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I need your help. Simple Single Servo Robot — Parallax Forums

I need your help. Simple Single Servo Robot

Oldbitcollector (Jeff)Oldbitcollector (Jeff) Posts: 8,091
edited 2011-09-19 17:39 in Robotics
I've got some more goodies cooking on the back burner and could use some help.

I'm looking for some ideas for a single servo robot. Something reasonable simple that doesn't require too much engineering or additional materials.

An example would be the paper, puppet mouth that was on Hackaday a while back.

You guys got an ideas?

Jeff

Comments

  • WBA ConsultingWBA Consulting Posts: 2,933
    edited 2011-08-30 10:30
    You should be able to make a robot with a single servo by utilizing the "straight forward, reverse turn" method of movement used by super simple remote control toys for toddlers. Not sure how to do the mechanism that makes the wheel turn when going in reverse only, but should be easy somehow.
  • ercoerco Posts: 20,255
    edited 2011-08-30 11:22
    I like the idea. I bet some kind of tilt/stride biped could work in a properly-tune mechanical system.

    Let's get a contest going, Parallax can make the winner!
  • BamseBamse Posts: 561
    edited 2011-08-30 12:10
  • Beau SchwabeBeau Schwabe Posts: 6,559
    edited 2011-08-30 12:36
    OBC,

    Since I know that you are very much into the retro designs, how about a 2011 version of the Mattel Vertibird we all loved playing with as a kid, where the SERVO is directing the direction of the helicopter blades?
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2011-08-30 13:03
    This is an excellent challenge, OBC! I've often pondered the possibility myself. Now there's incentive to ponder it further!

    -Phil
  • ercoerco Posts: 20,255
    edited 2011-08-31 09:30
    Bamse wrote: »

    Genius! I'm mad I didn't think of it...
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2011-08-31 16:49
    How about making "something" (dowels with rounded ends, mounted to a base) to sit on the servo horn so that when that's placed in a paper bag (remember paper bags, anyone?), the lunch-sack sort, makes it look like there's something inside, moving around, trying to get out.
  • Beau SchwabeBeau Schwabe Posts: 6,559
    edited 2011-08-31 16:57
    PJ Allen,

    It's likely to get stepped on (squished) ... Have you ever picked servo out of your shoe? ... I don't imagine it would be pretty.
  • Martin_HMartin_H Posts: 4,051
    edited 2011-08-31 19:56
    A while back Erco posted a pointer to analog balance bot which used a single servo. It can only go forwards and backwards though.
  • ercoerco Posts: 20,255
    edited 2011-08-31 23:43
    Here's a 3-servo robot that walks, hops, sidesteps, fights, self-rights: http://www.youtube.com/watch?v=ej1_BWnmpgg


    If we can't get a (kinda sorta) biped robot to just walk & turn fairly well with 1 servo, then we suck. :)
  • ercoerco Posts: 20,255
    edited 2011-08-31 23:51
    And for even more Youtube one-motor, humanoid, walking, self-righting inspiration with more fantastic music, see http://www.youtube.com/watch?v=DPyHQPm6UwY :)
  • WhitWhit Posts: 4,191
    edited 2011-09-01 18:22
    It even tap dances...
  • ercoerco Posts: 20,255
    edited 2011-09-03 09:26
    Jeff: Got any bites? I have a few ideas, but no time!
  • GranzGranz Posts: 179
    edited 2011-09-19 17:39
    OBC,

    Not sure if this would qualify (since it has a regular DC motor as well as a servo, but it does have only one servo), but take a look at W. Grey Walter's Turtle (http://www.extremenxt.com/walter.htm). You could emulate one of these pretty easily with a single servo and one DC motor in a tricycle format.

    The article says that he used a two-vacuum tube computer, but I believe that it was really just an op-amp (think Solarbotic's Herbie - http://www.solarbotics.com/products/k_hm/). A Prop would be able to blow that away - with seven cogs tied behind it's back :tongue:

    Walter's Turtle used the "front" wheel as the drive, and steering, wheel and the two "rear" wheels as free-wheeling stabilizers; I would recommend using the servo to turn the front free-wheel for steering and the DC motor to drive the rear wheels.

    Also, as Beau pointed out, you do like your retro stuff; and this is pretty retro (over 50 years), so this should be right up your alley.
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