How to make an RC Power Wheels for a Disabled Child

How to make an RC Power Wheels for a Disabled Child

Meet Oliver and his power wheels jeep. Oliver is the grandson of a good friend of mine. Oliver has Cerebral Palsy, but don't let him fool you, he loves to ride around in a power wheels vehicle just like every other kid. Oliver has an issue with some spastic movements which keep him from driving the jeep himself. He likes his brother and all, but who wants to ride around with someone else when you can have your very own power wheels jeep.

Although Oliver doesn't have the control to make his jeep move around where he wants it to go, we have the technology to make is so he can ride solo and run his jeep with the rest of the neighborhood kids. To do it, Dad will be in control with an RC system. Below I will try to outline the best I can how to replicate this for yourself. I could not find any definitive directions for hooking up the electrical, what to cut out, what to put in etc. so hopefully this will help all future builders out there.

Below is a video of the Jeep finished which outlines the features put into it. If you want to see Oliver in the Jeep and his reaction, skip to the very last step. There you can watch 6 minutes of Oliver and his Family, and the excitement that ensues.

 

Note. This is not a simple lets just make this happen in a few minutes project. There are tons of electrical connections, calibrating systems, modifications etc. This is a difficult but doable project. This is my first RC power wheels and I figured it out and so can you. Cost is a bit steep for those who think this would be a fun toy for their child. The parts and supplies needed come in at right around $1000. Those are detailed in the next step.

I want to thank the guys over at Modified Power Wheels forum for their help in getting this project going. Their knowledge made it possible to pull off the build and create an awesome ride for Oliver. They were also great inspiration for some custom modifications to add the cool factor to the jeep and make Oliver's power wheels the sought after ride, because every disabled child deserves a cool ride, and not just a functional one.

Step 1: Tools and Supplies

How to make an RC Power Wheels for a Disabled Child

 

Supplies and components:

Power Wheels Tough Talkin Jeep Wrangler

Mamba Max Pro ESC - Also need to get the Castle link adapter. You get a code for a free one in the box so wait to order it.

Speed charger / maintainer

FlySky Remote Control

Inline fuse holder and you will need a 30 amp fuse

Battery Tender harness

12 v battery (extra to run components)

Firgelli Linear Actuator and LAC board Also protective controller case through link

Marine switch panel - to turn everything on and off

Servo extension cables and Male to Male you will need male/female as well as male/male

Wire stranded not solid copper: 16 gauge, 14 gauge, 12 gauge. I cut apart old extension cords missing grounds.

Wire terminal connects - Bullet, Butt, and spade connectors

----14-16 bullet

----14-16 female spade

10-12 female spade - home depot

20-22 butt connector - home depot

----14-16 heat shrink butt connector

----10-12 heat shrink butt connector

----Castle Bullet Connectors to connect to the ESC ( you seriously need these, they are soldered on)

LED lights - For headlights, tail lights, and KC lights

----Holiday Coro

----Custom Headlight / tail light set up from modified power wheels forum

stainless hose clamps - to hold actuator in place Amazon or home depot

Electrical PVC 1/2 inch - wire runs under vehicle - Home depot

2 - 90 degree elbows PVC 1/2 inch - Home depot

1/2 inch PVC mounting brackets - Home depot

Minipl8s Custom license plate laminated cardstock

Custom license plates Second Custom license plates aluminum

Wheelchair flames decal Custom Graphics

Jeep chrome emblem - Ebay

Tail lights ebay, and custom refractive plates underneath

Custom made headlight covers (heated plastic)

-------------------------------------------------------------------------------------------

Tools:

Safety glasses

Gloves

Drill

Drill bits - I used several bits from this set for clean holes through the plastic Forstner bits

Razor blade knife

Straight edge

Sharpie markers

flat head screw drivers

Fein Multimeter tool

Wire strippers

Wire crimpers

Dykes

Soldering iron

Electronic solder

Caulk Gun

Silicone caulk

Electrical tape

Shrink tubing Assorted

heat gun

torch for shrink tubing

Corrosion X for electrical component protection

Scroll saw - headlight and tail light refractive lenses.

Mounted belt sander - headlight and tail light refractor lenses.

Step 2: Un Boxing and Laying Out Components

How to make an RC Power Wheels for a Disabled Child

When you get the power wheels jeep, try to contain the excitement of assembly and don't assemble anything yet. You need to modify several of the pieces in some way or form so assembly will just hamper the end result of having to take it back apart, modify the piece and try to put it back together again.

Ensure you organize the parts you have and what pieces go with what item. Confusing the screws sent for assembly with the screws sent for the LAC board will not go over well. Organize and lay everything out before starting.

I made 9 amazon orders, 8 of which occurred after I received my first pieces in the mail due to not knowing I needed something. I also made 5 Ebay orders for specialty add ons and one trip to Home depot. I tried to cover all of the needed parts so you can make minimum orders if you like.

Step 3: Pretest Functionality

RC Power Wheels for a Disabled Child

Ensure the power wheels motors work.

This might sound silly but it isn't. If you work to build the whole thing and try out the motors just to find out you have a bad one, good luck getting a replacement after you disassembled and modified the whole jeep.

To find out if the motors work, you only have to do one thing. Install the battery.

Put the battery in the front of the jeep where it gets mounted below the plastic catch bar. Hook up the electrical connection. and push on the gas pedal. If the back wheels both spin like mad, then you are in business. If neither moves, you may have a dead battery, but the batteries normally come charged, or at least partially charged.

Once you figure out the battery works and the motors run, unhook the battery and take it out of the jeep. You are done with this for now and you can charge it if you like. The manual says to charge it for 18 hours before first use anyway.

