The 3d printed battery operated robot is based on my type 3 claw foot walker mechanics. I re worked the design so that the robot would have moving arms head and meter dial on the chest. I added LED's for the yes on mine. I used a low cost dual shaft gear motor , a dual AAA battery holder and a slide switch. A live build video on you tube can be found here.
I just added a Motor Small Gear New file in case you have a problem with the small motor gear not fitting right to your gearbox motor, I have found they are not all the same , so the new motor gear has the D slot all the way threw the gear so it can slip all the way onto the motor shaft.
The gears I printed at 0.15 and the arm lever and the head lever have supports.