Introduction: Morgan Electric Trike
Second Prize in the
Wheels Contest 2017
Everyone is crazy about the electric commuting nowadays, we wanted to join the thrill too!
Morgan is a great fun vehicle for dad and kids. It can be driven safely by a 5 y.o. as well as a 12 y.o. kid and it can give dad a drive too. Its construction takes less than 50 hours with all parts and tools at hand. The speed is just awesome! We have used a 250W hub motor kit for e-bikes and 36V of batteries.
With this and 45kg of weight (including a young pilot) it can reach up to 25 km/h with a range of 50km (6Ah battery capacity).
Kits are available from various e-bike suppliers. Nowadays you can buy even 1000W motors and 48V batteries (the more voltage the higher speed, the more watts the higher torque). However, there are legal limits to their use on bikes. Also, safety needs to be addressed in higher speeds and higher torque. So, have fun and drive safely!
See our comments on welding at the end of the instructable.
We are joining the Wheels contest, so if you like our vehicle why not giving it a vote? Thanx!
Step 1: Materials
- square tubing metal bars - 15x15 mm, total approx. 6m, Iron flat bars - 30 x 3mm, total approx. 2m, iron round bars 10mm cca 1m
- electric bike kit (hub motor, disc brake, breaking line, regulator, charger) + 2 wheels, we have used 20inch diameter
- batteries - lead type, traction bateries 3x12V, 6Ah
- plywood for seating and flooring - 8mm thick, scrap pieces really
- plywood for bonnet, 2m2, 3mm thick
- foam for seating, 100x50cm, 5-10cm thick
- fabric for upholstery (heavier fabric is better)
- Arduino nano, some leds, resistors, buzzer, button and switch
- various nuts and bolts for the bonnet and seating mounting to the frame
- brake light
- leather strip for steering wheel
- spring for suspension and shock-absorbtion (not necessary)
This project is constructed mainly from square tubing 15x15mm, but other material would do as well. You can reuse parts from old bikes and other scrap. You can easily adjust the design according to your material availability. Visit your local scrapyard before you start.
Step 2: Tools
- Welding machine and electrodes, magnetic holders, safety equipment
- Grinder and metal hand saw
- Jig saw (for plywood parts)
- Stapler gun
- Other general tools (pliers, files, drills)
- Soldering iron
Step 3: Frame
From the very start it was clear that ergonomics is the key to the project success. So we laid a large paper on the floor and put the pilots in and virtually designed the car around them. Then we pinned the drawing on the garage door to refer to it during the whole construction. We also developed a simple project board to sequence the work, plan purchases and understand the risks.
The plan size was 1:1. The frame dimension without the rear wheel fork can be seen on the drawing. The fork lenght is a bit more than 10 inches as the wheels are 20' in diameter. The frame has got a raised level - the second level of tubing is meant for sturdines and to hold front wheel steering brackets. It naturally resulted in a raised seating. The dimensions are the same exept the backside, where the frame forms a triangel.
Make your drawing first and than cut the tubing according to the drawing. Some parts need to be cut in angle so that you do not need to grind too much material off before welding. Material is easy to cut manually with a metal cutting hand saw or you can use a grinder with cutting disks. Wear goggles, gloves and use solely equipment in a good shape. Avoid cracked disks.
Brackets are made from 3 flat pieces welded together and drilled to hold the vertical bolt. Weld the brackets to the main frame from the fork side. Other flat pieces are welded to the back fork to hold the disc brake mechanism and also the wheels (from below the frame). The angle is not critical, just measure how high you want to ride.
Suspension pieces are made from the same flat pieces just a bit smaller than the brackets. Later we made another pair of shorter brackets to accomodate a spring as a simple shock absorber, but that is not necessary.
Step 4: Wheels!
After the frame grinding and painting, we added floors and wheels.
Floors are drilled through the painted plywood and bolted with washers and nuts to the frame. Seating and a back rest cut in arc is also drilled through and bolted to the frame.
