Just launched on the Wevolver platform from Jochen Alt:
Jochen Alt has designed a high torque retro-futuristic industrial robotic arm, which he calls Walter. Instead of using servo motors like most DIY robotic arms, Jochen’s project uses NEMA stepper motors with a belt drive and a separate angle sensor to compensate for the relatively low precision of 3D printed parts.
The result is a 3D printable robotic arm with far greater torque and accuracy than would otherwise be possible. What’s more, Jochen spent four months refining Walter’s software, making the full stack including trajectory planning to achieve a smooth speed profile; Walter in action looks amazing.
Jochem cites the Thor project by from Ángel Larrañaga Muro as a source of inspiration. You can find out more about the Walter robot arm here.
Most DIY robots use servos for convenience since the encoder is already built-in and they are easy to control. The problem is that when it comes to higher torque the connection of the servo with the actuator becomes difficult to maintain with 3D printed material. If the servo or the flange moves just a little bit within the housing, the according play magnifies to a significant amount at the end of the actuator. Unfortunately, the required precision to avoid this is way above hobby grade components.