BAHX uses what is known as a “standard tripod gait” in order to move around. This means that the middle legs rotate on the verticle plane, and the front and back legs rotate on the horizontal.
The middle legs provide “lift” and the other legs provide the forward or backward motion.
This is a tried and true method of propulsion in hexapod robotics, and it enables the bot to turn either way when needed very easily when using three motors.
This gait is defined as “simple” because it uses only three motors to accomplish its task of walking. More complex hexapods are out there that mimic lifelike walking in a much better way, but require 12 or more motors in order to do so. If you look at the image below closely, you can see that the middle legs actually move forward and backwards, AS WELL AS up and down.
In other words, the legs are moving in two degrees of freedom. In order to accomplish this you would need two motors per leg, (or a complicated gear system)
The standard tripod gait can be accomplished with two motors, in which one motor controls the outside legs, and one for the middle leg assembly, but the turning ability is limited on such bots. There are even some examples of one motor hexapods out there and these are really quite a neat engineering feat:
I went with the three motor mechanical design because of its simplicity, but also because it seemed to have the ability to evolve in to a design that could navigate around obstacles effectively, and traverse over rough terrain. This design doesn’t stumble forward… it actually walks.