Components

Testing several of the components is difficult as they need to be hooked up to something to function. Test what you can and the rest you will need to get further along to see functionality. The linear actuator can actually be tested with just a 9 volt battery. One polarity will push the actuator out and the opposite will pull it back (red and black wires)

Step 4: De-construction of the Jeep

wiring for a RC Power Wheels for a Disabled Child
How to do the wiring for an RC Power Wheels for a Disabled Child
wiring up an RC Power Wheels for a Disabled Child

At this point, the Jeep is wired to run off of a foot pedal in the floor. Steering is done manually though a metal rod connected to the steering wheel and under carriage bar once you install it. We are converting this to RC control so the only wires we really need left in the car are the lead wires to the motors.

Start by taking the plastic channel covering the wires out and remove the foot pedal plastic assembly. I used 2 flat head screwdrivers to release the tabs on the underside of the jeep.

Next De-assemble the foot pedal system but save all parts. We are going to use this again to turn on the roll bar and front bumper lights. Using the foot switch will give Oliver a goal to work toward some foot control to power the lights. Foot off of the pedal and they go off. Foot on the pedal and they light up.

Next take the 2 screws out holding plastic shift controller to the jeep body. De-assemble the controller by removing the remaining 6 screws. 5 are the same size. One is skinnier. I didn't have to remove the last screw as it was stripped out and pulled free.

Remove the switches and the two plastic quick connect boxes on the switches. Re-assemble the empty plastic shift controller and put it back in place with all screws. This is now not used or needed but it looks nice.

You now have all of the wires sort of bundled in the back. There are two sets of wires coming from each of the motors to the quick connect plastic white boxes. You will notice that the first set is Orange and Blue and the second is Red and Black. Should you look past the switch boxes to the foot pedal assembly, you see that the orange and red go to the front. these are the positive wire and need to be broken by a switch (aka the foot pedal) in order for the car to not move forward. They correlate with the positive wires going to the motors. Mark positive and negative on the motor wires and cut the wires at the switch boxes with a pair of dykes (diagonal cutting pliers).

Most of the other wires in these boxes are short lengths but you will find that there are two sections that are Y shaped with a common terminal plug. These can be scavenged to make a clean Y connection for the second battery to run the line to the charger and the motors. Use a small screw driver to release the wires by pressing on the release tab in the white quick connect block. I started out using these for running the motors in parallel but switched it to the battery connection instead.

Keep all of the longer lengths of wire as they will come in handy shortly. Toss the quick connect blocks and put the two switches from the shifter on a shelf for later in the project.

Next take the steering rod and grind down the metal flair outs on the top of the rod. These are about 1 inch flairs that come off the rod less than 1/4 inch. This moves the steering wheel with the wheels. We want to cut these off to disengage the steering wheel. If we remove the rod completely, the steering wheel has nothing to hold it in place. Cutting off the tabs keeps the wheel in the same spot, while not allowing it to drive anything.

The basic De-assembly of the jeep is now done.

Step 5: Lay Out of Wiring for Motor Control

How to make and wire up an RC Power Wheels for a Disabled Child
electrical wiring for a RC Power Wheels for a Disabled Child

Here was my first mistake on this build. The motors have polarity but can be hooked up either way. One way will cause the motor to run in forward, and the other in reverse. This is how your power wheels can go forward or backwards. I used the scavenged Y connectors for each set of motors putting the two positive wires together (Red and Orange) and the two negative wires (Blue and Black) together. I crimped them used the torch to heat shrink the connections and touched them to the battery. One wheel forward one wheel backwards...... Darn... Mistake Number 1.

What I did was make both motors run the same direction. What I didn't think about was that the motors are mounted facing opposite directions. Both motors were spinning the wheels clockwise, it just happened to be opposite what I needed them to do. So I cut the orange and blue wires and switched them to reverse the polarity on one motor. Now both wheels run forward.

These parallel harnesses will now power the motors the same on both sides. From here they need to be hooked up to the Mamba max pro. They attach to the red and black wires on the output wiring for the Mamba max. The white output wire is not used for a brushed forward/reverse motor set up. The Mamba max will be fielding the power from the battery and supplying it to the motors as needed. This will give speed control for slow or fast starts and stops instead of full bore power all the time. It also allows for full power to be attained from the motors as it calibrates to them. Use a 12 gauge wire for this connection and use the Castle Bullet connectors that solder in place. This will allow for the best connection as well as for you to reverse the motors direction by switching the cables should you need to later (found in the calibrating controls step).

The Mamba Max also outputs 5 volts to the RC receiver powering it through a built in BEC or power reducer. This means you have nothing plugged into the battery port on the receiver. This does it for you. Should you plug in an RC servo extension to the battery port, you may overload the system so don't do it.

The Mamba max will be routed through an inline fuse (25 to 30 amp) on the positive lead to ensure there are no issues with electrical shock or shorting out. The after market batteries do not have a fuse built in. The motors will be run on the after market battery as it is slightly longer lasting at 12AH vs the 9.5AH of the original battery. An original power wheels battery does have a built in fuse. So the rest of the components are ok without inline fuses although I am using a breaker box just in case.

We will get to that....

Step 6: Installing the Control Panel

control panel for an  RC Power Wheels
control panel for an  RC Power Wheels
control panel for an  RC Power Wheels

In order to make this into an easy on off system with control over what comes on and what doesn't, I purchased a 4 switch control panel. The control panel has built in circuit breakers which are set at 10 amps each. The whole thing is designed for marine applications so it is fairly waterproof on the surface. The back, where the wire connections are, needs to be protected.

This panel is going to run the charger for the power wheels battery, the LED lights, the Linear actuator, and the foot pedal lights. The motors will be on separate switches.

The panel is run in parallel with all of the switches and breakers on one main positive and negative in. I cut the parallel lines to the 1st breaker/ switch and added it's own positive and negative leads. This was done because originally, I was going to run both batteries off of this control panel. After thinking through the project, I found I wanted a separate on off switch for each charger so I needed two extra switches. As such, the control panel went back to just one battery. Had I sorted this out sooner, I could have left the common negative attached and just separated the Positive wire off of the first circuit. Hindsight is always 20/20....

