Introduction: Self Propelled Kiddo Chariot From Old Garden Wagon and Mobility Scooter on a $100 to $200 Budget.
A year or two ago, I took my two kids to the renaissance faire, and my wife and I lugged them around in this garden wagon. It was a great idea, however we had no idea how sore we'd be the next day after pulling them around for about 10 miles. So, I got the bright idea, "I've got to put a motor on this thing." We, also, now have three children who, collectively, weigh over 100lbs. There's no way I'm pulling them around again, without a motor.
I've had this garden wagon that I've used for all kinds of stuff which cost me about $89.99. I already had it and decided to re purpose it for this project, so I'm not factoring it into the cost. Otherwise, I'd say it was a $200 project, and as luck would have it, not counting the wagon, I came out under $100.
Be sure to click through all the photos. They're very descriptive and make this instructable much easier to understand. Don't forget to watch the video to see it in action.
Step 1: Canopy
Before I decided on motorizing this project, I made a canopy over the wagon. It keeps the kiddos out of the sun and protected from the rain. I used 1/2 inch OD PVC piping and various connectors and end caps. I used old tent poles to hold the canopy onto the wagon, and the whole thing is held in place with bungee cords and zip ties. The top of the canopy is made from a UV resistant vinyl tarp. I made and cut out a pattern and fastened it all together using brass grommets. It has sides that roll down, if it rains, and they roll up and are kept out of the way using spring clips. This proved to be very useful, since it rained, and we had to roll down the sides, the first time we took it out. The kiddos stayed nice and dry. The whole thing easily disassembles and rolls up in a compact package for storage and transport.
List of materials and cost.
- 1/2" X 10' schedule 40 PVC piping X 3 = $5.85
- DURA 1/2" schedule 40 PVC cap X 4 = $1.28
- DURA 1/2" schedule 40 PVC side outlet 90 degree elbow X 4 = $5.40
- Charolette Pipe 1/2" PVC schedule 40 male MPT x S adapter = $1.44
- 8' X 10' UV resistant tarp = $9.99
- Brass grommets = $2.95
Total cost $21.06.
You can probably do this project with any kind of heavy duty garden wagon and your measurements may be different from mine, but this is how I built it. I cut 4 pieces of 1/2 inch schedule 40 PVC piping into 12.5 inch pieces. These will be attached to the wagon and used to keep the canopy in place. I cut them this size, because that is exactly 1/2 inch taller than the depth of the wagon, and I wanted it to stick up just a little bit. Put end caps on these and drill a small hole in the cap for drainage. Place these cap side down in all four corners of the wagon and zip tie in place. I had some old fiberglass tent poles lying around from past failed tents. I took 4 of the loose ones, and they fit perfectly into the PVC pipe sticking up about 12 inches. This is where the canopy attaches. From there, I cut 4 pieces of PVC at 24 inches long. These are the uprights, place them on the tent poles. I put the MPT x S adapter on top and screwed a 90 degree elbow onto each one.The front and back top pieces are cut to 24" length. and the side top pieces are cut to 48" length. This makes the canopy slightly larger than the wagon's footprint and gives it a little overhang all around giving you more sun / rain coverage. This also causes the uprights to bow a little bit making it stay on the wagon better. Nothing is glued so that everything comes apart and rolls up into a nice compact package. The whole thing took up 19.8' of PVC piping, but I bought three 10' pieces, because you would have to make perfect cuts to have only 0.2' of scrap left over.