Front wheels are connected to suspension parts and the suspension is fitted to the frame with one 10mm bolt going through the bracket. The front part of the suspention is connnected with flat pull steering to the steering rod. The back wheel is mounted to the flat pieces previously welded to the frame from below.
Take the measurements from the work as you go to be as precise as possible when drilling the mounting holes for the rear brake.
Step 5: Steering
The steering wheel is made from a simple rod manually bent on the wise and welded at the end. The center cross is made from smaller flat pieces. On the back of the steering wheel there is a hex nut welded to the cross. The steering rod is grinded with a file to fit in the hex bolt. The rod is also drilled at the steering wheel end and fitted with small treaded pipe to screw the steering wheel to it. We wanted to have the steering wheel removable, but you can also weld it directly to the rod to save some effort. For a nice touch, we wraped it with a leather stripe glued to the ring and than greased it with hand cream for the right colour and softness. You can get the long stripe from a rounded piece of leather by cutting the stripe in spiral.
The steering rod goes through two simple flat pieces with holes, one on the front wheel frame and the other one on the round part of the frame holding the bonnet. It is secured in place with one washer with a bolt.
Holes in the flat piece at the end of the steering wheel rod determine the rotation radius of the car. Mark the right holes for drilling into the flat steering pull rods with perfectly alligned wheels to avoid missalignment that would cause the car to go wobbly and also wear off the tires (our case before adjustment). If you have the chance you can also include a set of nuts and treaded rods instead of flat ones to fine tune the front wheels accuracy. But that brings extra costs and effort we don´t find necessary.
Glue the thread of the 3 bolts (two at the suspension and one at the flat piece at the end of the steering rod) with Locktite glue or a nail polish drop to keep it from unmounting during the ride.
Step 6: Upholstery
We took a 10cm flat piece of polyuretane foam we found in a shop. We cut it to shape following the seat and backrest and stapled it to the plywood through the fabric and foam in a zig-zag fashion that helped to create an old-time fancy look. We recommend to use heavier fabric (denim and alike) as the red we used started to rip off the stapples during the use.
We had an ambition to have an adjustable seat from a racing kart for different pilot sizes, but that again comes with extra cost. Our preferred solution, however, enabled taking 2 kids on board at the same time.
Step 7: Pedals
Pedals are made from scrap plywood. They are bolted to door hinges and supported from the back by springs taken from old clamps fixed with stripes. On the brake pedal we have mounted bowden line leading to the rear brake and the gas pedal is simply transfering the motion to the finger accelerator delivered together with the electric motor kit. We thought this would not last long and expected the need to change the design, but on the contrary, it has needed no extra touches since the installation. Looks odd, but works fine :-).
The brake pedal has two metal pieces touching each other when the pedal is in action. This forms a simple switch between the brake and the battery. Cables are glued with a hot melt to the floor and strapped to the frame.
Step 8: Bonnet
Every car needs one, right? The bonnet is made from 3mm thick (1/8) plywood 1250x1200 mm bent naturally over the round part of the frame and bolted to the bottom part of the frame. The bonnet is made from two pieces, front and rear. We recommend to use a thicker paper first, find all cut-outs for the frame and transfer the shape to the plywood.
Cut it with a jig saw, test fit, paint it and finaly bolt it to the frame. We have made some adjustments to the bonnet later so that on the picture you can see different designs. The bonnet is attached to the floor frame members and curved over the arcs welded to the main frame. In the back the bonnet is also screwed to the seat ply wood with the help of small wooden blocks.
The bonnet is painted ivory with stripes using a masking tape. The front grill is painted black with a handle to help with transportation and give it a bull-like look.
The cockpit part of the bonnet is fitted with a rubber pipe cut along the whole lenght and squeezed on the edge of the bonnet to provide the final touch to the cockpit and also some basic protection for the pilots.
We are considering fitting the car with safety belts too. Now we are looking for the proper parts.
Step 9: Power Up!