This allows me to run the charger off of one terminal, and everything else off of the parallel system. This should keep the charger from slowly pulling a charge from the battery when not in use as I can turn it off.

It isn't the smallest panel in the world and I needed a flat 6x6 surface to mount it on. I chose to use the back of the seat as the seat is molded hollow plastic. This allows for access to the wiring to fix an issue should one arise, as well as protection from the elements for the wiring as rain will not be able to get in due to the one piece molded plastic.

A hole was cut into the back of the seat using a razor blade carefully in several passes. The plastic is thick and will not cut with just one pass. The back of the panel was then lined with a layer of silicone caulk. It was then screwed into place and the silicone excess wiped off and all edges sealed.

I labeled the switches to charger, Running lights, Pedal, and 12 Volts

Charger is separated from the others and will be off when normally running the power wheels. When it is on everything else can be switched off saving the systems from an over charged power spike. It is also separated to keep power from running back into the charger. You notice this when you turn the charger switch on without it plugged in, and it lights up red, then you turn it off and it slow fades out because energy is Flowing to the charger and is slowly draining the battery.

Running lights will be the headlights and tail lights.

Pedal is the roll bar lights and front bumper lights

Power 12v is the actuator / LAC board which runs the steering

Step 7: Mounting the Linear Actuator

mounting an actuator to an  RC Power Wheels
mounting an actuator to an  RC Power Wheels
using a linear actuator in an  RC Power Wheels

The actuator needs to be mounted somewhere around the front wheels to push and pull the steering bar which in turn moves the direction of the wheels. I cut out a few plastic tab supports and fit the actuator under the steering bar. Prior to fitting in the actuator a 3/4 inch hole was drilled where the wires feed off the back of actuator and into the battery compartment above.

I wedged some wood blocks around the actuator base to help reduce
movement by giving static surfaces to push against. The actuator was secured into place with silicone caulk to help weatherproof a bit, and then strapped in with adjustable stainless steel hose ring clamps, which wrapped the actuator and fed through the battery compartment above. A piece of PVC was added to allow the straps to tighten enough around the actuator without bending on hard angles and losing strength. This process will keep the actuator from moving out of place when force is applied.

The stainless bolt in the next paragraph failed. Don't do it this way.

I drilled a hole through the bar and added in a stainless steel bolt and lock nut to connect the two. The actuator cylinder was slightly off center by about 3/8th an inch of the bar. I angled the bolt through the bar and managed to feed it through. There was some torque on the bar but it seemed to settle out. This will move the bar back and forth for steering with a little bit of play. This worked for 4 hours of testing.

*****After that, the stainless bolt sheered. *****

Turns out, just because something is stainless, doesn't mean it has a high tensile strength. I decided I didn't want to have anything like this happen again. I can't just fix it when it is in another state is something like this occurs again. I had to figure out a better attachment method for the cylinder from the actuator to the steering bar.

I cut a door hinge in half with the dremel tool. I straightened up the cylinder underneath, taking away the angle from before, and figured out where to drill an offset hole in the hinge. I used a Grade 5 bolt from the actuator to the hinge, and a grade 8 bolt through the steering bar/hinge. All grade 8 nuts / lock washers were used to connect it all together. The hinge wanted to rotate a bit with the torque so I added a self tapping metal screw through the hinge/bar to secure it in place and take the twist away. The screw was then cut flush with the back of the bar with a dremel cut off wheel to make sure it didn't catch anything underneath.

Here is a quick video on the steering.

There is no longer play in the steering when it moves. It is smooth and moves right away when you turn the controller wheel. This should last a long time without sheering issues. The beeping in the video is actually the actuator, not the LAC board. It is trying to find it's center point and with a load on it, beeps until is micro adjusts to the right point. So pretty much every time you move the cylinder, it will beep following.

Step 8: Wiring the LAC Board

using a controller and a  linear actuator in an  RC Power Wheels
using a linear actuator in an  RC Power Wheels
linear actuator wiring in an  RC Power Wheels

The wiring for the LAC board is easy but not straight forward. 

You will need all wires, a total of 5 from the Actuator, 2 from the battery, and one RC male connector to wire properly. See picture below of a finished wire LAC board. I combined 3 pictures from the Configuration sheet together to show you what it should look like, except the white and blue are reversed (as explained below). My wiring set up is the same but I used a white wire vs red for power so to avoid confusion, I made the picture instead.

Below the process of what is what is spelled out.

To begin, the LAC board is set up to run with several types of controllers. We are using RC but powering off of a 12 volt battery. The power from the RC Receiver is only outputting 4.5 volts. This would not properly power the LAC board to the power we need for the actuator. To fix this, we run separate wires to the + and - on the X6 port. (refer to the data sheet) Do not have the wires connected to the battery yet. If you do and the board touches something metal or electrical conductive, it will short out and you just lost your LAC board.

Now with the power running the board through X6, if you left the RC cable just as is, you would then be adding another 4.5 volts of energy, and as such, fry the board. To solve this, you must cut the center wire of the RC cable. This will either be red or orange. The white and black or yellow and brown, depending on the cable, will do the RC part. The Red or orange is just the power. Do not have the RC receiver powered yet.

Ok, so now hook up the cut RC adapter with the black to the - and the white to the RC on port X3 (refer to the data sheet)

Next you need to hook up the 5 wires from the 2 wire leads of the Actuator. You will have red, black, blue, yellow, and white. These hook to the X4 ports. (refer to the data sheet). They are white to P+, yellow to P, Red to M+, Black to M-, and Blue to P-. I listed them here in order from top to bottom. The data sheet has them listed in this order as well. The picture from the compilation of the configuration sheet has the blue and white reversed. This is from their data sheet but it is wrong. They list how to wire correctly they just show it backwards. Make sure the white and blue are in the right spots.

