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Tilting tadpole trike scratch build

14K views 12 replies 8 participants last post by  Cdog 
#1 ·
Hi all!

I must say im surprised i havent found this forum earlier.. would have saved me over $100 bucks for renting a web hotel to house my own forum, http://hordur.se

Well, nuff about that.. :)


First let me introduce myself and my project.. :)

Im a 28 year old CNC machinist who never owned a combustion engine in my whole life, with the itch of creativity always nagging in the back of my scull and a fierce rebellion against everything "normal" :)

I started dreaming about a leaning car after i saw a car show on the tv, fifth gear testing out the Carver and i fell in love!

A year or so passed and i stumbled uppon the peugeot liion concept car and my head blew off its socket!
My Johnson went haywire and my feet went numb every time i looked at the pictures.
This was almost a year ago.

But since nothing substansial happened to the liion car, and no others showed interest in a tilting electric car i decided to build my own.

The mechanical specs are pretty short so far; 3 wheeled tadpole (two front wheels) powered by a electric motor (the biggest allowed by swedish law, 15kw/100kg vehicle weight) and 2 seats in tandem.

Since im a plane-crazy SoB aswell, i wanted to make my vehicle look and feel somewhat like a fighter jet, with a sleak body and a clear canopy over the whole cockpit.



So the project isnt moving as fast as i would like, but im slowly getting ready to start fabricating (after months of cad studies, calculations and thinking).

Im going to build the body out of glass fibre with wood and foamsheets as sandwitch/insulation and bolt it onto a tube frame.
The bodywork is due start july 1st (first day of my holliday), and will be styrofoam blocks glued together and carved out to shape, covered in "plastic padding" and covered in glassfibre.

I will then use the newly made plug to create the molds in witch i build the vehicle from the outside and in, leaving the bottom for last (to ease fabrication and installation of all the bits and bobs).


Ive tryed to estimate the weight to be somewhere around 100-150kg without driver, meaning im limited to 15-22.5kW, but this should suffice for a everyday commuter vehicle with a bite :D



My to do list (rough):
Find a programmer familiar with AVR, ATMega or similar chip computers for tilt function aswell as user feedback (sensors, overload safety features and so on)

Finish the cad blueprint and send it to my partner in crime, my welder

Finish the outer and interiour design (is a VERY basic paper sketch as of yet)

Win the lottery to finance this beast of a project << most important!




This will be registered as a amateur build in sweden (aproved in most of europe as a one off product) but im investigating the possibilities to get a "factory permit" to be able to build and sell it as any other car manufacturer.

If the mass production idea fails, i will release the lot as blueprints/documentation free of charge under GNU licence or similar.
(Free to use and alter, but not for sale)


By the way, my doctor thinks i should get my head examined by a specialist and my woman thinks im simply nuts..
So im VERY happy to have found this forum where i can share my madness with my fellow nutjobs :D
 
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#3 ·
Welcome to the forums. Sounds like a great project. I have dreams of a tadpole scratch build trike in my post-lottery future also. Looking forward to seeing photos and CAD screenshots. I will be living vicariously through you.
 
#4 ·
I'm a big fan of leaning trikes, even started on a design for a leaning velomobile (goofy low res cad doodles here http://www.dave.com/trike.htm). Maintaining correct steering geometry (Ackerman) at all points of lean and steering angle was a bit of a geometric puzzle, but I got it pretty close, with no more than a half degree of error from 0-45 degree lean and +/- 20 degree steering.

Are you dead set on fly by wire leaning? My impression is that a leaner can work like a normal single track vehicle, i.e. with countersteering. Downside is that stopping at a light can be a challenge, as they tend to fall over without help, just like a motorcycle or bicycle. Most "free leaners" use some kind of lean locking mechanism to hold them upright at low speeds. Making a U turn on a 30% grade could be interesting though :D

Although the controversy about stability of tadpole vs delta is largely moot with leaners, I prefer the looks of the 'tad, and the simplicity of a single driven rear wheel. The exposed front wheels do add to aero drag though. I can't help but think the leaning trike is a better solution to stability than something like the non-leaning Aptera with it's semi truck width. Maybe the Aptera is a safer (as in less product liability exposure) for the masses though.
 
#5 · (Edited)
Ive been having a design competition on a 3d forum and have found a pretty decent design... :D

So the outer and inner design is pretty much complete (with some minor modifications)

The frame will be simple, with most of it will be visual (the roll bar behind the seat, the dual tube sides with crossmembers and so on.
Some interior framework needs to be designed aswell as fit the leaning mechanism into the front end.

The body will be moulded in fibreglass and add structural strenght to the vehicle. A core-material will be used (similar to surfboards) and strenghtened by glass and carbon fibre tubes (fibre socks) that will be sandwitched into the composite.


Im not sure of the weight anymore, but im guessing somewhat under 200kg inkluding a 15kw drivetrain and 4x 12V batteries (as placeholders for LiIon/LiPo batteries)


I have a question.. :)
Is it possible to connect a battery pack in such way that i can easily while driving shift between power configs?
Shifting battery config could be like shifting gears :)

Im thinking 1S4P (1 in series, single, 4 in paralell) or 2S2P for tourqe on low revs, and 4S1P for highspeed with low range.

i also been concidering if i can connect a separate 1s4p 12v battery connector on the existing batteries regardless of their propulsion configuration.
Meaning, can i connect the same battery pack with both 12v 4paralell and 48v outputs simultaniously?
 

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#6 ·
Really nice looking!

I love the idea of three wheels, and really want one, but the state laws here are goofy. Anything that has less than four points of contact with the road is concisdered a bicycle for legal purposes, which means having to get a motorcycle liscence. Getting the year long permit is easy, it's like a 10 question test, but getting the full liscence is signficantly more difficult and expensive than getting a regular liscence. :(
 
G
#9 ·
See, there in lies the rub. You have two options to get your liscence: take a class at the local college. Easy, but they always offer it as a night class, and I work nights.
Well that is a bummer but I am sure you can find a private company that will fit your time constraints. There is always a way around the issue and getting your motor cycle license is well worth the time, money and effort.

Pete :)
 
#11 ·
Ohio has seperate two and three wheel motorcycle licenses. I have had my motorcycle endorsement for a couple decades now. I always wanted to get my trike endorsement but never had access to a trike to do it. Maybe that's a good excuse to build an EV trike! :D

Our riding test was similar (with cones, etc) but we get a learner's permit after passing the written test. No passengers, no riding after dark, no freeways, etc., while riding on the learner's permit. I had been riding for a couple years before I actually took the riding test, and had heard all the horror stories of people hitting cones, wrecking their bikes, failing the test...

I was on a 77 Kawasaki KZ1000 and breezed through the test like it was nothing. I got five points off for showing off and doing a full panic stop instead of placing my front wheel on the line at the end of the test. Yes, I got penalized for being able to haul my bike down too fast! :cool:

The point is, if you can really handle your bike you can pass those tests. They are designed to weed out the people who are likely to kill themselves due to not being able to handle the bike.

Set up some cones (plastic bottles) in a parking lot and practice until you're confident.
 
#12 ·
I California, the motorcycle safety foundation offered a CHP (Ca Highway Patrol) approved course takes a full weekend, but gets you out of the DMV driving test and an insurance discount for having taken a safety course.

Love the trike design you came up with. In leaning mechanisms, I like the one off the Brudeli 625L. Simple, easy to understand from the website pics.
 
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