Here's my big robot claw hand, which I designed in CAD software then hand made out of MDF, some clear polycarbonate sheeting and various hardware. This project was more about form than about function. That being said, it does function perfectly and smoothly, but gear teeth cut out of MDF are just not meant for heavy duty industrial applications so the claw is mainly a novelty.
This one is about 2 feet tall standing on my desk. It's a good size and a neat machine and decoration but I'm definitely feeling myself compelled to make myself another claw scaled up by about a factor of 4 or 5. I'll be sure to post photos if and when I start the enormous robot claw project.