Eli-Kart and Motor

After a busy spring semester, I'm finally done! As I mentioned in my last post, I was an assistant for the electric vehicle section of 2.007. To go along with this, I worked on Eli-Kart for my undergraduate thesis. Now that the semester is over, I can tell you all about it. But first, a video!

Eli-Kart's design has remained largely the same. See how similar they look? However, I also designed and built a large custom brushless motor that could be used to replace the hobby aircraft motor seem in the original design. I used FEA and CAD to help with the design. Here's an exploded rendering of the motor, along with the results of my finite element analysis on the motor using FEMM.

With the hobby motor, Eli-Kart tops out at about 20mph and has good acceleration (depending on the load). The motor overheats if you beast it too much though, but its good for cruising. If you're interested in learning more about the process, I created an Instructable that details the design of both the go-kart and motor.

Eli-Kart Design

I like starting posts with shiny renderings.

This is Eli-Kart!  It's a miniature, three wheeled, 2-seater go kart.  Its frame is simple yet robust, and is made up of a 1/2" sheet of clear plexi supported by steel box extrusions, allowing you to see through most of the vehicle.  It has 8" pneumatic tires, Ackermann geometry steering, and a high quality brushless motor controller.  The battery pack is pretty high powered at 39.6V and 7.5Ah which should give me around 15 minutes of fun.  Right now I'm planning on using the same motor I have on 2x4 Scooter, but I'm going to be retrofitting my own custom motor eventually.

Getting more into the details, the steering wheel will be waterjet with the words "Eli Kart" on it, then welded together.  There will be brakes on the back wheel, but the throttle is yet to be determined.  However, both throttle and brakes will be hand operated.  Other parts of the steering mechanism are waterjet and assembled with t-nuts, as you might be able to tell from the picture above.  The controller is a Kelly KBS KBS48121 with the high speed option (allowing up to 70,000 ERPM), and I will probably install external hall effect sensors on my motor so I can control it.

This has easily been the biggest design project I've done.  Luckily, doing all of the designing in Solidworks will make it very simple to build.  Apart from the welding and machining a few parts myself, all I need to do is waterjet some aluminum plate, and order some McMaster parts.  I will be using Eli-Kart in my undergraduate thesis so I'll provide updates when I finish!