Here is my first pass at another robot using shifting center of mass but standard servos (7.2 volt) and brackets. It is a little more sturdy than my homegrown chassis.Moves a lot like my duckbot but with more motion options. I want to use it to study robot gaits a bit. I do have it sort of trotting by just moving the feet up and down a little and swinging the weight from side to side. Currently I am interpolating only two servos at a time but have the routine written to do all seven servos at once - not tested yet.