I wish I had a complete plan before I started this project, but as with any project like this things are improved along the way. Some things work, and some things don't. I knew that a wanted to create a different suspension system for the second version, but unfortunately my first attempt left me pretty unsatisfied. I now have a system that I really like, and though time consuming is relatively easy to build.

The arms start out as old fence post which were made from 50x50x3mm angle.

These were then split along the top to make the top 25mm for clearance in the frame. I split them by scoring a line with an angle grinder and then using a sawzall with a metal cutting blade. Holes were then drilled to allow for the wheels to be bolted as well as the pipe which holds the shaft that attaches the assembly to the frame.

Pieces cut for assembly

Welding with my trusty batteries and arc stabilizer.

Clamping everything together for welding.

I needed another piece that could sit on top of the arm and hold the motors. This piece needed to be able to slide in order to tension the chain. This was made using the same 50mmx50mm stock.

To allow the motor mount to slide I had to make slots in the suspension. I started by drilling a series of holes, and then cutting them out with a small grinding disk.

I added bolts and mounts to hold the motor and to secure the assembly to the arm. I also added mounts to attach the shock absorbers.

Then everything got a couple of coats of red oxide paint.

After the paint dried everything was reassembled.

Close up view.

Quick video of how the tensioning system works.