To make the canopy cover, it is best to start on a non windy day and have a helper. You can do it by yourself, but it's much easier, if you have a second set of hands. We took the tarp and laid it over the whole thing. We draped it over the wagon, so that the long side was on the long side, short side on the short side. We made sure it was square and would be long enough to cover the entire thing. We then used spring clips, to hold it in place near the bottom on all four corners. We took a sharpie and made markings where we planned to cut the tarp on the top. A yardstick helps in keeping your lines straight. We went to each corner and released the spring clip, leaving the others tied. We could then fan out the material for that corner, it should take a triangle shape. We made marks with the sharpie and yard stick leaving about a 6 inch tall triangle at the top, then one long mark tracing the long PVC upright of the canopy frame. The small triangles at the top are where I'm going to put the brass grommets. We did this on all four corners. When we laid it out to cut, it looked like a giant cross with pokey corners in the middle. We cut out the excess and put brass grommets on all four corners, In the triangle part while folding it, essentially forming a tight box that will fit over the PVC frame. These brass grommets are cheap, $2.95 for 100 at harbor freight tools and it even comes with the install kit. Here's the problem, they're a real pain in the backside to install unless you have a vice. The install kit involves smashing the two parts together with a hammer and the install kit leaves much to be desired, but if you have a vice you could simply press the two together. Once they're installed. they're there forever, unless your tarp rips. Once we had all the grommets installed, we checked the fit, and it was pretty tight. I put a bungee cord on each corner, from one of the grommets to the wagon frame, and it is secured. I roll up the sides and keep them in place using spring clips I had laying around, cost = $0, eight in total, two for each side. To roll the sides down, simply release the spring clips and use them to secure it at the bottom of the wagon. To put it away for transport, just take everything apart except what's attached to the wagon, put it all on the tarp and roll it up. I use two of the larger spring clips to hold the bundle together, but the two largest poles will stick out. It's the best I could do, to make it fit in the wagon for transport.
Step 2: Disassembly and Destruction of the Mobility Chair
A longtime friend, generously, donated the mobility scooter for the project. I did an odd job for her, at one point, and she was aware that I had been looking for one on Craigslist for $100 or less for quite some time. I was elated to get it for free. These scooters rarely go for less than $300, which was outside of my budget, and a used one from a dealer usually goes for upwards of $1000. My cost for the scooter is $0, and my friend was happy that the scooter would be re purposed to push my kiddos around. Thank you Linda! Without your kindness and generosity, this project would never have become a reality.
So, if you're wanting to do this project within the $100 to $200 budget, you're going to have to get creative. Craigslist, garage sales, estate sales, and flea markets are the best places to find inexpensive wagons and mobility scooters, which are the two main components of the project. I have seen scooters at the flea market for about $150. I have seen them on Craigslist for $100 or less, but you have to be vigilant and act fast. They go quickly at those prices. Look for ones that are in good shape but with a bad battery. The batteries can sometimes be replaced for as little as $12.50 X 2. Keep looking, and you will eventually find a scooter.
So my first thought was, "Let's take this thing apart and see what we are working with." I removed the seat, the battery and the foot plate, which exposed the scooter's interior electronics. I didn't want to modify the electronics in any way, since changing the existing circuitry could present more problems. Scooter parts are pretty expensive, if you break something you're unable to fix. After taking stock of what I had, I decided to cut off the entire front wheel assembly. I could have left it intact and just removed the console and wiring, but I figured any reduction in weight will give me more distance per charge, and removing the front wheel assembly along with the seat takes out about 10lbs. Also, it would have looked strange and awkward to have the front wheel and handlebars still attached. So, I opted to cut it off entirely. A hack saw made quick work of it, and soon the front tire assembly was off the vehicle. I still needed to utilize the console and the wiring in the handle bars, so I disassembled the entire thing to get at the parts I needed. Once the console and wiring harness were free, I could begin modifying the motor part of the scooter to propel the wagon.
Step 3: Bracket Assembly
I had to come up with a way to attach the scooter to the to the rear of the wagon. I originally wanted to use some channel iron or thick channel aluminum, but all I could get to suit my purposes at the local home improvement store was a piece of 3/4" X 1/3" angle aluminum, it was a 36" piece, cost = $6.95. I cut the aluminum to make two pieces that were the right size and I created a channel by bolting the two together facing outward leaving a gap, between the two pieces, that was large enough to fit tightly onto the wagon and still be structurally sound. I used 8X32 machine screws, bolts and lock washers = $4.95 to bolt it all together. I measured the scooter to find where the bracket needed to be on the scooter to get optimal wheel contact. Then, I drilled and bolted the bracket to the scooter then attached it to the wagon. I then drilled two holes in the wagon on both sides of where the bracket sits and put two screws there to keep the scooter from sliding from side to side. Success!
