E-bikekit.com sale, My Chance to Build 4 Wheel Bicycle Car

denito

1 mW
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Apr 10, 2010
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Not sure if this belongs under e-bikes or general EV discussion, but I'm posting here because at this point I'm still only talking about bicycle hub motors/wheels.

As I'm sure most here at the forum know, e-bikekit.com is having a clearance sale on 6x10 motor wheels, $80 each if you buy five. I figure this is my chance to get four matching wheels to build an electric bicycle car! I brought the subject up with my wife and she didn't forbid me from buying them or threaten bodily harm if I bought them. Just to be safe, I'm hoping she'll forget all about the conversation and I can hide the boxes when they get here. j/k - actually my wife has surprised me with how supportive she's been of my electric vehicles hobby. I'm hoping that if I can build something that doesn't look too awful, she might be willing to ride in it for short trips.

I want to build something that looks like the old turn of the century (no not that century, the one before it) grand prix cars:

http://en.wikipedia.org/wiki/File:Marcel_Renault_1903.jpg

And yes, I will be wearing the goggles when I drive it! :twisted:

One thing I'm wondering - do you guys think it'd work ok if I attached only the inside half of the axle on these wheels and leave the other side free? Ordinarily I'd think I'd want the wheel fully boxed, but that kind of ruins the look don't you think? And the axles on these motors are REALLY thick; I'm thinking if I take a piece of 3/4 steel pipe and tap threads on the inside of it, I could screw the axle down into it and it would be very strong. No worries about it unscrewing itself - you have to have torque arms on it anyway, which keeps the axle from turning at all one the torque arms are in place.

Of course, I'd still have to deal with the wires on the other side somehow. Unless I put the wire side into the pipe, but that side of the axle is hollow, is it strong enough?
 
Lol this post reminds me of Johnny Cash's One Piece at a Time:

The back end looked kinda funny too
But we put it together and when we got thru
Well, that's when we noticed that we only had one tail-fin
About that time my wife walked out
And I could see in her eyes that she had her doubts
But she opened the door and said "Honey, take me for a spin."
 
denito said:
One thing I'm wondering - do you guys think it'd work ok if I attached only the inside half of the axle on these wheels and leave the other side free?
I would strongly discourage axle diameters below 1/2" (12.7mm). Even then, not knowing what steel the axle was made from, at least 14mm or larger would be my suggestion. What is your best estimate of the vehicle's laden (gross) weight and do you plan to employ suspension?
 
I am showing my ignorance. I think a 3 wheel bike is easier to license than a 4 wheel.
A 3 wheel is still considered a bike but 4 wheels get you into safety issues and law.

this is what I want for xmas

http://www.rqriley.com/xr3.htm
 
Check the ebikes-ca website about that one sided mounting. They have supplied some special motors for that. Maybe email them with a question if Justin doesn't see this thread.

The 9c axles are the larger ones, so they may be big enough. Any particular reason all 4 wheels need to drive? 4 motors worth of battery x 72v is gonna get to costing a whole lot more than your motors. You'll get 20 mph out of the 6x10 at 48v, so you'll need higher volts for any speed.

The 6x10 is a nice motor for lower speeds though, I just bought another, and will have a frontie and a rear. The rear is on my dirt riding bike, and the front is going on my commuter, to get me back to sane speeds street riding while still running a 48v battery to get up hills.
 
denito said:
Of course, I'd still have to deal with the wires on the other side somehow. Unless I put the wire side into the pipe, but that side of the axle is hollow, is it strong enough?

I'd be really hesitant about supporting a 9C axle from one side like this. They are just 15mm diameter at the bearing, while most other hub motor axles are in the 17-24mm range. We had a customer snap one of the 400 series project motor axles on a quad EV with the hub supported from one side, and that was from solid 3/4" (19mm) steel that was machined down a bit to fit inside wheel clamp on his bike. Still much beefier than a Nine Continent axle.

Turning Axle Small.jpg

Wire Groove.jpg

The ball bearing size on the Nine Continent side cover is 15mm x 35mm and 12mm wide. You could press that out and replace it with the 6003 bearing size which would give you a 17mm opening to play with if you have the tools to machine your own axle or axle adapters.
http://www.vxb.com/page/bearings/PROD/17mm/Kit7560


Justin
 
Dang, he must have some kind of alert when we type his name! No reason you can't design a quad with forks to support both sides though.
 
Thanks for the info about the axles, Justin. If it's at all marginal I think I'll go with the safer option of supporting both sides of the wheels.

