karld

hi members, im looking for some advice on using the existing method of a gas peddle on a 12v power wheels quad bike im upgrading for my son. im looking to put x2 brushless motors with escs powered by s3 10000mah lipos any suggestions?

thanks.

Maj_Overdrive

My Feedback: (11)

If you search around you can find the various forums for upgrading power wheels vehicles. The little I've browsed upgraded power wheels the trend is to stay brushed and up the voltage to 24v or more. Cost probably plays a factor in this trend but there's downsides to going brushless. Unless you go with sensored brushless motor startup can be an issue with such high loads. Brushed doesn't really care if the motor is stalled, brushless esc's have big issues when the motor gets stalled or has really high loads during startup. Even with sensored you'd be much better off with a lower kv and higher voltage setup, it'll be able to handle the high load better and not heat up as much.

Just have a look at the V Twin (twin 1/10 VXL) setups guys were using on EMaxx's before affordable 1/8 systems were a available, the performance is basically equal. And by that example, you have twin 1/10 3s brushless systems on a 1/8 monster truck and you want to use them on a much heavier vehicle with a rider. Yeah I know you'll be gearing it to go a lot slower but will it be enough to keep those motors cool pulling at least 5 times the weight?

Google for those power wheels forums, maybe someone has done it. Or at least used a rc based esc with a servo tester for the throttle and you can see how they did it. If it was me I'd stay brushed with something like a Traxxas 775 or Dewalt 820 drill motors. The Dewalts are the closest you'll get to 1/8 brushless power they're cheap at about $30 a pop and they're damn near indestructible. Hook them up to a pair of Castle Mamba Monster or Tekin RX8 esc's as they can do brushed and run them on 4s lipo with how ever many mah you want. The whole setup will be a little more expensive due to the esc's and going 4s instead of 3s but it'll be more durable and without the brushless complications.

karld

thanks for the response. iv already got the parts to hand so ideally want to use these and overcome the stumbling block i got too. ive tried micro controllers but they need resetting each time theres a brake in power

The Saylors

When i was a kid my dad put car batteries in mine and i could pop such hard wheelies that i could flip over with the stock plastic tires. Very fun but my grandma didn't like my dad after that, she's the fun police.

Chumley54

Just a thought, but a servo tester (I paid around $10 for mine) puts out the proper signal. Here: http://www.amazon.com/4-8-6V-Tester-...=servo+testers



It uses a pot to control position. So put a servo arm on the pot, spring load it to a pedal and you could vary the inout to the ESC as if it was a radio receiver.

Cheap, and will work. It would require it's own battery, or if your ESC's have a BEC, you could use that source.

Maj_Overdrive

My Feedback: (11)

Sorry, I talked about the motors and esc's a lot and barely mentioned using a servo tester for the throttle. Chumley54 gave you a link and everything. There's many to choose from with these servo testers but anything with a dial like that will work. Just attach an arm to the knob, then some sort of rod to the arm and then to the pedal. You can hinge the stock pedal with any old hinge, make a new pedal, etc. The hard part will be mounting the tester and adjusting the linkage.

karld

ill give that a try. what are your thoughts on a pedal throttles used on mobility scooters or modifying a thumb throttles for ebikes? do you think these may work? they have the pos/neg and source connections

Maj_Overdrive

My Feedback: (11)

I really have no idea how they would work and whether or not the pwm signals would match up. People use rc airplane esc's with ebike throttles all the time. But the pwm signals are the same, it's just 0-100% throttle. With rc land vehicle esc's the pwm range goes from 100% reverse to neutral (0%) to 100% forward. I don't know that you'd be able to calibrate a rc land vehicle esc to an ebike throttle due to the different pwm range. Those that use a land esc with an airplane transmitter typically just modify the transmitter so it will center the throttle at neutral, I guess you could do the same and adjust the mounting or something so the pedal returns to the neutral position. With a servo tester or ebike throttle you'll need to calibrate it to a rc land vehicle esc first, then limit pedal travel to prevent it from going in reverse.

Interesting as I hadn't considered reverse before this. You haven't mentioned what motors and esc's you'll be using but there's basically only one option for reverse no matter what esc you're using if you're going to use a throttle pedal. Airplane style esc's don't have reverse. Land vehicle esc's do but you need to limit pedal travel to prevent going into reverse. The only way I can see reverse working is by running two of the motor wires through two relays. Actually 4 relays, 2 for each motor. If you switch any two wires on a brushless motor the motor reverses direction. So with 2 relays per motor you can set them up for forward and reverse. Wire the relays into a switch that simply energizes one relay to close it while the other remains open, the switch then reverses which relay is open and which is closed. The esc always operates in forward you simply use the relays to reverse polarity on 2 of the motor wires to change the direction of rotation on the motor.

The Saylors

All this talk of awesome barbie jeeps makes me want to build an electric go kart made for tire smoking lol

karld

ive ordered the thumb throttle it should come within a week and will update when trialed. i will also sort some relays ready. fingers crossed it works....

Maj_Overdrive

My Feedback: (11)

Maybe I didn't explain the throttle issue well enough, let me try again. You know the twin stick airplane style transmitters right? Well one of the sticks moves up and down for throttle. All the way down is 0% all the way up is 100%. No neutral, no reverse. Now have a look at the pistol grip radios used in cars and trucks. There's neutral in the middle with reverse and forward. The pwm signal from each type of radio is basically the same, the difference is the pistol grip radio (and some twin sticks intended for surface use) have a spring to return the throttle to the middle for neutral.