There are several adjustments that need made. We will cover those in the calibration step. Don't adjust anything now. Seriously, don't do it or the actuator may not move at all.

Because the LAC board is wired in the front battery compartment but the Receiver for the RC controls is in the back compartment, I needed to run a lead between the two. I found a bunch of RC servo extension cables on Amazon for a few dollars. I chained these together and used a heat shrink tube over the connections to shrink down and hold them in place. It worked flawlessly. I did not cut the red wire out of all of the connections as I only really needed it cut out of the first one. The rest will just be dead but will help with the strength of the cable as it runs the length of the car through some cable chases made of PVC.

You will need male to female connections but at the receiver end and the LAC board end, both are male connections, so you will also need one Male to Male servo extension as well. Link in materials step.

Step 9: Tying Into the RC Controls

remote control wiring in an  RC Power Wheels
remote control wiring in an  RC Power Wheels
This is rather simple really. You have a small receiver from the Flysky control system. This has an antennae on it which is important to garner the proper signal from a distance. I drilled a hole in the side of the seat and ran the antennae through it. I silicone caulked the antennae support in place and also the receiver on the inside of the seat. The silicone peeled off so I used a piece of strap instead with some screws.

There are 4 ports on the receiver. One for battery and 3 for channels. For this project we only need to use two of the ports. The battery and Channel 3 ports (the top two ports) are left unused. How is that you say, no battery? Let me explain.

An excerpt from the Castle Mamba Max Pro ESC says:

Your Castle ESC plugs into the throttle channel of your receiver. This is usually channel 2. Your Castle ESC provides 5 volts to the receiver to power the receiver and the steering servo. No separate receiver battery is needed to power the radio system.

What this means is the Mamba Max ESC contains what is called a BEC, or a Battery Eliminator Circuit. That means that the ESC takes in the 12 volt battery and outputs 5 volts through the RC connector. This powers the Receiver when plugged in, at a level that will not hurt the receiver. If you purchased a separate BEC and plugged it in, you would be providing too much power to the system and could hurt or fry the whole thing.

So Plug in your RC port from the Mamba Max ESC to the receiver in Channel 2. This will control the forward and reverse. Make sure you have it in the correct orientation for + and - The brown wire is the - and the yellow is the RC, the red center is +

Next plug in the RC connector you ran from the front compartment that hooks into the LAC board into channel 1. Black is - here and white is the RC. This will control the steering left and right. And that is it. You are tied into the RC controls. They still need calibrated with the LAC board and Mamba max in the calibration step

Step 10: Wiring Up the Power Wheels Battery

remote control wiring diagram in an  RC Power Wheels
Oliver on Slide
underneath an RC Power Wheels
The original power wheels battery is mounted in the front battery compartment of the Jeep. This battery is 12 volt and 9AH. The 9AH is basically like the gas tank. The second battery is 12AH meaning it should run longer. Increasing the AH on your power wheel to an extreme amount can cause the motors to burn out prematurely. Some people like to run the batteries in parallel which keeps the voltage at 12 but ups the AH to 21 or even higher if they add more batteries. Although this works out and makes for a much longer run time, it can overdo the system and cause the things to short out or shorten the lifespan. For that reason, I chose to not run the batteries in parallel and instead keep them separate for their functions. The original power wheel battery is going to run the Linear actuator, the Headlights and tail lights, and the Rollbar and bumper lights. It will outlast the second battery before it needs recharged maybe even two or three times as long or longer as those accessories pull much less power.

Before beginning the wiring, go outside, to a park, play with your kids. Whatever you like. You will need a clear head and your family would like to see you again. Ok, on to the wiring.

To wire up the battery I need to run it back to the rear compartment which is where the controls and switches lie. The two 14 gauge leads were kept attached to the original battery connector and extension 12 gauge wire was added with heat shrink butt connectors and run through the underneath cable runs of PVC. Do not have this plugged into the battery during any part of this step.

From here the wire has to be split. The wire leads to two separate connectors for each the Positive and negative control panel leads as well as going to the battery. The negative side is run to a grounding bar which allows for multiple wires to be tied together without a ton of crimp connections.

The top separate control panel switch will connect a positive and negative wire to the Power Wheels charger we are splicing in. The negative only goes to the control panel to complete the circuit to light up the LED and let you know it is on or off. This negative will be spliced with the negative leading to the grounding bar and then to the battery. The other 3 switches on the control panel also lead to the grounding bar. As I explained earlier, in hindsight, I didn't have to cut the negative bar on the back of the panel with how I am now wiring it. Originally I was going to have both batteries run through the single control panel which is why I cut the negative lead. With how it is wired in the final configuration, it could have been left connected. Regardless that is what it is now.

The top switch will run the charger. This switch is connected with the common negative wire which leads from the grounding bar (basically a connection bar for a bunch of ground wires to lead to the battery) to light up the LED. The positive wire leads out of each side of the switch. These will be from the positive side of the Power wheels battery charger split and run to either side of the switch. This will allow for an on/off of the charger to keep from draining the battery slowly.

The Second switch runs the headlights and tail lights. The positive wire from the headlight wire bundle will lead to the switch. The positive is already powered through the main lead in the control panel. The negative side of the headlight wire bundle will be spliced into the negative lead at the grounding bar.

The Third switch runs the Pedal lights which are the roll bar lights and the bumper lights. The positive wire from the pedal foot switch will lead to the pedal control switch in the control panel. The other wire from the foot switch connects to the positive on the lights. The positive is already powered through the main lead in the control panel. The negative side of the pedal wire bundle will be spliced into the negative lead at the grounding bar.

The Fourth switch runs the Linear actuator and LAC board. The positive wire is in place in the control panel so the positive lead from the LAC board is wired to the switch. The negative wire from the LAC switch is spliced into the negative lead at the grounding bar.

