Turnigy SK3 5045 500 kv - looking for car esc

Hello! I am try to build a motorized cart for a little girl. Ideally, it would have a max speed of 3mph. I have a 5045 500 kv outrunner brushless motor and a 10000mAh 6s lipo pack. I know the motor has a high kv, but she is only about 60lbs. What would be a good car esc that is compatible with both of these? I would like it to go forward and reverse and for it to be easily programmable, but not too expensive. Also, how do you know the number of poles the motor has? I tried to look it up online, but have not been able to find a good answer. Thank you!

Here are links for more information:
Motor: https://hobbyking.com/en_us/turnigy-aerodrive-sk3-5045-500kv-brushless-outrunner-motor.html
Battery: https://hobbyking.com/en_us/multistar-high-capacity-6s-10000mah-multi-rotor-lipo-pack.html
Here is an esc I was thinking about, but was unsure that it would work: https://hobbyking.com/en_us/hobbykingr-tmbrushless-car-esc-100a-w-reverse-upgrade-version.html


3 issues I see:

  1. You are likely going to have to gear this way down to get 3mph
  2. The ESC you are talking about uses a servo interface. Do you have experience programming an arduino to talk to servos?
  3. This will be a motorized vehicle that a child will be operating. You will have to put much thought into safety. Failsafe modes. If something goes wrong, it stops operating. If the brake is applied, the motor cuts.

Are you converting an existing kiddy cart or making one from scratch?

Just about any 6S capable 60-100A ESC will work. Not the one you linked though, because it only supports up to 4S, instead of 6S. But I would also suggest you reconsider.
500KV x 6S x ~4V per cell = 12000 RPM. Whatever you intend to use as gears to get that down to a walking speed, Im not sure I would want my little girl close to that. Or for that matter, to a 240WH lipo battery.

If you want something to go slow, yet have enough torque to move a (small) human, you may need a brushed motor. And they tend not to be cheap...

Also, how do you know the number of poles the motor has? I tried to look it up online, but have not been able to find a good answer. Thank you!

Two ways - take it apart and measure the number of magnetic field reversals round the rotor. That's
the pole count.

Without disassembly: Put a few amps between two of the wires of the motor, count the number of detent positions you get
turning the shaft, that's the number of electrical cycles per revolution, which is half the pole count.

We are making it from scratch. Do you think a 12v brushed motor work? Thank you for your help!

That motor is rated at 1300 watts.
I have played around a fair bit with electric minibikes. 500 watt brushed motors that push a 60lb child 17mph.
And a 245lb adult 12mph. Or course, we modified them to get more power!!! :smiley:

Here is a motor/controller/throttle kit that would go a long way towards your goal.

Great, thank you! Can that motor be programmed with Arduino?

I am sure it could.
What do you want out of the arduino that the commercial controllers do not provide?
Myself, I would need a strong reason to give up the safety and reliability of a commercial unit.

If you want just the motor, here is a page of 24v motors (that would run well on a 6S LiPo)