Now a thumb throttle doesn't have a neutral, it's just 0-100% like an airplane throttle stick. The problem is surface esc's are programmed with a calibration sequence that is designed for having neutral and reverse. So to calibrate a surface esc to your thumb throttle you'll need to pick a spot in the thumb throttle's travel that'll be neutral. Get it calibrated and now remember that the first part of the thumb throttle's travel is now reverse/braking. Lots of esc's allow you to disable reverse (still need to calibrate for reverse/brake) so that's not a biggie but not many surface esc's allow you to disable braking. Although you probably want at least some braking (I'd probably do drag brake if anything) available unless you're going to add some other sort of brakes.

Maj_Overdrive

My Feedback: (11)

Theres been a few on YouTube with rc components. I've been tempted a few times to replicate one that used 3 large outrunner motors from Hobbyking. I think I'd rather make an ebike though to keep component cost down

karld

thanks for the extra info ill give it a go when the throttle turns up. there is no brakes on the quad bike so it would be the motors doing the braking.

RustyUs

Some Power Wheels have a single speed and some have two speeds with reverse. My daughter's Barbie Quad was only a 6v system with forward and reverse. The battery compartment had room for a 12v Pb battery and then some. So in went her PW F150 battery (12v). That doubled the speed up to about 6 mph; that was enough to scare me and my daughter as she rounded the house. Having a slight slop on either side of the house, the hard plastic tires gave way for a wild fishtailing ride going into corners . Daughter's F150 (Power Wheels) has enough room in there for a dual battery setup. That's been done before by many, and probably the easiest route if wanting just some more speed.

Just keep in mind the safety issues with hard plastic tires.

RustyUs

What kind of speed are you hoping to acheive?
I understand those who desire to modify stuff. If you got the time; patience, money, and know-how to put together a flurry of parts to make "it" happen...great! Unless you do something with the tires, you may end up with a very neat drifting machine .

http://www.modifiedpowerwheels.com
https://search.yahoo.com/yhs/search;...hspart=mozilla

rgburrill

Try this - DON'T. There are enough brain dead kids around.

Maj_Overdrive

My Feedback: (11)

Look out its the fun police! In all seriousness a kid could probably go faster on a bike than on this. Put a helmet on the kid and let them rip around on it. A kid that does some stupid stuff and learns from it is going to be smarter than one who isnt allowed to do anything.

I forget my nephews age at the time, maybe about 6, but I found a deal on a goped type vehicle. He was too young for it but he rode on the front of it with me. He didn't listen to me and did something stupid causing us to fall over on one of the first slow rides around the lawn. Just a few bumps and bruises thankfully. Since then and even now years later he listens to me about things way more and rides better than those older than him. And he's into the wrenching side of these sort of things too and is learning a lot. Or he could be like my cousin who's graduating high school this year. He wasn't really allowed to do stuff like this as his mom was fearful, overly so in my mind. So he's yet another 18yr old kid who has only driven a go kart on a rental track a few times, never been on a motorized bike or atv, barely knows how to put gas in a car let alone how it works or how to work on it. And he didn't have any real interest in getting his drivers license, let alone driving well or enjoying it. Meanwhile my nephew is younger drives go karts better (too young for license), enjoys it, knows more about cars and mechanical stuff, knows just as much computer stuff, can play sports just as well. The only advantage my cousin has is he knows more sports statistics and plays video games better. Seeing how my nephew is turning out compared to my cousin I think those few bumps and bruises were worth it.

Edit: my niece is 4 years old. I took her around the lawn on my nephews mini bike for the first time when she was 2. She held onto handle bars and I put my hands on top of hers to hold her. Sure there's potential for injury, even if we were going so slow I had to basically walk it along with my feet. But she could also fall down the stairs or any any number of other things. Now the mini bike is one less thing she's afraid of even if she doesn't want to go for a ride all the time. But the times she does want to ride with me she's telling me which way to go, what bumps to hit and laughing and smiling the whole time. No bumps or bruises from it yet but if there are I think it'll still be worth it.

RustyUs

Fun Police...Hahaha.

Just use common sense, but that's asking a lot from some people. Some folks can't even stay out of trouble just walking down the street... face in their smartphones; not a care in the world. I'll let it go at that.

phmaximus

just to put it out there... no BS... NO WAY the gearbox will handle the power off a brushless motor....


I can send pics or what ever proof u need but my kids dual motor jeep... we destroyed 1x gearbox in about a month on x2 12v sealed lead acid batteries to make 24v..... then i replaced the gearbox and tried 22.2v (in the form of 2x 3s 5500mha lipos) and both gearboxes were destroyed with in a week ....

ive spent years researching solutions to the weak gearboxes..... but unfortunately there is no easy fix.

the cheapest method ive cosnidered is a second hand mobility scooter, if you could pick one up for $200, u would be laughing...just take the back end out and fit it to the powerwheels (transaxle and motor assembly)

RustyUs

Maybe cut loose (sell) the Power Wheel entirely and look into something like a X-Prowler 48v Off Road Go Kart.

The Saylors

I cant wait until the power density and toughness of the batteries on the market are enough to make an electric go kart for adults that is actually fun. I love all my gas toys but keeping them going is a pain and expensive. Charge and go has its DRAWS for sure lol sorry

shender944

I just upgraded my sons powerwheel to a 36v lithium ion battery (Hover board battery) with a 36v speed controller and hall throttle pedal. It has two 550 motors in the back so I wired them up in series until he's ready for more speed. When we are ready to upgrade ill replace the stock motors to a scooter motor with a chain drive and replace the hard plastic tires with rubber tires.