I am not very good at drawing out electrical components as I am not proficient on terminology in a set of electrical prints but here is my best shot. I have separated out the components run off of each battery and where they should tie into. I hope I don't confuse anyone with the non electrical drawing of electrical components :0)

*****The pedal foot switch was wired up like it was when we started tearing apart the car. Instead of it running the motors though, it is spliced into the positive lead for the running lights. This makes a switch for Oliver to push with his foot to power those lights. It is an action / reward system. He has a reason to try and push the pedal down and make the lights light up. That will push him to work to use his legs better and gain some muscle control, at least in theory. If something happens and Oliver cannot gain the ability to push the pedals, there are bullet connectors in the wire leads to unhook and hook the leads together avoiding the pedal switch which will allow for the running lights to come on with the pedal control switch is turned on. *****

Step 11: Installation of the Second Battery

electrical wiring diagram in an  RC Power Wheels
electrical wiring in an  RC Power Wheels
electrical wiring in an  RC Power Wheels
electrical wiring diagram panel in an  RC Power Wheels

The original power wheels battery came with a built in fuse. If you were to take the top off of the battery (which is actually a false top) you would see a sealed fuse encased in the battery with the sealed battery below it.

Most after market batteries do not have this fuse. Since I am no longer putting the power of the battery through a Circuit breaker before it gets to my systems, I need to add in an inline fuse for that. The motors will have an inline fuse at 30 amps to keep the electronics safe there as well. I am also installing an onboard charging system called a Schumacher 300 to charge the battery. Because of this, I purchased the battery tender with a built in 7.5 amp fuse to keep any issues from arising with the charger and battery.

The battery charger puts out 3 Amps. The second battery is a 12AH battery. This means that to charge it correctly, you need to charge at no more than 25 percent of the AH, or 3amps. This is right at the 25 percent AH limit of the battery for safe charging. This is too much for the original power wheels battery. The normal wall charger which puts out 1.5Amps will need to be used for the original battery as it is only a 9.5AH battery. If you try to wire this to both batteries at once, you likely just created a parallel system and now you have 12 volts at 21.5AH and will hurt the system. Don't do it.

The battery charger was spliced into the main lines on the battery. The positive lead for the charger was split and run to one of the switches we scavenged out of the shifter box. This way when not in use, it can be turned off and will keep the battery from running down by back flowing into the charger. With the built in charger, this will allow for a charge when needed. The second switch from the shifter was used to turn the motors and ESC on and off. It will be turned off when charging so no power will ever reach the motors or the ESC while the battery is charging. This makes for a simple charging process. There are no cables to remove or batteries to take out. Just turn the system to off with the switch, turn the charger switch on, and plug in the charger. I added some green LEDs next to the switches that turn on with the switches as indicator lights.

To wire, I made another drawing. This one is simpler than the first. Hopefully it makes sense. I am sure electrical engineers are rolling in their graves right now.

Step 12: Headlights

headlights in an  RC Power Wheels
headlights wiring diagram in an  RC Power Wheels

LED lights
A custom LED lighting kit was purchased through a member of the Modified Power Wheels forum. You can access the page HERE if you want to order a kit for your Power Wheels as well. The kit cost 35 dollars with shipping.

The kit includes 2 round discs for headlights, and 2 sets of 2 LED strips with 3 LEDs in each one. You can order red or white for the tail lights. They are all pre wired with 6 inch leads off of them and heat shrink tubing. There was an under-lighting set of LEDs as well, but after installing the headlights and tail lights, the under lighting kit just didn't seem right with the build. I will be using those lights for a part of a prop for Halloween, the Gru ray player from Despicable me 2.

The Power Wheels Jeep comes with stickers for headlight and tail lights. Because of this I needed to make lenses for the head lights.

I recycled or re-purposed some plastic that used to be in an over head Florescent fixture. This diffused the light in the fixture and it will now defuse the light for the LEDs. The pocket for the headlights is 3 1/4 inches diameter. I traced a candle lid that was 3 1/4 inches on the plastic with a sharpie and cut it out with a scroll saw. Using rubbing alcohol and a paper towel removes the ring of sharpie that was left.

The circle was then set on top of a mason jar and heated with a heat gun. This made the plastic pliable. I formed the plastic circle down on to the mason jar and used an empty tuna can to help push it down on the jar evenly. The first one came out amazing. It was exactly perfect in my mind. It had a nice dome shape, was still clear, and fit like a glove in the spot for the headlight.

Tries 2 through 6 were miserable failures. The plastic heated too much and turned white, or the plastic shifted off center and bent funny or one way vs another. For the life of me I couldn't get it to repeat what I had just done. Several times, I looked at the first one and wondered how in the world I did that just 30 minutes ago. Try 7 was close enough that I went with it. The first was still the best by far. If I had to do this again I would need to re-think this process.

After forming the lenses, a hole was drilled center of the headlight base. The headlight was put in place, sealed with silicone and a silicone ring was made around the perimeter of the headlight opening. The lens was pushed into the silicone ring to seal it to the Jeep and keep water out of the LED inside.

The two lights were connected with wires and run through the PVC chase under the Jeep to the back compartment where it was connected to the control panel.

Step 13: Tail Lights

tail lights in an  RC Power Wheels

The tail lights on the Jeep were also stickers. There were no lenses or even recesses like the headlights had. Because of this I needed a lens to work with. I found a supplier on Ebay of trailer tail lights. I purchased two of the lights, Grote 91962 model which were just about perfect size for what I wanted. They have no screw mounts as they snap in place on whatever model trailer they would have gone on.

When I put the LEDs behind them, the plastic was too clear for me. I could see the outline of the LEDs and the light wasn't diffused at all. I cut some of the refractive plastic I had left from the headlight lenses to fit up inside of the covers. The plastic diffuses the light and makes it look better in my opinion. The plastic was silicone sealed in place.

