Electric 6 wheeler?

[Beeman]

I've been thinking of doing this too... was thinking of building my own controllers too!

I personally would go with two electric motors (A/C) and chop a DC voltage into pulses (PWM) so that you can control the frequency and therefore speed of the motors.

A couple things to keep in mind:

-With Batterys, you basically want the highest voltage (form serialing them) so that you don't lose out on line loss.

-Motor controllers could be constructed as simple as high amperage relays (solenoids) much like a winch controller.. They are mechanical and wouldn't last too long (they are based on the amount of cycles they go through)... they also wouldn't allow you to have speed control (also, if you go the DC route with DC motors you could control the speed by controlling the voltage... but unfortuantly this would not allow for high torque at no rmp).

-You can construct a controller using high amp mosfets much like the commercial types and control the speed (if DC) with pwm to get the high torque at low speed.. or for AC where your pwm circuit will generate the AC pulse and your mosfets would control the direction.

[JRP3]

Thanks Mike, that's sweet. Gives me some numbers to work off of. I don't need 4 hours of run time so I can use half the batteries, though I'll probably use 4 12V to get 48 volts for more power. Those old GE motors were pretty heavy for their output I think so a modern pancake motor like an E-tek would help with weight and a modern controller should be more efficient than the stepping contacts they used. If the price of lithium batteries ever comes down to earth I could upgrade and lighten it up even more. Can't wait to get my hands on a vehicle. Are some better than others for this? Lighter weight, more room for batteries, etc? I suppose I'll just have to take whatever comes my way and make it work.

[JRP3]

-You can construct a controller using high amp mosfets much like the commercial types and control the speed (if DC) with pwm to get the high torque at low speed.. or for AC where your pwm circuit will generate the AC pulse and your mosfets would control the direction.

Yeah, I don't think I want to get into building my own controller, since I don't know how I should be able to find a used Curtis or something for a good price. 48 volts won't require anything exotic.

[jpswift1]

Here are the three electric Amphicat 6x6 videos that I came across on Youtube.

[JRP3]

Nice! I sent a message to the guy to find out more about what he did, don't know if is account is still active since he was trying to sell it back in Oct.

[JRP3]

Got an email from the guy in the videos, he's still got it. It's just running with an on/off contactor at the moment, no controller, though he does have a Curtis for it. He's got it geared way down so he doesn't kill himself since there is no speed control It's using a GE motor from an old Elec-Trac riding mower.

eBay Motors: Amphicat amphibious 6x6 AATV (electric conversion) (item 290165756771 end time Oct-08-07 22:41:02 PDT)

[mudslinger]

That is just too cool. With all the hybrid technology out there I am surprised that someone hasn't come up with a hybrid AATV, you could pivot steer it if you had two motors, one for each side, and regen for when you are going down hill, saving the brakes, and put a really small engine in it to recharge the batteries when needed, or just skip the engine and put in more batteries, especially lithium ion.

[JRP3]

I don't think a hybrid AATV would be worth doing. The nice thing about all electric is you don't have to carry around a gas motor and gas tank and use the room for extra batteries. With lithiums you could even make the pack or packs removable and swap in charged ones like a cordless drill, but I think there is enough room to just carry enough batteries to run as much as you want. The electric Attex claimed 4 hours run time, that sounds like more than enough for most people, and that was with lead acid batteries.
I suppose the ideal setup for motors would be 6 small AC motors, one for each wheel. Then you eliminate all the chains and gears and have built in regen braking. Wouldn't be cheap though

[salamander]

Brushless DC Waterproof Hub Motor... maybe email these guys; they have lots of new tech electric motors and batteries: http://www.goldenmotor.com/

[JRP3]

Yeah, waterproof hub motors would be the way to go if I had the cash, and the time to engineer it all. You could have independent suspension without having to use axles and cv joints. Might even be able to use a lever/swing arm setup that moves parallel to the body to help keep the wheels tucked in close. As it is I'm still looking for one motor that I can afford, not to mention the AATV itself All I've got so far is a dream