At this point, I reinstalled the foot plate and battery, plugged in the console, and tested it out. It worked pretty well, but the scooter tires would peel out if you hit the throttle too fast. So, I made sure the wagon tires were properly inflated, and I took some sand paper to the rubber of the wheels. This increased traction, but I still needed to come up with a way to engage the tires together with greater force. At first, I tried putting a bungee cord around the whole thing which was better but not enough. So, I decided on a hook and eye turnbuckle. Since the axle on the wagon is fixed and doesn't turn, this is a perfect anchor point. On the scooter, the frame at the very back provides another perfect anchor point. I attached the turnbuckle on both sides using a shackle. The turnbuckle system makes an adjustable tensioner , which allowed me to adjust the force at which the wheels come together to make the traction just right. The only problem at this point is that in reverse the scooter tries to climb off the wagon so I added two hose clamps around the bracket to hold it in place. At this point, I needed to mount the scooter's control console to the wagon handle, to be able to control speed and forward and reverse directions at the handle.
Total cost of materials
- 3/4" X 1/3" angle aluminum X 36" = $6.95.
- 8 X 32 machine screws, nuts, and lock washers = $4.95.
- 350 lb. 3/8 in. x 8 in. Stainless-Steel Hook-and-Eye Turnbuckle = $8.42
- 3/8 in. Stainless Steel Screw Pin, and Anchor Shackle X 2 @ 5.98ea. = $11.96.
- 1-3/4 in. Stainless-Steel Clamp X 2 @ $0.98ea. = $1.96.
Total cost for bracket assembly = $34.24.
Step 4: Console Modification
I had to come up with a way to get the console mounted onto the wagon handle, so that the throttle would be at your fingertips. It would not fit as-is, so I figured out where the holes needed to be and cut them out using a 1" hole saw. Remember to drill a pilot hole before using the hole saw, go slow with the hole saw, and let the drill do the work. You don't want to risk breaking the console or any of its electronics. Once I got the console mounted, my next step was to modify the wagon, so it will fit three kiddos comfortably.
Step 5: Modifying the Wagon.
In order to fit three kids aged 1 to 4 in the wagon comfortably, I had to be creative. The first time we took them in the wagon unmotorized, we simply made a big bed with a small foam mattress and some colorful sheets but the kids were a few years younger then, plus we now have the third kiddo, so that wasn't going to work. My wife and I got together and discussed several options. We talked about placing all three kids facing forward in their own seats, but we couldn't find small seats that would fit and still give them ample legroom. Couch type seating seemed like a good option, until we realized there wouldn't be a place for one or two of them to nap without making them all uncomfortable. We finally decided to use a couple of plastic milk crates we had in the garage to make seats, cost $0. We strapped two milk crates together, back to back with zip ties. We cut out one side of each of the milk crates with a hack saw and dremmel tool. Then, we put the strapped-together, cut out milk crates on the rear of the wagon. They fit perfectly, taking up only one third of the wagon's floor space. We cut out two of the screens on the sides, so that their feet can hang out the of the wagon. There was already one spot on a screen that was damaged. I wanted to remove it, anyway, so this seemed like a perfect solution. This was easily accomplished with a dremmel, or you could use a similar tool. This also makes a nice, convenient bar the kid can hang onto, like sitting in a grocery cart. Just be sure to grind or file down any rough edges, so your kiddos don't get injured. We added some seat cushions for comfort. The front 2/3's of the wagon is a large area for lounging or napping. This gave the wagon a two seat / bed combo. Any two kiddos can be in the bed at once. If two are arguing or fighting, just strap them into the back to back chairs. Problem solved! Next step, let's make it look cool!
total cost = $0.
Step 6: Paint Your Wagon!
I looked at how it was coming together, and I decided to make it look really flashy by painting the wagon the same color as the scooter. A few cans of glossy red spray paint did the trick.
2 X cans of glossy cherry red spray paint = $7.90.
Step 7: Lengthening the Wires
I needed a way to get connectivity from the console to the scooter, and the existing wiring harness was too short. I, also, wanted to have a way to disconnect the front from the back, so it could be easily disassembled for transport. I decided on trailer wiring harnesses. The wire is a thick enough gauge for my requirements, and the rubberized connectors are essentially weather proof. The scooter needed 6 wires to control everything. I ordered two sets of four pole trailer wire harnesses. They cost $18.95 including shipping. I did not use two of the poles on one side (the green wires). I cut the scooter's wiring harness in half and stripped the insulation on both ends, revealing six wires. They were color coded black, brown, red, yellow, blue and white. The trailer harnesses were color coded brown, yellow white and green X2. I wrapped orange electrical tape around the connectors of one of the harnesses and off-set them to prevent cross-connection. I used small pieces of heat shrink down the entire length of the wires to make one wiring harness. Then, I made a chart showing what gets connected to what, so I wouldn't put a wire in the wrong place.
