#1 Design and components - Pavlov project: Building a quadruped robot 

Hi! Actually the idea is to build my own servos from these DC motors using a potentiometers as a feedback (same idea as a servo motor). Stepper motors are very heavy, and if you need a lot of torque like in this case, steppers motors are very expensive..

i think he´s using blender

The yellow parts in the design :)