This is a school project in which I'm making a dual motor electric trike to carry one person. I've used many different metal working tools such as a lathe, milling machine, MIG welder, and plenty of hand tools.

Step 1: Main Frame Construction

Picture of Main Frame Construction
Materials need for the main frame

- 35mm box section steel or similar (roughly 3 meters of the stuff)
- old BMX headtube


- steel rule
- tape measure
- scribe
- hacksaw or electric auto one!
- engineer's square
- 200 amp MIG welder
- hand file (rounded and flat)
- electric grinder (speeds up filing and cleans up welds)
- various clamps and vices

1. Cut the box section steel to lengths of 1000mm (1 metre) for each piece
2. Front piece of steel is shape around radius of BMX headtube at a 10 degree angle of rake
3. Cut off headtube from BMX and file or grinder
4. File small 45 degree chamfers and the ends of the box section steel around the edges for better welds
5. Weld all these parts together as pictured
6. Grind on top of frame at the "t" join for a nice finish

p.s you don't to follow the exact dimension, just my design has those

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smegger (author) 1 year ago

Indeed I have. I did think about this but basically I've just designed it so one motor will be slightly stalling when the other is running normally when cornering. The motors are not powerful enough to start 'tyre scrub' - as in spinning whilst cornering. So therefore in this kind of application I didn't feel a differential would be necessary.

If I did use one it would completely change the frame design too.



hello, i noticed you used two motors, would one motor go free wheeling when you are turning to increase maneuverability? two wheels rotating at the same speed when turning would burn up the rubber that is why they came up with the differential.

great project!!!

Please advise.


gluvit1 year ago
What do you say about 2 18v battery's? Will this supply the power? my power source is a drill battery (2 of them) And would like to know your opinion. my engineering goes only so far with high School classes.

Drill batteries are only 2400 - 5000 mAh

Those batteries will not be enough. You need something with at least 30Amps

smegger (author)  MineCraft-Nuffsaid2 years ago
First work out the power (watts) needed for your vehicle- this will depend on factors like the weight, top speed, acceleration required, hills you may need to climb. From this you can roughly work out what current your motors are going to draw from the batteries.

Batteries store energy and will discharge at a rate depending on the amount of current the motors are requiring. What Amp hour rating are your drill batteries? You will need to connect them in either series or parallel to combine them? Connecting them in parallel will double the amp hour and series will just double to voltage.

Read some electronics theory first to familiarize yourself. Go to your library and speak to your tutors/teachers. This will help you in your choice of motors and batteries. Drill batteries have been known to be used in radio controlled combat robots for competition. I just have a feeling there amp hour rating wot be sufficient for a decent run time when used in a one person vehicle.
Thanks, luckily my neighborhood has no hills (Lucky me), the i was going to use the drill entirely so there is less electronics to make me sunny side up. if you need an idea on my vehicle, look up the Drill kart on MAKE.com
gurustein4 years ago
Where can I get Motors for Cheap cost.Iam in shortage of money.
smegger (author)  gurustein2 years ago
Have a look at wheelchair motors and spare electric scooter motors (like mine). Check ebay and scrap yards for motors
From what I saw, he built the motor
freeza363 years ago
wheres the cup holder? lol nice job man
book543214 years ago
How much I have a trike
Vinsu4 years ago
goeon5 years ago
 Thats pretty freaking awesome ! keep up the good work man
every thing about it is to  complex
make it easier
smegger (author)  m5industriesinc5 years ago
 Hi there, what part of it are you talking about? Or is it just in general? I've stripped this trike down and should hopefully be starting afresh with either a simplified version of this or an entirely new concept with the view to make the construction easier.

psymansays5 years ago
 That looks like a lot of fun, especially in the video. It actually looks fast, too, for its size and wattage.
 How long do the batteries last?
smegger (author)  ibuildcoolstuff5 years ago
 Hey, thanks for your interest, if you scroll down you'll see a short description of how it ran and rough battery discharge times ---->

 What kind of wheels are you using? and were did you get them?

smegger (author)  shadowkiller5 years ago
 The wheels are fully pneumatic and are 10" in diameter. The have a pressed steel hub made of two halves in which 4 bolts hold them together. Hole for axle is 5/8" dia.