Black trailer harness
Brown to brown
Yellow to yellow
White to white
Green terminated with heat shrink and not used.
Orange trailer harness
Brown to black
Yellow to red
White to blue
Green terminated and not used.
I soldered everything together according to the chart. Be sure to put a large piece of heat shrink tubing over both the trailer wiring harness and the scooter wiring harness, before you start. The reason I put a piece of heat-shrink tubing on the scooter side is because the wire is much smaller. This will be used to cover all the splices when you're done. Also, be sure to put small pieces of heat shrink over the individual wires before soldering to insulate your connections.
To solder the wires together, simply make a hook on both wires, link them together, and solder. Applying solder flux to the joint, prior to soldering, makes the solder flow easier but is not necessary. Be sure to clean any flux residue with alcohol, after soldering. Be sure to trim off any excess material and smooth any rough edges, before applying the heat shrink on the smaller wires. Heat the large pieces of shrink tubing over all your connections, and you're done. I then used zip ties to attach the harness to the wagon, and I ran the wires on the underside down the middle of the wagon. Be sure to leave a service loop on both the front wheels and the handle, to allow enough room for turning and steering the wagon without chafing the wires. I then soldered the trailer wiring harness to the cut end of the console wiring harness, using the same color coded chart.
Total cost $18.95.
Step 8: Wagon Riding Success.
Now that the project was complete, we decided to take it for a spin around the block. The scooter is a little slow, even at the highest speed setting, but at least you don't have to pull at all. After going around the block, about a mile, the battery showed about 1/2 capacity, so my batteries are probably on their way out. The scooter's specs list a 17 mile range at 250 lbs. the kiddos collectively weigh about 100 lbs. the seats cushions and canopy probably weighs about 20 lbs. and the wagon weighs about 50 lbs. all together we are pushing about 170lbs. We are within the specs, so my batteries are probably worn out.
In the future, I'd like to replace and/or add on more batteries to increase the range, but for now it will be used to putter around the neighborhood and for the occasional camping trip. When the kids get old enough, I'd like to modify the front of the wagon, so it can be driven while riding it. They're not ready for that, yet.
So here's the breakdown of total cost.
Total cost for The Kiddo Chariot.
- Canopy $21.06
- Bracket assembly $34.24
- Paint $7.90
- Wire $18.95
Total = $82.15.
Well within the $100 limit. I didn't add consumables like solder and heat shrink tubing as these are things I normally have on hand and don't factor into the cost. It's all about recycling and using things you have on hand to keep your cost low. If you add the cost of the wagon and what I would have paid for a suitable power scooter I go over but not by too much.
- Wagon $89.99
- Mobility scooter $100
Grand total = $269.19
I hope you like this instructable. I sure had a lot of fun making it. If you like it, subscribe and like and vote for me.
Step 9: Update
We took the kiddo chariot out on a camping trip and as it turns out I had the turnbuckle adjusted too tight. You just need to tighten it enough that it doesn't peel out. With the tension adjusted correctly the speed got better and it lasted all day and the better part of the next on a single charge! So it turns out my batteries aren't so bad after all! Check out the video above that shows a 7 year old driving it with two kiddos in it. She really isn't pulling at all and the speed is set at about half way to maximum.
Step 10: Super Awesome Update.
I added a second battery bank. This one consists of 2 ea. 12V 18Ah SLA batteries. The new batteries are wired in series to make 24V and then in parallel with the existing batteries. I put 2 ea. DPST switches inline with each battery so that they could be used or charged both independently and in parallel. Cost was somewhere around $40 including shipping.
I had a light bulb go off in my head, I realized that because I was running in reverse to go forward, it went a lot faster in reverse. I needed to flip the motor / differential assembly. This was no easy task, I had to completely disassemble the differential to do this. Now forward is forward and reverse is reverse.
The Kiddo Wagon is really fast and efficient now. the lowest speed setting is perfect for walking. Turn it up to go up hills. You could jog in front of this thing.
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