A hole was drilled under where the light would attach and the LEDs mounted with the 3M sticky backing. I tried and failed to use silicone for the adhesive to the Jeep as it didn't want to stick well enough. I ended up drilling a hole through the cover and using a stainless steel screw to hold the light cover in place. Silicone was then used to seal the cover to the jeep.

The wire leads were connected to each other inside the battery compartment and run to the control box. The extension wire connecting the lights were connected using heat shrink Butt connectors to ensure a solid sealed connection from the elements.

Step 14: Roll Bar and Bumper Lights

flood lights in an rc power wheels jeep
roll bar lights in a power wheels jeep

Headlight Wiring Schematic

I also added in 4 sets of LED lights to the Roll bar and front bumper to light up the Orange covers. These lights were left over from some LED floods I built for Halloween. Two rows of lights, 6 RGB LEDs each containing 3 individual LEDs in total were put into each light. This helped with brightness to shine through the plastic covers. Holes were drilled to run wires. wires were shrink tubing sealed over crimp connections. The wires were run through the roll cage system and connected to the original throttle pedal as an on/off switch. This way Oliver has a goal to push the pedal down to light up the system. Goals are important for a child with Cerebral Palsy to gain a reason behind pushing themselves to do better. This set of lights and the pedal is on it's own separate switch in the control panel.

I made a mistake when putting these together. The hole I used in the back of the light for the bumper lights was designed for a long screw to attach with a spacer to the frame of the jeep for stability. Since I had already assembled the lights and put silicone to seal them, I drilled a second hole below the first one to mount the support screws. I suggest drilling a second hole to start with and run your wires through that hole instead.

Step 15: Pedal Switch

Pedal Switch

The Pedal switch is what used to make the motors turn. The original set up had the motors running when the pedal was pushed. Since the motors are now run off of RC this pedal is not important to the functionality of the Jeep. But....

I wanted to create a system of Action / Reward for Oliver to help him work toward more leg control. If Oliver could push the pedal down, the lights on the roll bar and front bumper would light up. I split the line going to the control box for the pedal lights, and ran the positive to the pedal first. This basically put a light switch in the center of the positive wire and the lights only come on when the pedal is depressed.

On the back of the pedal there are 3 prongs sticking out. You need the two that are shown in the picture to make a connection. Use Female spade connectors to attach to the switch. Depress the pedal and make sure it does what it is supposed to and then put the pedal assembly back into the Jeep.

The wires leading up to the pedal have a set of bullet connectors on each one, but opposite each other so if I need to eliminate the pedal switch, I just disconnect them and connect the wires together vs through the switch and they would be on any time the control panel switch is. Hopefully we never have to do that and Oliver gains the leg control to push the pedal.

Step 16: Calibrating Controls

Calibrating Controls remote control for RC power wheels jeep

There are three things that need calibrated to control the power wheel vehicle. You have the steering which is controlled with the linear actuator and calibrated through the LAC board, and you have the Forward, reverse, braking, which is controlled through the Mamba Max ESC. You also have the RC controller which controls the final calibration of the LAC and ESC

LAC board calibration:

On the LAC board there are several adjustment dials to get the optimum throw and control to the steering. Below are two links to help. The LAC board comes with no instructions. These links will tell you a ton of things that are not important to you and a few things that are important.

Datasheet

Configuration

There are 4 adjustments that can be made by turning one of the 4 potentiometers. The Speed, the Accuracy, the Left limit and the Right limit. What I didn't know is you can't adjust them actively with the power on to see what happens. The changes take effect only when the power is turned off for a minute or two and it resets. I played with the 4 potentiometers and couldn't get anything to happen. So I figured there wasn't much difference in what they did when I turned them left or right so I found the approx. center point and set them all there. When I came back down to try out the RC controller I had calibrated, the actuator didn't move.

I spent the next 2 hours trying to figure out why. If I didn't have a buzz cut, I would have pulled all my hair out. Luckily I couldn't get a grip on more than 2 at a time and that is just tedious. I unplugged wires, made the actuator move with a 9 volt battery to ensure it wasn't bound, analyzed the LED light and how it got brighter if I was using the RC controller, figured out I could remove the blue or white wire to get the actuator to move left or right, but I couldn't get the darn thing to work with the remote control. I even sent an email to tech support. They don't have a 24 hour tech chat. I finally found the configuration sheets above with the help of google. I found my answer.

Limits – The Potentiometer closer to the USB connector is the retract limit, and the one further away is the extend limit. For maximum stroke, set each potentiometer to fully clockwise. Rotating counter clockwise from this position will move the limits inward, from either end. If your settings overlap, the actuator will not move at all. Bingo

When I moved the potentiometers to center, I told the right and left limits to intersect. That meant that I was telling it not to move any direction. Because it took a minute or two for things to reset properly, when I unplugged wires and turned everything Counter clockwise, then Clockwise, nothing happened because remaining power kept the settings the same. Once I sorted out what was the issue I was able to solve it and it started working again.

Now I say all that to tell you one thing. Turn all of the limits to the right or Clockwise. This will bring the accuracy all the way up which actually makes the cylinder move smoother, the speed to max, and open the limits completely. Now you only want to adjust the speed back down. Turn it right and left to sort out the distance it can turn less than 360 degrees on mine. Then turn it all the way Clockwise and back down Counter clockwise about 1/3 of the max or 90 degrees on my potentiometer. If the speed is all the way to max the movements left and right are too jerky and quick and you can't steer and make minor adjustments back to straight without weaving back and forth sharply. It is just too hard to drive at max cylinder speed. You want a smooth ride for the child inside.

Then put the panel in the protective box and leave it be. For the love of Pete, Don't touch it again. Your RC controller will limit what you need without messing with the board.

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ESC Calibration:

The Mamba Max Pro ESC is designed for a brushless motor right out the box. A power wheels vehicle has Brushed motors. This means, out of the box, the Mamba Max will not power the wheels properly.