I actually got them from the same place as the batteries- a local hardware farm store. They had a selection and once I saw them they looked perfect!

You can also get them here: www.technobots.co.uk/cgi-bin/ss000002.pl

Hope that helps!

smegger (author)  smegger5 years ago
Oh, these are just the rear wheels

The front is from a kids bike- alloy rim etc etc

ElvenChild5 years ago
 whats the top speed of it
smegger (author)  ElvenChild5 years ago
 I would guess around 20mph on level tarmac. Thats just my comparison to what it feels like on a bicycle.
geeklord6 years ago
Not trying to rip on your design or anything, but couldn't a speed control easily be made with a MOSFET (or four MOSFET's for forward and reverse), a microcontroller, and a potentiometer attached to a trigger? I see all these speed controls and imagine that they're pretty simple on the inside...
smegger (author)  geeklord6 years ago
Yeah pretty much! Your right, I'm not amazing with electronics and I wouldn't really know how to build one. The one I have here is controlled with four MOSFETS, the 40 amp version only has 2. If I made one I would want to know how it worked properly, not just build it from some kit or something. Plus, due to my time constraints I couldn't build one. It was tight enough as it is- I had to build it through the last night to get it into school on time! Anyway, it would definitely be interesting to design your own, I might look into it and see what people have done, i just need the theory first! Sam
Once I get my AVR's up and running I might be able to build one. I could use a 555 timer too. Whatever, cool instructable!
matt6 years ago
where did you get the batteries from?
smegger (author)  matt6 years ago
Well I got them from a local farm/hardware store (in my village funnily enough called Browns) that happen to sell different types of batteries.

The batteries are (about £40 each) :

Numax 'Ev Power', Deep Cycling Battery, 32ah, TYPE 896cxt

You could probably find an alternative to this as there are plenty of other manufacturers.

Here is a great site to also look at for information on building electric vehicles:



very cool
altomic6 years ago
cool project. how fast does this thing go? how far? how long? thanks
smegger (author)  altomic6 years ago
I didnt exactly design it with a very specific speed and I guess it goes around 15-20 mph and obviously it depends on the terrain/ topography to how far or long it runs. When running it on tarmac up and down my street (fairly flat) it lasted about 20mins and this was running it full speed apart from turning. Thanks for you interest though, you thinking of building something like this? Also at the moment the trike is just sitting in my garage, I need to get it going again! Charge up the ol batteries! Cheers Sam
Dude i love this hopefully i will be making one of these as me & my dad have just bought a mig welder
smegger (author)  stephenniall6 years ago
brilliant! I wish I had a MIG welder at home at the time cause it would of made the project a lot quicker!
nireves17 years ago
maybe you could tell us witch motors you used?
smegger (author)  nireves17 years ago
The motors I used are originally for electric scooters and only used as a single motor. But I thought I might as well double the wattage by having two 24v 300W motors. They used 4 bolts to mount and they can be found here:

Ebay 350W 24V Scooter Motor
PKM7 years ago
Now why didn't I get to build stuff like that at school? **unfair** It looks like it turned out pretty well- have you found out the usual electric vehicle performance measures, ie top speed/range/hill-climbing ability?

Also, I second noah's question- is this a GCSE/A-level tech project? And kudos for actually going into detail about the shop work part, not just "throw the sprockets in your lathe and turn them down so they fit the wheels" :)

smegger (author)  PKM7 years ago
Hi there, the project was for A- level and the brief was simply to promote the engineering department at our school and electric powered vehicles. I haven't found any accurate measures yet but I think it can go about 18mph tops on a flat and it runs for about 25 mins on tarmac at varying speeds. Thanks for your positive comment PKM, will hopefully test it properly sometime and post up the results!
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