In recent years, I've been left without huge engineering hobby projects.  With BattleBots currently in limbo while Discovery Channel and Warner Brothers figure out what their programming plans are, our team has had some time to relax and indulge in some other hobbies.  Those hobbies range from buying a hydroelectric dam, to restoring old cars, and hosting small combat robot events.  However, we all seem to enjoy getting together to enjoy building and racing electric go-karts.  

I had never built a go-kart before, and decided the time was now.  My first forays into research were like drinking from a firehose.  There were so many decisions to make, from kingpin angle and wheel size to center of gravity and ackermann steering geometry.  Due to this deluge of information, I decided to start with a few more "known goods", I would take a kart that already existed, and convert it to accept the 15 HP electric motor that I had scrounged from a BattleBots competitor, Valkyrie.  After more research, I chose the Honda FL250 "Odyssey".  More specifically, I chose this one:

This example had a number of advantages:

• It was cheap
• It had functional steering and suspension (bonus for offroading!)
• It had a seat and a rudimentary roll cage, good for not dying.

The first order of business would be to make this big lump of 80s iron ready to accept an electric swap.  The CVT axle assembly, unfortunately, had to go: it weighed 58 pounds on its own.

Next, the chassis had to be fully stripped and fixed.  Every joint was tired and frozen, so everything was in dire need of a re-greasing.

The frame itself is actually quite cool.  It's designed with a lot of automotive design language, for better or for worse.  It means that it's quite durable, but also quite heavy.

The kart got a fully new rear axle, and 4 new tires.

Next up was to figure out how the batteries and motor would situate.  I decided to have them straddle the kart width-wise, that allowed for the easiest removal and also a good, safe carrying condition.

Now, it's time to boot up SOLIDWORKS.  Using my measurements and the assembly tools, I drafted up an underslung battery box, as well as a motor mount.  I chose to have the motor mount directly tied to the rear shaft.  This would allow the mount to maintain the center-to-center distance for the final chain run, and could move if I ever want to add rear suspension.  This is where the project sits now.  I'll be ordering steel and aluminum soon, and will hopefully be driving shortly after that.  I'll keep y'all updated!