design and testing, a small cart could be made much safer, and more useful, than motorcycles and bicycles. Are there any existing prototypes that fit the legal/enclosed/electric description, and clubs I could join -- to avoid making mistakes and wasting time chasing dead-end paths?

My current line of thought for a prototype is like this:

(i) start with a robust, quality chassis designed to handle high speeds (e.g. a racing kart -- suggestions?)
(ii) install wheels of smallest known size to work on highways (classic Mini wheels are 10"?) -- has this been done?
(iii) add a roll cage
(iv) add a shell (tested in a wind tunnel at 100 mph side and front winds) -- anyone tried this?
(v) add a 10 kW motor (streamlining should help the small motor). I've used brushless outrunner motors before which were remarkably light for the power
(vi) assemble a battery pack from consumer LiPo units to give 10kW-h capacity. These now go for $20 for 50W-h (10 Ah at 5V), so 200 of these will do. Add a simple fire wall and have a capacity to replace a failed module
(vii) add street-legal features -- are there examples?

Are there any fundamental flaws in the above plan? I have access to a full shop, and I am a scientist/engineer by trade, so I can pull it through in 1-2 years working 1 day a week. Want to keep the weight under 200 kilos, even better if under 100.

 

[Kahrese lee]

https://youtu.be/a9d3wAjdknA

 

[DaRussian]

your obvious street legal features include the following
speedo
mile/km logger
rear view mirrors
indicator lights
headlights
emergency lights aka both indicators flash
ya fellas can add more if im missing something

 

[FreeRunner15]

Must pass emissions test, must pay for registration and tax fees, and seat belts too. oh and must have a windshield..Edit:and mirrors.

http://www.doityourself.com/stry/dune-buggy-3-laws-to-make-it-street-legal#b

Laws vary from state-to-state and country-to-country.

 

[mckutzy]

FR15.... howabout you listen to what people are saying...... he's in the UK....
That for the most part will help a bit....... but Electric vehicles around the world are ZERO EMISSION.......

 

[Denny]

Look for a newer electric golf cart it will do most of what you want (except the 100 mph thing). Tesla also builds a vehicle like you want, they been doing it for years.

Denny

 

[Toycrusher]

Most importantly, you need to decide what capabilities you need. How many passengers? What top speed? What range? In city only? On highway? Will a big rig be able to see you?

 

[itsid]

personally I'd start with one of the already street legal karts as a base..
(european laws allow for so called "micro-cars" and if we have them in germany, you will have them in the UK for sure )

That covers the Kreidler F100 / F170 go kart ..
no it's a petrol kart, but it already comes with a road legal registration and is the size you want;
so all you need to do is add the shell and convert to electric in a step by step process.

shells had been done numerous times in germany (no full enclosure though, it's a go kart thus tiny...) but I'm sure it could be done.
electric conversion is a bigger issue though.
first.. 10kW will not get you anywhere near 100mph!
twice that maybe (without doing the math)

Anyways, the concern is battery weight; batteries are heavy, and vehicles that size normally do not allow for huge additional weights, so you may end up with a lousy range (the more power the motor draws, the less range you'll get)

So just dial motor power and battery dimensions (weight/capacity and thus range) to your needs, not your wishes

'sid

 

[runcyclexcski]

Hi all,

Many thanks for the constructive comments and critique!

Regarding TESLA: we can all agree that their car is the current best known example. However, it's expensive (even though my project may end up costing in the long run as much as a new TESLA) and cannot be powered by sustainable sources (not considering options likes a nuclear power plant or a field farm to run it). So my idea is to make a nano=version of a TESLA which could actually be powered by solar/wind to be taken out once a week on long trips (200 miles). I think it's mathematically possible by:

- scaling down 5-10x in weight;
- making it narrower (1.5-2x), lower (1.5x), and more aerodynamic;
- making it a 1-person vehicle (most cars have only one passenger anyway), or a sit-behind version. Or if my girlfriend wants one, I will just make one more and we talk like pilots using microphones.
- I am fine with a top speed of 100 kmh at the moment (60 mph), acceleration of a regular commuter car is OK. I would not be ready to drive it on the highway (called motorways here), not the first p-type anyway, and on small roads in the UK you are not getting around fast anyway, in any kind of car.

So... I began by writing a script and downloading all of Tesla's existing 250 patents. Why not, if the knowledge is already there. Anyone wants a merged PDF?

Regarding the 10kW thing: Tesla S specs say 70 kW. Would one think that making a more aerodynamic car (resistance scales with a cube speed times drag factor) which is 5-10 x lighter bring down the power requirement to 10 kW? These are still ballpark figures. A 10 kW=h battery could be charged using solar and wind in 2-3 days at 200W input. And we have plenty of wind here in the UK.

Range: Ideally, Tesla-like, which is mainly why I downloaded their patents. If they did it, why can't anyone else? They claim they will start selling their packs to consumers for home use, at $400 per kW-h.

Street-legality things sound surprisingly easy!

Batteries: 50 kilos for a 10kW pack sounds reasonable, and I can compromise on other things and/or use fancy materials where I can. Moving from Lead-Acid to LiPO or LIFe cuts the battery weight 2x.

Being seen by trucks (called lorries here): I never understood the argument -- don't they see motorcyclists already (the latter, I would think, are more dangerous than an enclosed buggy). Then, bright LEDs can make it look like a christmas tree, daylight headlights.

I am a bit confused about dual motor vs single motor. I do not want to control two wheels with a controller, and get into a spin due to a software failure. Teslas are all-wheel drive, I believe. Are there good single-motor designs?



I will look into the F170 then! This video taken in Spain looks proper. Interestingly, the specs say 10 kW with top speed 88 kmh, so my back-of-the-envelope math is close to be correct...

https://www.youtube.com/watch?v=IX8T3Mtmu40

Specs (if this is the same kart...)
http://www.standardmoto.com/flo170.htm