All Wheel Drive Go Kart

[Cedric]

Hello, I have a lot of experience under the hood of a car however I am new to the kart area and am a bit unknowing so I was hoping I could get some help. I was wandering if AWD is possible with an electric street kart using multiple motors and some small CV shafts for the front. Either 2 motors (one in front, one in rear) or one motor per wheel. I know it is unnecessary however I have a huge preference to AWD vehicles, not to mention I love a bit of a challenge. I would love to get some feed back on this idea and maybe some help.

 

[firemanjim]

Im still thinking.....

 

[OzFab]

This subject has been discussed many times over but, IIRC, to date, no one has been successful (possibly through lack of trying). If you can pull it off, more power to you (no pun intended)...

IMHO, your biggest challenge will be balancing the motors; if one is powered or geared even slightly more than the other, they, obviously, won't run even & one end of the kart will be pushing more than the other. Using 4 motors will only multiply the problem...

 

[Doc Sprocket]

Normally, the greatest challenge you would face (assuming engine-powered) is getting that pig to steer, and not break components due to driveline bind. Under normal circumstances, this would be accomplished with up to three differentials- one in each axle, and one from rear to front. The center diff could be a viscous coupling, too. Anything that would allow a wee bit of slippage now and then.

With an electric project, I'm simply unsure. One motor, you'd still need the differentials. 2 motors, you'd need a diff in the front axle for sure. 4 motors? Good question. When steering, one wheel needs to turn slightly faster than the other, a fact I'm sure you're aware of. The real question is, can it? I suspect so. Since one wheel won't be mechanically coupled to the other, I think maybe the electric motors might allow enough leeway for this to work. It's all theory though, and based on nothing more than this coffee I'm drinking right now...

 

[Cedric]

I couldn't sleep last night so I sat up thinking of ways the drive line would work and Here is one of my ideas. (hopefully it will load) It has 2 motors each connected to an open differential. I thought of using all 4 batteries and a singular combined power source to] try and keep the 2 motors operating as close to the same as possible. I also thought to wire the motors in parallel to drop the ohm impedance in half (got the idea from my subwoofers). This is just one of my ideas for how it would work, anyone see any flaws? you guys have any ideas or thoughts on it?

On a related note is a gearbox needed with the motors?

Thanks.

 

[dcastillo]

http://www.youtube.com/watch?v=iYR4344zpTw&feature=youtube_gdata_player

 

[OzFab]

One possible problem may be that the motors are underpowered; what are the specs?

 

[Doc Sprocket]

One possible problem may be that the motors are underpowered; what are the specs?

I'm with you. Cordless drill motors? Be okay if you're pushing a 5-year-old at 2 1/2 MPH, otherwise- totally underpowered.

 

[Cedric]

Oh, I was just using the site from the "stick" post, I asked in "Electric Projects" with no answer yet wandering what motor to use, and if a gear box is needed with it what gear box to get,along with what batteries to you. I was thinking 4 Optima Yellow tops but I am open to suggestions.

 

[ML-TOYS]

Just build 4 drive wheels. Custom build front spindle and wheel to accomidate a high power scooter motor on each, and dead axle on each rear. then run power either series or parallel, cant remember which causes stall from my r/c days rock crawling but you dont want it.

And now i may have given myself another project to try.

 

[OzFab]

The imoprtant spec to consider when choosing batteries is the CCA (Cold Cranking Amps) rating; the higher the rating, the better the initial jolt will be & the longer it will sustain that amount of torque...

As for the motors, heres a simple guide: 1000watts = 1.34102209 hp. IMHO, anything under 1kw is underpowered. The kart in the vid above has a total of 4kw which equates to 5.36hp. Something to think about...

 

[Cedric]

So would say two 5hp compressor motors like these work? I thought it wouldn't since it has a 230V rating.

http://www.ebay.com/itm/New-5-HP-Co...203?pt=LH_DefaultDomain_0&hash=item2a1d77be53

 

[OzFab]

Umm, no because it's a 230v motor; how will you supply that much voltage (I could be wrong, lower voltage & higher amperage may offset eachother) but, I think a couple of these is what you're after

 

[Cedric]

That looks more like a go kart motor. So one of those at each wheel hooked up in parallel like the 0.5ohm picture with 4 gauge wire to 4 yellow top optima batteries; or would it be better to wire the motors the way the second 2ohm picture shows so the 48V would match perfect and the motors wouldn't be overvolted?

 

[itsid]

No, you need a controller to run the motor (one per motor!)
you should never even try to attach a motor like that straight to a battery (even on benchtests, that could end up being very unpleasant )

So, controllers... and find some that you can synchronise,
that is, they have a tachometer input at least,
or meant to run synchronised motors (master & slave setting)

You could eventually run two motors with just one controller, but the motors need to be identical (not only the same model, but the same batch!)
And if so, you need to find a controller that allows the resulting overall resistance you'll get wiring them in parallel.
NEVER wire motors like these in series.
If one stalls for some odd reason, the other one will blow before the controller is able to shut it down.

And for your cables.. I have the feeling you're talking about CarHiFi stuff..
Yeah well... no, not if you ask me

'sid

 

[Cedric]

I wanted to build this kart electric for a challenge and a learning experience and that is defiantly what I got. The only hands on electrical experience I have is (as you probably guessed) car sound systems and very low electricity projects (portable phone charger, solar toys, ect.) So it looks like I really need to do more research on the subject before I waste anymore of your guy's time. Do any of you know a good place to start aside from "Electric go kart" on google.

 

[Cedric]

And a quick question. on the hot line from the batteries to the motors I was going to put a variable resister connected to a pedal for the control, I am assuming that wouldn't work?

 

[itsid]

And a quick question. on the hot line from the batteries to the motors I was going to put a variable resister connected to a pedal for the control, I am assuming that wouldn't work?

No it won't

the resistor isn't a limiter, it's a consumer..
that means it'll drain the batteries (for no reason) and at the same time will get very _very_ hot.

That's why you need a controller, it toggles the engine on and off (too fast to notice) to reduce the power.

'sid

 

[Cedric]

Say, looking at the cost of parts, I am getting a bit apprehensive. I wasn't expecting this to be a $1.5K project, any tips for cutting costs?

 

[firemanjim]

Build a gasoline engine powered kart....