In view of the lower cost and documentation, I decided to use the G15 smart servo for my project. G15 is actually part of Cytron's Rero robotic platform, which apart from the controller and smart servo, also contains items such as various types of bracket, clips, adapters, wheels etc. At this stage I have managed to built the legs of the robot, these are 10 degrees of freedom with 5 motors for each leg. I also built my own custom controller using dsPIC33E micro-controller, this is hooked to a HC-05 Bluetooth module so that I can control each motor from my computer via wireless link. Below is a video of the first prototype machine walking. The robot is powered by a 11.1V 2200mAH LiPo battery pack.
I am using the standard U-joints and Inter-Connects from the Rero platform as can be seen in the video. Since the joints and interconnects use snap-in mechanism to hold to each other, the main issue with this is the assembly is not as robust as using bolt and nuts method of joining. There is noticeable movement or free-play in the joints among the brackets. This makes it difficult to come up with the correct angle for each joint during movement. To 'strengthen' the assembly, I make some U-shape plastic clips from 3D printers. As in the figure below, the long and short U-joints are hold in place by the clips in addition to the snap-in Interconnect. Epoxy glue is also applied to the plastic clip.
I am sharing the stl files for the plastic clip here: http://www.thingiverse.com/thing:928259