Intro: Electric Trike
My grandchildren that live out of state recently came for a visit. As usual we needed a project to work on while they were here. Thomas Edison once said "To invent, you need a good imagination and a pile of junk." I have the junk and my grandchildren have the imagination so coming up with something is usually pretty easy. This visit we planned to make an electric trike for them to ride. Check out the the two videos to see the trike in action.
We started with an old Amigo Scooter. We stripped it down, added some old riding lawnmower parts, a couple of wooden boards and finished it off with handlebars from a bicycle. Having a junk pile really came in handy since the only things we bought were 4 battery clips and a heavy duty switch from the local automotive supply store.
Our trike will operate on 12 or 24 volts. The higher the voltage the greater the speed. For simplicity we only have one speed - wide open. Our trike will do 15 mph maximum with freshly charged batteries, smooth flat asphalt and a small child. That is fast enough for most kids and too fast for others.Our average speed is around 12 mph. We are using two 12 volt lawn mower batteries in series for a total of 24 volts. We charge the batteries in parallel using a standard 12 volt automotive charger. You could charge the batteries one at a time if you are not comfortable changing the circuit from series to parallel for charging. We get about 75 minutes of continuous ride on flat asphalt and a little less on grass, gravel and hills.
We don't have brakes on our trike and don't plan to put any on it. Stopping is really not an issue where we ride. Coasting to a stop works fine and if the children want to stop quicker they just slide their feet.
Step 1: Where We Started
We started with this old Amigo Scooter chassis. We stripped off everything except the aluminum frame, motor and front wheel.
Step 2: The Wheels
The original 8 inch Amigo wheels had to go. We replaced them with 20 inch tires and rims from an old riding lawnmower. Fastening them to the Amigo motor axles was a bit of a trick. First we drilled 1/4 inch holes in the axle about 1/2 inch from the end of each axle. Drilling the wheel hubs was a bit more difficult because the place where we needed the hole was recessed inside the rim where we couldn't hold a drill straight to drill the holes. We got around that by grinding a slot on the wheel hub where we wanted to drill the holes. We then drilled 3/8 inch holes in the rims and used 1/4 inch bolts to fasten the rims to the axle. After a little grinding and filing we got the bolts in and were set to go. The larger the wheels you use the faster your top speed is going to be. Larger wheels also decrease the acceleration a bit, but these junior engineers keep this thing wide open all the time so acceleration is not an issue.
Step 3: Wiring It Up
We used some old stranded 14 gauge automotive wire to wire the trike up as follows.
- One wire from a black battery clip at the battery compartment to the black wire coming from the motor.
- One wire from a red battery clip at the battery compartment to either terminal on the switch.
- One wire from the other side of the switch to the red wire coming out of the motor.
- One 12 inch jumper wire with a red clip on one end and a black clip on the other end. This wire won't be necessary if you only use one battery.
If you are using one battery just hook the red clip to the positive battery terminal and the black clip to the negative terminal and you are ready to go.
If you are using 2 batteries hook the red clip coming from the switch to the positive terminal of one battery and the black clip on the jumper wire to the other terminal of the same battery. Hook the red clip on the other end of the jumper wire to the positive terminal of the other battery. Hook the black clip coming from the motor to the other terminal of that same battery and get ready to ride.
The above wiring should work in all cases but if for some reason your trike runs in reverse just switch the red and black clips coming from the trike to reverse the motor.
Step 4: Finishing Up.
We fastened the lawnmower seat down with self-drilling sheet metal screws. The bicycle handlebars fit the Amigo steering column with no modification so all we had to do was tighten one bolt. We built a wooden battery box and fastened it to the rear of the trike with screws. We also put two wooden boards on the front for the kids to rest their legs on. The trike looks cooler without the boards but is a lot more comfortable to ride with them. Putting the switch on a bracket and fastening it between the seat and steering column finished it off. Then it was time for the fun.
Step 5: Taking It Further
Interested in taking it further? Try these suggestions.
SPEED CONTROL - We didn't have the original motor speed control module from the scooter so we just used a switch. If you want to control the speed you can get a scooter speed module for less than $20 online. Add a potentiometer and you are set to go.
BRAKES - Out trike doesn't have brakes. If you want brakes you are on your own designing and installing them.
MORE SPEED - Add another battery for even more speed. - Teenagers and adults will naturally want more speed and another battery will take you in the area of 20 mph. The Amigo motor is rated for 24 volts but it will operate on 36 volts. Just keep in mind that it won't last as long as it would at 24 or even 12 volts but hey it is eventually going to give out at the lower voltages too so if you want the extra speed go for it.
GO SOLAR - It would be pretty easy to put a solar charging system on a trike like this. A little roof over the driver with solar panels on top would be the crowning touch. You can get a three panel solar system and charge controller from Harbor Freight for around $200 and never have to hook up a charger to the thing again.
This is one project where the improvements could go on and on forever. Your time and budget are the only limiting factors. No matter how elaborate or simple you make it, an electric trike is a lot of fun for everyone. Happy Making.