k-bot teardown

[Chris Albertson]

If you are a robot hardware geek, and I assume everyone here is, this first video is great.

“K-bot” is an new  open source humanoid robot.   It seems to be at a point of development now where it can stand on an uneven surface like grass and you can push it, and it takes steps to recover balance.  It can be teleoperated. The full hardware and software design is on GitHub.  You can buy one for about $10K or build it from the design files.

One design idea I like is the hands mount, exactly like a lens on a camera body.  They use parts from a micro 43 camera to make the mechanical and electrical connection.   The other design feature I like is what they call “clam-shell” but I’ve called it “exoskeleton” or “stressed skin”.  The part you see is not a cover but the actual structure.

But what I wanted to post is a hardware teardown.  Two designers do a complete teardown and take every screw and part off and tell you why they built it like they did.    They have design ideas that would work on other kinds of robots.   The design is astonishingly simple but strong and repairable.   

[Stephen Williams]

Nice!  I saw a reference, on a different project I think, using the micro 4/3rds lens mount.  Not a bad idea.  However, I could not find any reasonable source for both sides of the mating hardware.  If there is a good source, that is great.  If it includes the newer signaling connection block + pogo pins, way better.

Given laser cut metal parts, should be able to design 3D printed parts to create a similar solution.  And then it could be printed at different sizes, different strengths, with custom / robot-focused power + signal connections.  Need a plate that fits through another plate, locking upon twisting, with a center cylinder that aligns both.

The hand dock should not be at the wrist joint but further up the forearm, close to the elbow.  The forearm + wrist + hand should be a single unit.

The only major design deficiency I see is that I'm sold on having dual calf motors controlling the ankle joint for 2 degrees of freedom with differential control: Both motors go up, toe goes down.  Both motors go down, toe goes up.  If one motor is offset from the other, the foot swivels to cant left/right, at whatever angle both motors are set to.  I have pictures of several robots that use variations on this.

Two degrees of head control can be done with the same joint principle.  Then add rotation separately.

sdw

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Stephen D. Williams Founder: VolksDroid, Blue Scholar Foundation 650-450-8649 | fax:703-995-0407 | s...@lg.net | https://VolksDroid.org | https://BlueScholar.org | https://sdw.st/in