This is going to get you into trouble: you're talking to someone who was actually involved in systems very similar to your ideas, and is giving you boots-on-ground examples of why the things you haven't considered are preventing your ideas from becoming reality. Your response is to argue with his reality.

I am a mech so I'm going to give you some homework.

Take a look at your hand. In particular, take a look at your index finger. Point it, then make a fist. Take note of where the extensor tendon anchors to your wrist. Point your finger and measure from your wrist to your second knuckle. Now make a fist and measure the same distance.

What percentage difference are we talking about? I measure about 4 1/2" and about 5". That's a difference of about ten percent... and that difference governs 90 degrees of flexion of the knuckle joint. 1% stretch, then equals a loss of ten degrees of precision in positioning your finger - that's parkinson's territory. And that's just a finger. Imagine trying to run if you could only plant a leg within about 10% precision.

Beyond that, motors don't lend themselves well to linear torque. As demonstrated, your total flexion for a rotational motion of 90 degrees is about ten percent... and the distance extended is handled much better by a linear ram (ANY linear ram). Motors are designed to spin, not rotate through a limited arc. And if you're actually moving your cables enough that they're being spooled, they've just become braided or twisted and are undergoing substantial deformation, which means their failure rate just skyrocketed.

briandmyers didn't have to tell you this. He's seen it and knows there are problems. He's worked on this, and he's a clever dude. You, on the other hand, chose to dive into sarcasm in a comment thread where you disavow MATH for fuck's sake. You can choose not to believe in math but I'm here to tell you, friend, math believes in you... and when you whip out "the lever principle" in a discussion of mechanical engineering in which you don't know the players, your interests are best served by not being a smartass lest someone comes along to demonstrate your dearth of knowledge.