Looking for a motor.

[loki7714]

Looking for a DC motor somewhere in the range of 2-3 hp and some way to control the speed. Any help much appreciated, I searched Google for hours last night with very little to show for it. It's for a medium sized one seater gokart project. P.s. Is this the right forum for this to be posted? (noob)

 

[bzhwindtalker]

if you don't mind some work, a car alternator would work, be cheap & good.
then you would need a sensorless brushless controller, available from lyen here or from bmsbattery, or here http://holmeshobbies.com/product.php?productid=242&cat=20&page=1

good infos here : http://endless-sphere.com/forums/viewtopic.php?f=30&t=16328&start=0
this set up would be cheaper than etek or mars motors witch are dc brushed motors, but for 3+hp, you will need a healthy controller, pumping 60+amps at 48v. Not many sensorless controllers can do that.

 

[REdiculous]

Even though it could probably work for a gokart, I'm not really recommending it. Just sayin'...I just started trying a treadmill motor and it's pretty cheap and seems pretty beefy...

If I'm pretty generous about what my "freebies" are worth then it's cost about $400 so far. Actual out-of-pocket cost was $250 for the motor, controller, inverter and 20ah 12v battery...the rest was scrounged. In order to really call it 2HP I'll need 2 more batteries tho...another $100. At this point I get a 2 mile range when I treat it more like a small motorcycle than a bike...

I've got ideas to improve efficiency, but right now it sucks pretty bad...this is why I can't recommend it. If it turns out that I can get decent efficiency then..maybe. Then there's always the bearings and brushes in the motor...iirc, the average motor life is 2yrs..in a treadmill where dust and road debris is a non-issue.

Just a heads-up..pursue at your own risk...YMMV and all that.

 

[loki7714]

Yeah someone else pointed out that topic and it seems really interesting but that guys english isnt the greatest and my understanding of the principles and electronics terms he's using is even worse. Any sites with a lil background info?

 

[dequinox]

This is the motor I use, and I recently upgraded it to 36v. I have seen it take up to a 3.4 kW surge and survive just fine. It gets a little hot but cools off after a couple hours :lol:

http://www.monsterscooterparts.com/24-volt-900-watt-motor-controller-throttle-kit-premium.html

Seriously though 3.4 kW is equivalent to about 4.5 horsepower...thats pretty good in my book. This is a good kit, or there are 1000 watt kits that run on 36v that might be better. By the way I didn't get that kind of power from the kit they show with that motor... I got it from the Yi-yun yk43b controller. It's a monster...quite frankly. You can sometimes find these parts on ebay also.

 

[loki7714]

Wow finally a pretty cool looking motor for a decent price!

 

[dequinox]

Yeah it's not bad...there are other motors on there two that aren't too much more expensive that will take 36v a bit better probably. This one will take 34 amps continuously ...at least that's what the label says. I got 22mph out of the kit in that link...but you're putting it on a go kart so it might not do that well. Karts weigh a bit more than bikes...

 

[loki7714]

True, true.

 

[amberwolf]

This is the motor I use, and I recently upgraded it to 36v. I have seen it take up to a 3.4 kW surge and survive just fine. It gets a little hot but cools off after a couple hours :lol:

Just remember that it probably can't sustain that kind of power for any length of time, especially if it takes that long to cool off.

I used similar (but much lower power) motors by Unite for early experiments, and put far far less power thru them, and the windings burned to a crispy uninsulated black pretty quickly if I let them get hot for long. Should be pics of one in my early blog posts.

If you can get the heat out of it, it may last longer. But the comms and the brushes and the windings will get hot fast at overcurrent/voltage, so you would need to force-air-cool it to keep it alive.

 

[loki7714]

Im thinking i may try that motor with two used car batteries and possibly a solar panel.