A few years ago, I made my first Lego Technic hand with pneumatics. Then, a little while after that, I made another pneumatic hand and an electric hand using linear actuators.
The pneumatic hands were always really slow and weak because all the pistons are old, the seal on the inside is dried out, and it was slow to build up air pressure. The electric one would have worked, but I don’t have enough switches or the longer actuators. Now, I’m trying to make one with strings that you pull for each finger, but I can’t really get it to work because the rings that the string is connected to don’t stay on the tip of your finger, so you can’t pull them all the way down. I also can’t really get the thumb to work because it needs to move on two axi instead of one axis like the other four fingers.
Stuff That Jack Built 