To fix this, you must change the settings on the Mamba Max Pro. There are two ways to do this. First you can use a computer and the Castle Link adapter, or you can use the field card adapter.

The Castle link program is free and you download it to a PC, or a Mac in a compatibility mode.

The Castle link adapter brings your RC connection to a mini USB port. You then plug the USB into your computer and make the adjustments. This is free with free shipping with the code in the box. It will take up to 2 weeks if you live in the US to get the adapter. I got mine in 3 days.

The field card allows you to make all the adjustments needed without the need of a PC. You get a discounted card with free shipping for 10 dollars using the code in the box. I went this route as I have a Mac at home.

Once you have the card, You need to hook up the Mamba Max RC cord to the card and have the Mamba Max powered.

The card has a ton of settings on the front and is a push button adjustment system. You push the one button in the bottom right corner to move between settings and hold the button to adjust the settings.

You need to set several of the adjustments to get the ESC to work with the brushed motors properly. To start, plug in the field card, then turn on the power to the ESC. It will then go into calibration mode.

You adjust:

Brake/reverse type: Setting 3 forward, brake, reverse
Brake amount: Setting 2 -- 50 percent power
Reverse amount: Setting 2-- 50 percent power
Punch traction control: Setting 4 lowest
dead brake: Setting 2 drag brake 10%
drag band: Setting 2 normal
motor timing: setting 2 normal
motor type: Brushed reversing
Cut off voltage: 5v

This will set up your system to run the power wheels motors properly and give you the control you need to move forward and backwards with ease. Once set, turn off the power, then unplug the card. You are not done yet, you still have to pair the remote control to the ESC - shown below.

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RC controller

The Flysky controller and receiver I purchased is highly customizable. You can adjust the trim (how far the actuator turns left or right), you can adjust the limits on the speed of the motors, and you can program in several different receivers as well.

Watch this video for instructions on how to program the remote Programming a FLYSKY remote. It explains it much better than words can. I will list what to change and why below.

Channel 1 is the tire looking knob. It controls left and right. If you go to the REV function you can reverse the controls if you like if you feel left or right should be the opposite turn of the knob than what it is.

Channel 1 You need to adjust the endpoints. This will keep the actuator from pushing or pulling too much and binding the wheels into the wheel wells. To adjust this go to the E adjustment and choose channel 1. turning the tire knob will switch left and right end points. set each end point to between 60 and 70. Your end points may be different depending on how you put the linear actuator below, but you will definitely not need the full 2 inch extension of the actuator.

Channel 2: Reversing controls- At least on my Mamba Max ESC, the controls are reversed for Forward and reverse. When I pull back on the trigger it should go forward but it goes in reverse. This really threw me off when I was trying to calibrate the Mamba max. Switch this to reverse using the REV function and channel 2.

The rest of the settings should remain at either 100 percent where they started or on the NOO setting which is where some start other settings start.

___________________________________________________________________________

Pairing the RC controller to the Mamba Max.

If you reversed the channel 2 setting this should be simple. If you didn't then it may take you a while like it took me. Pairing the controller will give you the max potential of your motors. It may work without pairing but the controller will not know the limits of the motors and they will not function to full capacity.

Steps to do this are listed in the Drivers ed manual of the Mamba Max on page 14-16. Read through this to understand what it does and why. If done right it takes 15 seconds. So read below, understand what you need to do, do it quickly, and it will calibrate right.

Remember, read first, remember the order, then do it. Don't read as you go.

1. Turn on the controller. Once on, hold down the trigger which is full power forward.

2. Turn on the Mamba Max. It will give you a series of tones. A few seconds later it will give you 4 rings or tones meaning it is done calibrating the forward.

3. Now push the trigger all the way to full reverse. Now you get 4 more tones. Let go of the trigger

4. It will ring again 4 times and then a few seconds later give you a different 2 tone ring. when you hear the 2 tones you can now move forward and reverse using the RC controller.

At this point you find out if you have the motors switched for what the ESC thinks is forward and reverse. If you do, switch the wires from the motors using the Castle bullet connectors. I had to switch the wires in my build.

Ok again, procedure is hold down, push forward, take finger off trigger, after each series of tones. and you are done. Now read it again and then try it out. If you mess it up like I did 7 times in a row, as long as you are holding down or pushing forward the trigger when you turn on the ESC, it will calibrate. Once I figured out the reverse controller setting, it calibrated right away with no problems.

That said if later on you start up the ESC with the trigger held it will try and calibrate again. Just remember to turn the ESC on before you turn on the remote.

Step 17: Weather Proofing Connections and Terminals

Calibrating Controls remote control for RC power wheels jeep

Silicone is your best friend here. Where ever I could, I put silicone around connections or holes in the Jeep I made. Trying to keep out as much water as possible is what I was going for. But silicone does not stick well to the plastic of the Jeep. So don't use it to permanently adhere pieces or you will be disappointed. It does seal out water well, but it does not bear weight well and hold it's seal.

The headlights and tail lights were mounted with the help of silicone to keep water from the LED electronics inside. The holes through the body of the jeep where wires were run were sealed with silicone. The Control panel was sealed to the seat with Silicone as well. Anywhere that I could add protection to the components I did.

The internal connections were connected with heat shrink connectors where possible to seal to the wire. Heat shrink tubing was also added places where the connectors could not be heat shrink activated. Sealing out moisture and preventing corrosion is key to long life of the components inside.

The open connections were sprayed with Corrosion X, which is an inhibitor for corrosion and water intrusion. it dries clear and protects open components like the connection points on the control panel and switches. It is a mist/ spray when applying so keep the battery connections turned off just in case. Let dry for an hour or so before turning everything back on as the spray is flammable.

Step 18: Adding Character and Flair

back end of a rc power wheels jeep for disabled child

The Power Wheels Jeep came much cheaper than I thought it would as far as accessories. Most everything is stickers you place where you want. That includes Headlights, tail lights, reflectors, mirrors, the Jeep logo, and the fancy paint flair.

