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    This robot was built as a locomotion type experiment, attempting to cross the efficiency of wheels with the advantages of legs. I worked on it on and off for many years, with a half dozen different versions. I'm currently thinking of a much better v6, and one day I'll actually make it . . .

    A quick evolution documentary of all the Carpet Monkey robots is shown in the first video.

    Version 1
    Version 1 was done as a project for a class with one other person. It was just a conceptual thing, but showed lots of promise. Its just basic remote control, with a receiver, battery, and two servos. The chassis was made from Lexan.

    Carpet Monkey v1 Angle View

    Springs were used to allow the arms to flex inward. This gave the arm reach to climb, but shortened when needed to reduce the moment arm and smoothen movement.

    Carpet Monkey v1 Claw

    Version 2
    Realizing version 1 had promise, a new version was made fixing all the various problems. The biggest problem was that the Lexan claws didn't have much grip, and wore away quickly. Aluminum claws were made by first designing the shape on paper . . .

    draw claw on paper

    cutting the design out . . .

    cut out design

    tracing it onto aluminum using a marker . . .

    trace onto aluminum

    then cutting it out with a bandsaw and a drill press for holes.

    bandsaw and drill out Carpet Monkey claws

    Carpet Monkey v2 angle view

    But the single claw design was inefficient. If I added a dual claw, shown below, it would double the speed and smoothen out the robot motion.

    Carpet Monkey dual claw

    Carpet Monkey dual claw

    Carpet Monkey dual claw angle view

    I still wasn't happy with the gripping power of the claw, so I tried out some Plasti Dip on the claws. It was fairly weak and wore away fast. I tried adding some fine sand (that I 'borrowed' from a Mars rover test bed, hehe) to the Plasti Dip mixture to improve dip rigidity, but it still wasn't good enough . . .

    Plasti Dip on Carpet Monkey claw

    I wanted Carpet Monkey to climb stairs, but its body would slip a lot on each step. As an attempted solution, I created a one-way friction grip thingy out of a sheet of rubbery plastic I bandsawed into this below:

    Carpet Monkey tail

    and attached this 'tail' to the bottom of the robot using Velcro:

    Carpet Monkey tail angle view

    It just barely managed to climb 4" stairs. Without the tail it didn't stand a chance.

    Carpet Monkey climbing stairs

    Version 3
    Version 3 was the first Carpet Monkey failure, but was meant to be a scaled up version. Note: I accidentally labeled another robot in the video as v3 but it was actually version 2. Version 3 just didn't work because I didn't properly calculate torque before building the robot. Hey, I was a noob back then! Anyway, enjoy the pics . . .

    Carpet Monkey CAD Carpet Monkey animation

    Here is the chassis next to version 2 for size comparison.

    Carpet Monkey v3 size comparison

    Some spacers added . . .

    Carpet Monkey v3 Structure

    One of the dual claws, with the largest servo I could find at the time (but wasn't strong enough).

    Carpet Monkey v3 dual claw design

    Fully assembled with springs added.

    Carpet Monkey v3 angle view

    Carpet Monkey v3 side view

    Carpet Monkey v3 top view

    Carpet Monkey effectively drags it's butt, so I added a big caster wheel there to improve efficiency.

    caster wheel

    Version 4
    After realizing servos were too weak in v3, I decided to go to DC motors. I attached them to a big steal plate, used some motor drivers, attached my claws, and wallah - it didn't work again! I'm so amazing!

    Carpet Monkey v4 angle view

    In v3, the claws were a bit flimsy, so I double layered them. I also used a compression pneumatic spring this time, but it was too stiff . . . should have used a much lower spring constant . . .

    Carpet Monkey v4 side view

    A rear view, with metal box motor drivers, and my caster wheel again.

    Carpet Monkey v4 rear view

    These claws took forever to CNC, had to make *too many* by hand . . .

    Carpet Monkey v4 claw design

    Carpet Monkey v4 claw design

    Carpet Monkey v4 claw design

    Carpet Monkey v4 claw design

    After this failure, I decided to never ever build a robot again without first fully calculating the whole darn thing. Math would have saved me tons of money/time!


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