Walter is a Robot Head Built From Scratch.


[Chris] has put together a robot head that is impressive at first sight. [Chris’] robot, Walter II, becomes even more impressive when you realize that [Chris] built every single part from scratch. Many of Walter’s parts were created using machines [Chris] built himself. Walter is a robot neck and head. His upper neck joint is based upon three bevel gears.Two steppers drive the side gears. When the steppers are driven in the same direction, Walter’s head nods. When they are driven in opposite directions, the head turns. The end result allows Walter’s head to be panned and tilted into almost any position.

A second pair of motors raise and lower Walter’s neck via a chain drive. What isn’t immediately visible is the fact that a system of gears and belts maintains the tilt on Walter’s head as his lower neck joint is actuated. For example, if Walter’s head is facing directly forward with his neck raised, one would expect him to be facing the ground when the neck is lowered. The gear/belt system ensures that Walter will still be facing forward when the neck joint reaches its lower limit. All this happens without any movement of the neck motors. [Chris] definitely put a lot of thought into the mechanical design of this system.

The mechanics help keep the electrical system simple. Two Arduino Nanos run Reprap teacup firmware. This means that Walter’s native language is actually G-code. One Arduino controls the bevel gear joint (X and Y in the G-code). A third Arduino controls the neck raise/lower (Z in G-code). A tower of stepper drivers complete the system.  We think the head and neck would look great on top of a track drive system.  Number Five is Alive!

[Thanks Jon]


  1. hemalchevli says:

    Great build, I especially like the neck mechanism.

  2. ch0mik says:


    I think this project will be good solving as Antenna Rotor or GigaPanorams rotors

    with Regards

  3. Tomasito says:

    I really like the differential style gears on the head.

  4. smilr says:

    To echo one of the youtube commentors: This is freaking awesome, but does he also have a buildlog for his CNC?

  5. GAP says:

    I find more awesome the fact that he also built his tools. Impressive work

  6. reggie says:

    Strap a telescope to it and track stuff in space, I wonder what his periodic error is and whether it will rotate with precision at 1 revolution per day?

  7. I am agape in awe. The build that all other machining projects should be measured against!

  8. Phil says:

    Early version of Wall-E?

  9. Danny says:

    i am walter the wobot, i am faithful to my master

  10. Hey guys, thank you all for the kind words. I am Chris, I built this guy. I have been getting a lot of questions about the CNC itself, I am working on a proper video now with all the info anyone could need.

  11. Philip says:

    I’ve seen that neck assembly on older industrial robots, driven with belts just as shown. Fantastic that he made his own gears! Curious about his CNC build–very nice looking–and the software that drives it all.

  12. supershwa says:

    Johnny 5 is ALIVE!

  13. daniel says:

    Hey Chris, really impressive what you´ve built! Mesmerizing to watch how smooth the whole assembly moves. Thanks for taking the time to share, was almost more interesting (for me) to see the build progression.

    Looking forward to the CNC vid!

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