After 10 years of driving the " Mini Jeep", I figured it was time to upgrade Kyle's go-kart.
We both decided that we wanted something that was fun, but didn't have so much power that it would get you into trouble.
It also had to be very reliable, and had to go over rough terrain. Once we had a basic idea of a design, we spent a few months gathering parts before we started the build. It's amazing how things come together if you're not in a hurry. After a few weeks of scrounging, we already had most of the major components to get us started. The best part, was that almost everything so far were freebies !!
 Before starting, I built a wooden platform with wheels on it to fabricate the frame. A grid pattern was drawn in 2" increments so that precise positioning of the parts could be done. Another reason was so that I could move the project off to one side in case I needed the use of my hoist.

The first parts I made were the front hubs. I was going to use existing ATV hubs, but they were too expensive, even used.
I found that most parts I ended up fabricating because of this reason.  

 Below is the process of heat treating the high angle spacers I made for the front rod ends. The material used was 4140.

 The picture on the left shows some of the parts gathered before starting the build. Amazingly, most were free or really cheap.
The rims were given to me by friends, and most everything else was from swap meets. I had to buy the seat new because all the ones I found were trashed.
The other two pictures are from brackets that were made on my CNC machine. Probably a bit overkill, but it gave me more experience on how to use this machine.