Zero backlash, high “gear” reduction, high torque transparency, silent operation, and low cost. What is this miracle speed reduction technology, you ask? Well, it’s shoelaces and a bunch of 3D printed plastic, at least in [Aaed Musa]’s latest installment in his series on developing his own robot dog.

OK, the shoelaces were only used in the first proof of concept. [Aaed] shortly upgrades to steel cable, and finds out that steel fatigues and snaps after a few hours. He settles on Dyneema DM-20, a flexible yet non-stretching synthetic rope.

Before it’s all over, he got a five-bar linkage plotting with a pencil on the table and a quadriped leg jumping up and down on the table — to failure. All in all, it points to a great future, and we can’t wait to see the dog-bot that’s going to come out of this.

There’s nothing secret about using capstan drives, but we often wonder why we don’t see cable-powered robotics used more in the hacker world. [Aaed] makes the case that it pairs better with 3D printing than gears, where the surface irregularities really bind. If you want to get a jumpstart, the test fixture that he’s using is available on GitHub.

If you want to learn more about capstan drives, you absolutely need to check out our own [Sonya Vasquez]’s Cable Mechanism Maths. She brought some demos of her gear reduction mechanisms to Supercon, and they just feel like butter. (If I were a robot, that’s how I’d want my knees to feel.)

Did you know there is a Guinness World Record for the smallest humanoid robot? We didn’t either, but apparently this is a challenge attracting multiple competitors. [Lidor Shimoni] had a red hot go at claiming the record, but came up ever so slightly short. Or tall.

The former record holder was measured at 141 mm, so [Lidor] had to beat that. He set about building a humanoid robot 95 mm tall, relying on off-the-shelf parts and 3D-printed components of his own design. An ESP32 served as the brains of the operation, while the robot, named Tiny Titan, got big flat feet to make walking relatively stable and controlled. Small servos were stacked up to actuate the legs and create a suitably humanoid robot to claim the title.

Sadly, [Lidor] was pipped to the post. Some procrastinating in finishing the robot and documentation saw another rival with a 60mm robot take the record. It’s not 100% clear what Guinness requires for someone to take this record, but it seems to involve a robot with arms, legs, and some ability to walk.

Sometimes robots are more fun when they’re very small. If you’re developing your own record-breaking automatons, drop us a line won’t you?