Hi everyone!

I'm 16 years old and I'm building my own full-size humanoid robot from scratch. This is the current prototype of the forearm, elbow, and hand.

For the hand, I reverse-engineered the finger mechanism used in the InMoov robot and recreated it using screws instead of the original design. The fingers are driven by servos that pull fishing line, which acts as artificial tendons.

The forearm rotation mechanism uses a 6916-2RS bearing, and I designed all of the mechanical parts myself in Fusion.

This version is only a prototype. It is printed in PLA and assembled with zinc-plated screws to keep costs low while testing the design. The final version will be printed in PETG and will use stainless steel screws, brass heat-set inserts, and nylon lock nuts (Nyloc nuts) for improved strength and durability.

Unfortunately, I can't demonstrate all of the movements yet because one channel on my servo tester is broken, so I can only test two servos at a time instead of three.

I'd really appreciate any feedback or suggestions. I'm improving the design step by step before building the complete humanoid robot.

My custom humanoid robot arm prototype (designed from scratch in Fusion)