I have completed my first leg designs! This is actually my second design, but the first one I finished. I stopped work on the first design when it was apparent I was not getting the amount of leg extension and maximum height I am looking for. This leg design does not retract as well as the first design, but I think it is the best compromise so far.
Leg retracted:
http://www.thedynaplex.org/robotics/walkroll/img/leg2-retracted.jpg
Standard standing position:
http://www.thedynaplex.org/robotics/walkroll/img/leg2-standing.jpg
Leg with medium extension:
http://www.thedynaplex.org/robotics/walkroll/img/leg2-mid-extension.jpg
Leg fully extended for maxium height:
http://www.thedynaplex.org/robotics/walkroll/img/leg2-fully-extended.jpg
I have one modification to this design I am working on which my give me the best of both worlds - good extension and height with good retraction.
8-Dale