Based on the recommendation received with the e-bike kit, we used traction batteries 3x12V 6Ah connected in series to our full satisfaction. The hub motor could go with 48V and that would give it more torque and speed, but for the sake of dad´s sanity we are fine with this. You need a special charger with 36V voltage or you can unplug the 12 V bateries and charge them one-by-one with standard car chargers. But that is a pain in the neck and it takes a lot of time and attention to change all the wires, so we bought a 36V charger.
Bateries are quite heavy and on bumpy roads tended to jump around in the car. That´s why we made a simple bracket that is good enough to hold them in place. They are located below the pilot seat.
A regulator is hooked to the floor with simple plastic strips and the accelerator is fitted under the gas pedal. Connection between all the pieces - hub motor, accelerator, regulator, batteries and even horn and ligths is straightforward and connectors are color coded, so that they cannot be mixed up. Just follow the kit instructions. Secure the cabelling in place with plastic strapes to avoid damage to the wires during rides.
We bought a switch to change the mode between charging and driving, see the schematics and pictures. We also bought a female socket that fits the charger and mounted it into the bonnet for an easy charging service. By that, you can have a real plug-in vehicle and do not need to worry about unpluging the regulator first before you charge it up.
Step 10: Bells and Whistles
We had a long discussions whether this should be a sports car or a police car. To satisfy both pilots preferences, the bonnet has sport stripes. The policeman has simple arduino police lights and a sirene that goes on when you hold a button. The light is removable. The code is very simple, it is just two pairs of LEDs (white and blue), one button, a buzzer and a main switch. You can get all the setup from the INO file, as commented on. If you need more help in this direction, ask in the discussion. The main switch just connects a 9V battery to the arduino and it takes about 2 secs to start up. A police pilot can then press the button to switch on the horn (piezzo buzzer) and blink its warning along his chase.
We did not have the right casing for the light so we have dipped the LEDs in a clear epoxy in a small plastic container. When the epoxy sat, we have cut off the container and put the light on the top of the bonnet with a doublesided foam tape. Clear acrylic filler would do the same job. As the car is very silent it makes sense to use the horn when you pass the pedestrians, chase robbers or if you just want to show off. Actually the latter is the most common reason :-).
The car comes with the back mirror and brake light connected to the brake pedal with a simple switch. The light is connected to the 36V battery pack, the electronics being a part of the light that came with the e-bike kit. You will need a step down circuit if you want to use other voltage lights.
Our car also needed some lights for the wheels to provide some after-dark crew rides - we put some easy LED lights on the wheels air-valves.
We attracted a lot of attention with it and gave many rides to the kids living around. Hope you liked it and if you did, do not forget to vote for our project!
Step 11: Welding Notes
First of all, get acquainted with the welding machine, user's manual and also the type of welding methods you are going to use (MIG, MAG…). The mastery cannot be captured by these instructions, but there is a lot on the Internet and Youtube. However, the best is to practice under supervision of someone more experienced. Have a fire extinguisher at hand and use protection against sparks and hot pieces of metals. Cool down the works before you touch them. Use magnetic angle holders to help you keep the pieces together before the weld cools down.
Get all parts ready and clean them from oil, grease or paint. For small profiles you do not need to chamfer the joints to weld them successfully. Flat surface (table, flat ground) is a great help. Using magnetic angles to hold the pieces together is very handy. Spot-weld joints first and adjust it as needed before finishing the joint. Continue with the other parts checking the symmetry by measuring corners against each other. Check the quality and if the welds are foamy or with holes, file it first and repair it. Good welding joints are a pre-requisite of a sturdy and safe frame. Adjust the welding machine current to produce quality welds.
Welding the frame is easy and if you do not have any experience, you will learn the basics with this project. Just experiment with current and electrodes on scrap pieces before you start working on the frame. If you are not an adult, do not work alone, ask for help.
We have a be nice policy.
Please be positive and constructive.
What is the wall thickness of the 15x15mm tube?