Help with "Offroad" Electric Kart

[joshb]

Hi,

I was hoping I could get some advice on an "offroad" electric kart in terms of electronics. I've been looking at Alien Power System's 12090/S Sensored motor and their 300A Sensored ESC.

Motor - http://alienpowersystem.com/shop/br...sored-outrunner-brushless-motor-130kv-18000w/
ESC - http://alienpowersystem.com/shop/esc/alien-300a-4-24s-evolution-3-esc-hv-sensored/

I'm mainly going to use it on flat grass sort of areas, which is why I'm thinking off-road but I don't expect to be going up steep inclines. It's going to be competing against lawn-mower (I think, or maybe they're weed whacker motors?) converted into karts. Would this set up work, and produce acceptable speed? After reading itsid's thread, I'm a bit concerned that I'm going to need enormous batteries to power this thing for more than 10 minutes. All the chassis' are going to be built from scratch, including mine.

Is a sensored motor really necessary? I understand it makes the motor run far smoother at low RPM but does it help in quick acceleration, or other "racing" type situations? I'm also not too keen on crushing bearings through sideloading the motor with a chain. Apparently, I can solve this with a "third bearing" on the end of the motor shaft and mounting said bearing on another piece of steel on the chassis. Is it really a problem that needs solving or am I just being over-cautious?

I don't have a huge budget (around ~US$1200 for the motor, ESC, batteries (Lipo or Li-ion, etc.), but I thought it would be fun to make an electric kart from scratch to compete against other student's karts.

Are there better options? I've read a bit about "Motenergy" on this forum but they have so many options I'm not entirely sure what to pick.

Any help would be appreciated, thank you.

 

[itsid]

Hi Josh,
I'm sorry you won't get much help with those RC motors around here.
yes they claim this and that and that other thing as well..
I personally doubt it (short runs maybe.. durable.. I don't think so)

So, IYAM motenergy is a much better option.
to determine how much power you need,
I'd like to point you towards this thread
I know it's a mouthfull to chew, but just give it a shot.

sensors on brushless motors make sense in two ways:
it makes it easier for the ESC to determine direction and speed, especially with slow turning motors.
relying on back emf as non sensored motors do is viable but only trustworthy on high rpms.
but again, these RC motors...
I personally will not provide any real supprt for them,
mainly because if I tell you what and where and when you might get confident that it's a good idea,
which IMHO it is not, and in the end it will fail eventually... and you'll be mad.
(maybe at us for not warning you sufficiently)
So my warning: if you do not know yourself .. run as far from all RC stuff as you can!

'sid

PS I admit I'd like their 5065 (150kV) to power my skateboard.. but that doesn't belong here really