With the dramatically increased access to tools and resources that came with going off to college, I wanted to build a second electric vehicle, more refined, more powerful, and more fun than my previous one.  This is the result of my efforts.

This was my first big project at MITERS, the MIT Electronics Research Society, where, for the first time, I have access to real machine tools.  Over the course of this project, I learned how design parts and assemblies in Solidworks, and got fairly proficient at using a manual mill and lathe.  

The basic design for this vehicle came from the classic Radio Flyer tricycle, but this was scratch built with a number of performance increasing enhancements.  It features side-to-side leaning for better cornering,  an incredibly oversized brushless motor, an eight speed manual transmission, and a custom differential, among other things.  It has a  (untested, because I'm not brave enough) top speed somewhere in excess of 40 mph, enough torque to throw off the unprepared rider, and is guaranteed to get you funny looks every time you ride it.

Submitted by MITERS for the Instructables Sponsorship Program

For the Make-To-Learn Contest:

What did you make?

In case the title was not clear enough, I made an electric tricycle.  While it may be comically small, don't confuse this for your average pedal-powered Radio Flyer though.  This vehicle was designed solely to be a fun thing to ride, and is more comprable to a go kart than anything else.  Although it is an entirely impractical vehicle for doing anything useful, it has been suggested that I ride it to my classes.

How did you make it?

The idea for building this came from a combination of wanting to build a better electric vehicle than my previous one, and from getting the chance to ride someother very small but very fun electric vehicles.  The parts were first designed in SolidWorks, and then machine manually, using a combination of hand tools, a mill, and a lathe.  Since I designed most of the trike on a computer before building it, I did not have to change any of my designs half way through.

Where did you make it?

I made it at MITERS, MIT's student run shop/hackerspace.  In addition to having the tools I needed, MITERS also has lots of awesome people who know about making a huge variety of different things.  Especially electric vehicles, multicopters, and Tesla coils, though.

What did you learn?

I learned how to CAD in SolidWorks, and how to use a manual mill and lathe.  I also got more familiar with brushless DC motors, and how they are controlled.  Most of the actual building of this project went smoothly, so the biggest challenge was diagnosing some very unusual motor and motor controller problems I had.  It turned out that the motor I used had an intermittent internal short.  Sometimes it would work just fine, which made it very difficult to diagnose exactly what the problem was.


Step 1: Why Did I Build This?

There are a lot of answers to that question.  If you plan on building some sort of silly electric vehicle, or anything else for that matter, any or all of them may apply.
  • Because Building Things!  Building things for the sake of building things is a perfectly valid reason to start a project.  I have built plenty of things that I have rarely used afterwards.  The process of designing and building things is often at least as rewarding as actually using the things you build.  Take my Nyan Hat project, for example.  2 weeks of building, and I've used it in total for an hour tops.
  • Learning new skills.  Before this project, I had hardly used any CAD software beyond Google Sketchup.  Now I am fairly comfortable modeling parts and assemblies in SolidWorks, and Autodesk Inventor to a lesser extent.  I also got a lot better at machining things.  The frequency at which I made terrible noises on the mill and lathe decreased significantly over the course of this project. 
  • End product.  Before building this, I had some experience riding some other small go-kart like electric vehicles, Chibikart and Tinykart.  These vehicles were incredibly fun to ride, and I wanted to build something with similarly good handling and performance.  At the world Maker Faire in New York, I took my scooter on the Power Racing Series track, and unsurprisingly found that it doesn't corner very well.
  • Because I thought the idea was pretty funny.  I really liked the idea of a vehicle in the form of a toddler's tricycle with an excessively large motor and dangerously fast top speed.  Nyan Hat again is another great example of something built mostly because I thought it would be funny.
  • Because I acquired a very large electric motor. I didn't design the tricycle because I got the motor, but I did build it when I did because I got the motor.  I have started plenty of projects simply because I wanted to put to use some really cool part I found.
<p>What engine do you use? where to buy? Thank you</p>
<p>This is the reason I want to go to MIT so badly, and I'm trying to learn as much as possible, but looking further back, the stuff you did when you were my age, is incredible and makes me doubtful of my real chances. </p>
<p>This is the reason I want to go to MIT so badly, and I'm trying to learn as much as possible, but looking further back, the stuff you did when you were my age, is incredible and makes me doubtful of my real chances. </p>
Can I purchase this? It looks so much fun :)
Can this be done with a small gas engine?
Im sure it could be done. I think it wouldn't be ideal for riding to class because it would be loud, but most people who make this would probably build it for street pleasure so yes!
Heed Ben's warning about the danger of this step! Batteries contain a surprising amount of energy, and shorting them can be very exciting (but not in a good way!) I would stongly recommend that you use tabbed cells as well. One thing that will severely shorten the life of any cell is heat. Tabbed cells have a solder tab spot welded onto the ends, allowing you to solder them together without getting the ends of the cells hot. Soldering directly to the button on the end of a cell risks overheating - melting the internal support structure - and causing the cell to leak or, if you're really unlucky, short internally - which turns the cell into a heat bomb!
Fabulous work!!!
Sweet &nbsp;ibble! &nbsp;I have been toying with the idea of putting something like this together. &nbsp;I have a couple 12 volt motors from cordless lawnmowers&nbsp;gathering&nbsp;dust and this seems like the perfect application. &nbsp;If it comes together I will do an ibble up myself and certainly&nbsp;reference&nbsp;your&nbsp;inspiration. &nbsp; Cheers.
<br>Nice engineering - You could do without the diff and just drive one wheel with little loss of traction and a saving in weight and complexity.
Certainly (although the weight savings would be pretty minimal - the differential weights only a couple pounds). The fist thing I say in the &quot;building the differential&quot; step is that there are a bunch of easier alternatives, single wheel drive included.
So cool! Nice work!

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