This is something I've been pondering, but with my experience with the Lynxmotion Scout in the past, using the 645MG, I didn't think that it was really possible to do a reverse knee/chicken walker type of bipedal with a reasonable DOF (about 12 or so no including the arms) with the 645MG.
But it's something I've noticed years ago when the Kondo first released their KHR series of bots. Their servos are on par with the 645MG's torque, so would it be possible to make a KHR-1-equivalent type of bot using the 645MG?
Has anyone tried this? I know that the 645MG servos are more than enough for the bipedal like the BRAT, but what about more sophisticated bipedals like on the same level as Bioloids, Kondo KHRs, and etc? I've seen 645MG bipedals, but they were quite wobbly. I guess the KHR-1, 1HV, 2HVs, were just as wobbly it seems, but Kondo seems to have done something right to make it so graceful.
Are the Kondo servos lighter? Is that the trick?