I set out to fix that the best I could. You have already seen the steps on the headlights, tail lights, and roll cage lighting. Here are a few other things I improved.

Mirrors: I purchased a mirror repair kit that you cut out and glue in place. I placed the original sticker mirrors on the repair kit, and cut them out with a razor blade to replicate their size exactly. These were then added to the Jeep with the sticky tape they came with. There is now a reflection that you can see vs a picture of a mountain in the background. This will also help Oliver see the lights lighting up behind him with the foot pedal switch. Or see his brother he left in the dust.....

Jeep Emblem: The Jeep emblem was a sticker with a whole bunch of trademark stuff written under it. I found a supplier on Ebay that sells Jeep Chromed plastic emblems. There are hundreds to choose from. I found one at a price I liked with free shipping and bought it. It now adorns the back of the Jeep.

License plate:

The license plate was ordered from a site called Minipl8s. They have a ton of sizes and designs for plate, personalized for each state and going back 30 plus years for license plate styles. I chose the Ohio plate, which is where I thought Oliver lives, and the Kids First design as it fits best with a Kids vehicle. It is a printed plate on a thick paper and is laminated. It comes with sticky back Velcro to mount it.

After ordering the license plate, I found out that Oliver didn't live in Ohio close to his grand parents. He lives in Virginia. My mistake. I needed a new license plate. The Modified Power Wheels forum has a member who prints custom plates on aluminum for about the same price as the MiniPl8s. He has to design the plates or you can get him your graphics. They are not completely accurate to the state plates but close enough that I liked the result. The new plates are slightly bigger and were planned to go front and back of Oliver's jeep. The front plate just didn't fit right between the lights so I am giving it to Oliver to put on his wheelchair instead.

Custom Graphics

You can use the stock graphics they provide but this is a modified power wheel. You need awesome graphics to let people know that this is not just a toy, but a real means of Oliver getting around and playing with friends. I found a ton of graphics to choose from and went with the Wheelchair flames design because Oliver is no longer just stuck being pushed in a wheel chair.

Step 19: 5 Point Harness

seat harness for disabled child
seat harness for disabled child
seat harness for disabled child

As Oliver has limited body control and the spastic movements, I didn't want him sliding out of the jeep when flying down the sidewalk or while off roading.

I purchased a 4 point adult racing harness on Ebay. This harness was cut down to fit the jeep and a child's size. It attaches to the Jeep with some bolts and washers.

I made a 5th point for the harness that the seat belt buckle goes through. This way the 5 point harness is achieved and the rider (Oliver) will be safe and upright in position at all times.

Step 20: Finished Product and Testing

How to make an RC Power Wheels for a Disabled Child
seat harness for disabled child for power wheels jeep
seat harness for disabled child for power wheels jeep

Here are some pictures of the finished product. The whole Jeep over all looks stock if you didn't know what it was supposed to look like. There are not wires or crazy pieces everywhere that do not belong on a Jeep exposed. If you didn't see the back of the seat with the control panel, you would assume you just jump in and push the pedal and go.

Product testing here was also very important. Since this Jeep is getting sent to Virginia from Ohio, I wanted to make sure it worked the moment they took it out of the car. I tested it several nights in a row, a few with my 11 month old son riding around in it. Other nights with a sandbag for weight. Working out the bugs was what the testing accomplished.

Here is a video of the early testing with my 11 month old hanging on for the ride. He never fell or lost balance and now crawls toward and pulls himself up on the Jeep in our living room as I am finishing it up. I think he wants one.

I found that I needed the second battery more secure. It slide left and right in the strap I had it in, and the terminal on the negative side came loose, in turn killing the movement of the Jeep. I fixed this with a PVC spacer and some electrical tape on the terminal wires to the battery to keep it a bit more secure.

I also found an issue with the Actuator that would cause it to jam or shut off for about 10 seconds and reset itself. This normally happened with prolonged turning in one direction and the Actuator seemed to have a built in safe mechanism to self protect. With some adjustments down in speed on the LAC board and the adjustments to the end points on the controller, this seems to have sorted itself out for the most part.

Speed on the Actuator was worked out here too. I couldn't drive in a straight line making small adjustments to save my life. The actuator was too fast and would swerve wildly back and forth. That was sorted in the calibration section of the LAC board in this article

As addressed in the Linear actuator section, I had the connecting bolt sheer. This had to be re-engineered to a stronger system. It failed after 4 hours of testing, and my wife thought I was just driving it for fun.... well it may have been partially that too.

I also had to sort out a start up procedure. Sometimes the Radio control would not connect with the ESC and motors if the LAC was started first. The ESC thought it was supposed to go into Calibration mode but never did and it just revved up and did nothing. Turning on the ESC first, then the three control panel switches and then the remote made everything work consistently. In the end I would turn on the remote first, then the ESC and then the 3 switches, all within about 4 seconds. Never had an issue when everything was turned on fast.

Testing was also important to run the batteries down so I could test out my inline built in chargers. Both chargers seem to work out great and I am glad there is no longer a need to unplug and remove batteries from the Jeep.

Step 21: Oliver's Jeep
oliver in his power wheels jeep

The Jeep was delivered to Oliver's family on Easter Sunday. On May 3rd, they were able to drive down and deliver the jeep to Oliver. I put together a 6 minute video of Oliver's first reactions to the Jeep, and some video of him playing with his brother Andrew.

Oliver has never been able to play along with his brother so their tag session in the Power Wheels was the first time they were ever able to play like this. Oliver, was asked what he thought of the jeep, and he signed love. It was a wonderful honor getting to give him the gift of mobility.

Some of the video looks like it was taken with a toaster. The cell phone video was a bit grainy, but overall, you can still see the enjoyment Oliver is having with his family. I apologize in advance for select sections of video quality, but you can't repeat the first moments, so here they are in all of their blurry and sometimes clear glory.

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