Unicorn Motor Controller

acornstu

10 µW
Joined
Feb 2, 2009
Messages
5
Hey guys, I'm not the smartest guy around but me and a buddy are building a drifting wheelchair. I'm stuck because another friend sold me a new winch motor cheap. Winch controllers are expensive af for some reason.

It's a 12v 1.5hp motor. Not sure what the 3 connection on it are for. Forward/reverse or grounding wire maybe?

The problem here is that the vast majority of consumer level contollers are all 24v, 36v, 48v, etc.

I figured 750 watts per hp making it roughly 1,125 watts at 12v and 92 amps.

So basically I need a 12 volt brushed dc motor controller capable of 100 amps.

Alternatively if this is going to be a $300+ control box I'll just wire it up to a big relay and a push button somehow. And if it catches fire oh well. $300 can buy a pair of 750 watt 24v geared bicyle motors. Not sure on the exact gearing on either but the 3 pairs of wheelchair motors I have are 24v 240 watt. Don't know if the bike motor is brushed or not either.

Should i just get a different motor or two different motors and save this 12v motor instead?

Would it be possible to run 2 seperate motor controllers and motors and use 1 throttle?

Sorry. Sat down to type and busy at work now but wanted to post so i can shop tonight. I wrote the post in sections between work and lost track of wtf i was saying.
 
You'll need more power than 1kw to drift a wheelchair unless you're on ice. Also, you'll need anti wheelie but I'm sure you've thought of that.

There are plenty of big ass motors out there for cheap. I don't have specific recommendations, but you'll probably be better served using something other than the 12v winch motor. Yes, the 3 connections are so you can quick reverse it.
 
I'd just use the wheelchair motors you already have--in bursts you can run them at much higher power levels than what they are rated at, using double the original voltage, and if you have three pair then when you burn one out you can just swap them. :) If they're not enough, you can get bigger powerchair motors, though they get heavy quick.

48v brushed motor controllers for scooters are relatively cheap, even up to a couple of kW.

Since you need more torque than speed (and doubling the voltage will nearly doulbe the speed), then if you use the motors (presumably with their gearboxes) to indirectly drive the wheels via chain, you can use bicycle sprockets to change the gear ratio to increase torque (bigger gears on the wheel, smaller on the motor), decreasing wheel speed.


To drift a chair without flipping it, you're probably going to have to either take the tires off the wheels and run on the rims, or use plastic tires.

Adding extra-long wheelie bars may help with torque-flips, but if it's possible for tires to grab the ground in sideways motion the chair will just fall on it's side and dump you and slide into you, so if you use tires that have any traction you're risking the crash every drift. Doubling the width of the chair might stop that, but is probably not practical.


I reocmmend independent throttles for the two wheels, so you can control everything better and initate drifts more easily.

Also, if you don't put freewheels between motors and wheels you can use electric braking if the controllers support it.
 
Thanks for the tips. I've been thinking about pvc sleaves for the tires. I'm pretty sure at least one extra pair is a direct bolt on for my model of powerchair. And I'm not real worried of a rollover. I am hardly on it. I just watch my friends ride it and laugh.

Looks like I'm doubling the voltage. Lol thanks guys.
 
acornstu said:
I'm pretty sure at least one extra pair is a direct bolt on for my model of powerchair.
Many of them just clamp right on to the chair's frame tubes, with a rounded slot directly in the gearbox lid.
 
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