[ThatHpiGuy] had a problem. He wasn’t impressed with the performance from his kids’ electric-powered Mini. The 6 volt system was anemic at best, and was just begging for an upgrade. Pulling off the seat and checking the undercarriage, [ThatHpiGuy] realized the motor and gearbox were a perfect fit for the Turnigy 2300 Kv motor from his R/C short course truck. A couple of screws later, 
and he had the fastest ride-on toy on the block. Since this was a quick hack, [ThatHpiGuy] kept the truck’s R/C receiver, electronic speed control, and 2 cell LiPo power setup intact. The result is a cooperative system where he controls the throttle via R/C, and his kids control the steering.
That steering is still a bit of an issue though. Like many kid toys, the Mini only has one drive wheel, in this case the right rear. If [ThatHpiGuy] pours on the power a bit too quickly, the single wheel either spins or forces the car into a hard left turn. Aside from that, it looks like both [ThatHpiGuy] and his children are having a ball with this hack. The car will even pop a wheelie from a standing start! You’ve got to see it after the break.
I wonder if you can fix the driven wheel to the axle and then use it that to drive the other wheel. It probably won’t have the best bearing points on the chassis though.
I am really surprised he didn’t just turn the gearbox into chips with that motor.
yeah i’m too surprised that the gearbox did’nt just go ggrrrrrrrrsssshhhhhhhh.. lol
That gearbox isn’t long for this world…
there’s a reason only one wheel was driven, hint: https://en.wikipedia.org/wiki/Differential_(mechanical_device)
get a grip!!
THE only reason to have a diff is for corners on SEALED roads, otherwise every corner is a power slide!
on full size cars we have diffs to stop tyres scrubbing out and “sedate” cornering.
On dirt if I’m driving a 4WD that has lockable diffs, they stay locked!!!
Exactly this.
I can understand having a diff in a RC toy car, because those things are hard to handle as is. But in a powerwheel? Nah, no need at all.
Most go-karts use a live axle, though the chassis is designed to flex and lift one of the wheels off the ground in hard turns.
I think it’s not relevant in the case of a toy car for kids. It doesn’t matter much if one of it’s wheels slip during turning or not, we’re not talking a ton of weight here. No need for a diff.
Nah, cheap go carts have solid axles all the time. They did it because it was cheap. And those plastic wheels will slip on a turn anyway.
Dude, your the best dad ever. lol. Going to so switch out my daughters motor, she would love to go faster.
Looks like they were actually getting the hang of counter steering too. Great Idea.
Didn’t know Ricky Gervais was into hacking stuff :)
Oooh, chimpanzee that! Child hacks.
you could build a throttle circuit with a 555 timer and some passives.
not with a brushless motor you can’t!!
this is one of those times when a 555 can NOT replace an Arduino
looks like he’s using a standard brushless speed controller, a 555 works just fine to control that
I think the point is with a micro you can do things like throttle mapping. You could also put an encoder on the front wheel and do traction control!
I have to disappoint, traction control isn’t that easy to implement. Requires a lot more than just an encoder.
Source: i’m a car enthusiast working in the IT of the company which invented ABS and ESP. One of the old ABS devs explained it all to me when we were bored on our winter testing facility up in Sweden. It’s complicated.
In it’s most basic form yes it is. I worked with high school students and implemented it in 2009 for FIRST robotics. We had plastic wheels on a plastic floor. We used encoders and current sensors and compared the wheel speed of the driven wheel to a coasting wheel. If they were too far out of balance we cut power to the driven wheel. You can also look at the current and if you see it drop sharply then the wheel is spinning.
Throttle mapping would also be a huge help, to set acceleration curves.
Stability control is not an option on one wheel drive.
I mean this was pretty much plug and play, so compared to this mod yes it would be a bit of work.
sure you can.
a throttle circuit is different than an ESC. I believe Lord Nothing is refering to a simple 555 based PWM / PPM generator circuit which could replace the remote control receiver inside the car so the kids cold control the throttle locally. This signal goes into the ESC and the ESC is what chopps up the DC power from the battery to form the 3 phase square waves for the BLDC motor.
just google 555 servo controller. escs use the same pulse timing as servos do. so all you are really doing is replacing the receiver with the throttle control circuit.
exactly. You are changing the PWM duty cycle for te old 3 pin analog RC servo. A 555 with a couple of diodes and a port plus cap is all you need to generate the signal.
I designed my ESC from scratch and played with RC in my high school days.
I just keep thinking about another motor & gearbox, spinning the other wheel. A helmet would probably be a good idea…
I think this would be a great solution, I bet it would be pretty easy to attach. I wonder how much it would cost…
about $30… ohh not the helmet, carry on then.
I think he is having more fun than the kids, powerwheel hacks done by the best dad’s earth has to offer.
Mario Kart: Grown-Up edition
Control your own child
This is exactly what is going to happen once I have kids ;)
How lucky is it that the brushless is a drop-in replacement? Same shaft size and mounting holes even line up.
That motor size has been the de facto standard motor size for R/C cars, power screwdrivers, hair dryers, power wheels, and hundreds of other devices for at least the last 30 years. I remember using them in my R/C racing days, over 25 years ago (now I feel old), and we referred to them as “540” size motors.
I’m not surprised in the least that the new brushless R/C motor fit the power wheels. It’s kinda like the smallblock Chevy V8 of the electric motor world.
Don’t feel too old! I remember those Mabuchi or Johnson 540 (and 380, and 750) sealed endbell cans fondly. I still have my commutator lathe downstairs in case I ever get tired of all this brushless stuff :)
Glad I’m not the only one!
I actually still have a few 540s and 380s sitting in my old R/C hobby box. I don’t think any of them are newer than 20 years old.
I dunno, it makes sense for motor manufacturers to use standard mountings where they can, so the industry can use standard parts, and when you pick a motor you can pick it just based on it’s power or speed. Though to see it in a little plastic toy car is impressive, you’d expect them to cut corners where they can.
Check out http://powerracingseries.org
Isn’t NASCAR all about turning left too?
How easy it is when you happen to have just the exact right motor
That’s awesome.
Needs another motor.
Wheelies + no helmet = drain bamage.
Just add another motor on the other rear wheel and thats it. you can even get a cheap remote, disassemble it and put it under your child foot, so he/she can control the speed also.
Dont forget that it has no breaks..
And plastic tyres will not last long, but..
This is cool! Right now my kids just have a one of the powerwheels mini 4-wheelers that’s towing a trailer with an old car battery on it…