3-dof biped

Hello. I had a plan of making a biped with 3 dof on each leg, so it could walk with lifting legs and not by sliding.I tried 2 different designs and none of them worked, it would fall down every time he tried to move the balance to one of the legs. Then I read an article that said that you can do what i want with 4 dof-s, but without the knee joint, and then movement looks weird becouse it has to swing his leg around for climbing and stuff like that.

So my question is, is it possible to make a 3dof biped that actualy walks?

I have servos for one more dof, but I don't have the right tools to shape and cut plexiglass, and that is the only material that is available to me right now, so I don't want to waste alot of time trying designs that wont work, becouse it took me 2 days to make first two designs, so if you have ideas for 3 or 4 dof bipeds that can walk please share them =)

Thank you in advance.

Lynxmotion has one

Lynxmotion BRAT

It has a curious gait to say the least but it has proven its mobility in several designs.

Hope

This has given me some hope!
That was basicly my first design, but I did it badly, I will redo it then, and try to make it more similar to BRAT so it would work =)

Thank you.