The only problem with using forks on the front wheels is I think the stem rising up so high would spoil the look. But wait - why do the forks have to have the pivot on top? Maybe I can put the pivot on the side:
sideturnforks.png


BTW I do plan to make it full suspension. I'm thinking I could use go-kart or minibike struts that combine the spring and shock absorber; not sure how I'll mount the suspension yet.

I was already planning to do the back wheels like in the picture posted by whiteblade, but I hadn't seen an example before. Thanks for posting that.

As for the battery costing more than the motors for this, as Dogman points out, well two things: one is I'm going on faith that by the time I finish this project the battery for it will exist. Maybe Ping will come out with a higher-C rate V3.0 battery, or perhaps the price on LiFePO may come down. Or I might be able to buy a used battery pack from a totaled hybrid car and salvage cells from it. In the mean time, I'm thinking that I could borrow the 48V 20AH ping from my two wheel electric bike and modify the current limit on four controllers *down* to about 12 amps each. Or just only power 2 wheels at a time. That won't get me going very fast, but it would be enough to make test runs with.

Edit: I don't need to power all four wheels, I just want to.
 
4 wheels and a motor make it a "motor vehicle" in almost all locales. If you keep it slow and the cops in your area are reasonable, they may let you get away with it. Unlicensed golf carts on the street without issue would be a good indicator. Otherwise you may end up as an LSV, Low Speed Vehicle, with special requirements like a windshield and other things, and licensing. Check the legalities first.

That's why many of the newer vehicles are 3 wheel. That 4th wheel can kick in lots of special requirements for cars.

John
 
I agree on 3 wheels, built right . they are and/or more staple as 4, and they are still...bike / motorcycle...a lot easier to run legal. (depends on your state/county)

Any 1 got more info/links on the pics above....looks like some huge caps on that thing...like to know more on that setup.

Mine has 2000 miles on it now...has it 50 in the draft...but I like the looks of the 2 seater....
 

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nineball said:
I agree on 3 wheels, built right . they are and/or more staple as 4, and they are still...bike / motorcycle...a lot easier to run legal. (depends on your state/county)

Any 1 got more info/links on the pics above....looks like some huge caps on that thing...like to know more on that setup.

Mine has 2000 miles on it now...has it 50 in the draft...but I like the looks of the 2 seater....

Not sure if you ment the pics i posted but here's a link : SUN-E-TRIKE tm SOLAR POWERED BIKE

http://www.solartrike.com/canopytandemsolarquad.html

They are using two dual hub motors 408/4011, 36v ,13-16+ mph

atsa00001.jpg
 
denito said:
The only problem with using forks on the front wheels is I think the stem rising up so high would spoil the look. But wait - why do the forks have to have the pivot on top? Maybe I can put the pivot on the side:
sideturnforks.png
I can't remember if I posted them in my ARTOO trike thread yet or not, but I have a bunch of sketches on various ways I worked out to do exactly what you show there.
 
If you put the pivot on the crossbar you would have the beginning of a trailing arm suspension.
otherDoc
My good drawing program went down with my old computer. Damn. Paint really sucks! but that copper colored solar 4 wheeler is quite cool! Who made it? Oh I see the website.
 
denito said:
As for the battery costing more than the motors for this, as Dogman points out, well two things: one is I'm going on faith that by the time I finish this project the battery for it will exist. Maybe Ping will come out with a higher-C rate V3.0 battery, or perhaps the price on LiFePO may come down. Or I might be able to buy a used battery pack from a totaled hybrid car and salvage cells from it. In the mean time, I'm thinking that I could borrow the 48V 20AH ping from my two wheel electric bike and modify the current limit on four controllers *down* to about 12 amps each. Or just only power 2 wheels at a time. That won't get me going very fast, but it would be enough to make test runs with.

Edit: I don't need to power all four wheels, I just want to.

Two wheels powered or four, 12 amps or 25 each you are still close to the same top speed. You either need more volts or a faster wind motors.

But slow wind four wheel drive would be pretty unstoppable. Make it a one seater and throw on a roll cage and you would have a blast off road.

Gary
 
Off road might be the way to go. It'd get around some of the difficulties of making a four wheel home-made vehicle street legal, for one thing, and if I didn't care about top speed I could just use two 48V 20AH batteries (I have one already). I should rebuild the hubs into 20-inch wheels to get more torque, and I think it would simplify the steering and fully supporting both sides of the axle if I didn't have to deal with as tall a wheel. Hmmm... I'm not a real big off-road kind of guy but there are probably a number of places here in Oklahoma where such a vehicle could be ridden. Also I wonder what the legality is of riding a slow vehicle in the grass along the side of a road, instead of on the road? I see people riding farm equipment that way all the time, but in this state farm equipment gets a lot of special exemptions. Maybe I just need to paint it John Deere green and I'll get a free pass...
 
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