have you thought about using a starter as the drive motor? im sure that would have tons of power you just couldnt drive it for too long..

 

You have a nice project in the works.
You might be able to get some build ideas from the Traxxas RC web site.
Traxxas - The Fastest Name in Radio Control! | traxxas.com
Or this guy with a Traxxas RC truck and some tire chains.
Traxxas summit pulling 70 pound kid on ice kid - YouTube
They had a setup down at the drags in Englishtown and the kids (and adults!) were going crazy over them.
Probably getting one for my son (and I) for his birthday.

 

I was pulling similarly sized kids on mine on clean pavement on their sled :P (Also, sorry, I never got notified of your post or I'd have replied sooner).

I went and got my third and fourth wheels today (Lowes, replacement hand truck wheels, $28/pair) and on the way home I stopped at Tractor Supply based on a tip from Dad. I found the item in the link below, a hub intended to have a sprocket welded to it:
V Series Hub, 3/4 in. Bore - 1180722 | Tractor Supply Company

For $9, it exactly fits the existing wheel chair axle, and with a little work, it will fit in place of the bearings in each rear wheel. I forget the exact measurements that were told to me earlier in the say, but the hub is slightly larger than the bearings and will have to be turned smaller. Might be able to do this in the drill press along with a rotary tool. I will try that and if it fails it's only a $9 loss. Then I will find someone with a lathe to turn it properly...

More to come very very soon, I hope!

Michael.

 

The latest update on my build:

In my previous update I described how I FINALLY found the right 'bits' to be able to put the wheels I want on the wheelchair axle that I have.

There's a problem, though.. I still need someone with a metal lathe to turn the parts slightly smaller so that they will press-fit properly. I looked at a lathe recently that would do it, but at $500, it will be a very long while before I can afford it.

In other news, I've been given a larger, more powerful wheelchair axle/drive-unit which was designed to be used with 11 inch tall tires so I will not be losing torque by changing to the 10 inch tall tires I want (I will in fact be slightly gaining torque). The actual axle on the new unit, however, is not the same as the axle on the old unit, it is smaller (3/4 inch on the old, 5/8 on the new), so now I have to either exchange or replace the sprocket hubs with an appropriate sized pair, and still find someone to turn them down slightly for me . . .

The new drive unit, powered by a single 12v marine battery and my radio-control electronics did push an albeit-mostly-gutted Corvair half way across my yard, though, on uneven grass! I can't wait to see what it does on 24 or 30 volts!!!!

Also, the new drive unit is equipped with a 24 volt electric e-brake. When supplied power, the brake releases. When power is lost, however, the brake snaps shut. With all of my strength, I cannot force the brake to slip when the springs are holding it shut! I've even put a ratchet directly on the nut that retains the brake pad and was unable to turn the brake directly without a significant amount of force! I gave up for fear of either tightening the nut so far that something was damaged (it's only a 1/2" hex) or that I'd break the ratchet or socket (Craftsman 1/4" drive). The brake should turn out to be a good safety feature if I am capable of controlling it. With it's manual over-ride, it will at least be a great parking brake! I will have to see if there is any way to control it gradually so that it can actually be used as a brake while driving.

Anyways, that's all for now.

Michael.

 

sounds like some real progress. 24v should wake it up significantly!

 

Imagine what'll happen if I can get my hands on enough 6 volt batteries instead and run the sucker on 30 volts! My electronics can handle up to 33 safely, and I am sure that the motor wouldn't care about an extra 6 volts.. especially if I take care to keep it from over heating!

Michael

 

In regard to overvoltage consider the following.

Wiki Voltage optimisation

The Highs and Lows of Motor Voltage

 

Having read and appreciating that information, I will say that I have seen similar motors run at half-again or even twice their rated voltage. I will also point out that the motor is designed to be a variable speed motor so I dont think I have to worry too much about undervoltage. Thirdly I've not yet gotten to run it at even 24 volts, only 12, so I may very well decide that 24 is more than enough for what I want. We'll see sooner or later.

I emailed a particular battery supplier today to see if they would help out with a selection of appropriate batteries and possible a touch of spnosoring.. I will let you all know how that turns out once I know..

Michael.

 

guys are juicing 12 or 24v motors with 200+ for those electric drag bikes. i like that.

 

I'll bet they don't last very long . . .

 

ya but they go fast!