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Erco's Figure Eight Challenge

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  • Feel free to do so, the low center of gravity and high pivot point works pretty well to keep all the wheels on the ground.
  • From your previous video I could see that the rear axle can rotate. Your third image with the chassis skeleton make clear why.
    Very nice design!!!
  • NikosGNikosG Posts: 705
    edited 2015-10-30 17:04
    .
  • Thank you. I don't want to step on anybody's toes and take more than my fifteen minutes, but here is another video that shows it better. I have a video of the bot on a gravel pile roaming with ping, I can't seem to find it.

  • And to think that I have been whining about the 'Carpet to Tile' transition challenges,
    You have raised the bar considerably with the new 'Tile to Pillow' transition challenge...

    Nice work! and don't worry about taking up more than 15 minutes, That rule was dropped long ago.. :)


    -Tommy
  • Thanks Ttailspin,
    These servos are Parallax-Fatuba, and with the sticky tires, will climb up a wall if the tires were sticky of enough. Upgrading to high torque servos should prove significant performance.
  • ercoerco Posts: 20,256
    edited 2015-10-30 22:39
    I really like that independent servo steering. On a big rubber tired bot, you can customize the effective Ackerman angle to reduce scrub for different situations, as in Mike's Figure 8 video demo where he pivoted about each inside rear wheel.

    Instantaneous centers rock!
  • erco wrote: »
    I really like that independent servo steering. On a big rubber tired bot, you can customize the effective Ackerman angle to reduce scrub for different situations,

    Ok would that be associated with RPM and the effect a turn has on servo ratio.
    Or do I just need an alignment?
  • ercoerco Posts: 20,256
    Lots of variables, angle and RPM. You could make a lookup table or do trig on the fly. Your front wheels will usually be steered in slightly different directions, based on track (width), contact patch size/shape, and center of rotation. Of course with those large wide inflatable (?) rubber tires, some scrub is inevitable no matter how anal you (I) want to get. As with most problems: when in doubt, add more power!
  • If I decided that I needed better resolution in control, and went proportional with steering and throttle, I would need that math on the fly, or lookup table. Rather than presets derived from obserations made on a stand. I have to leave that to you scientists, mathematicians, and seasoned programmers.
  • ercoerco Posts: 20,256
    Well it already works great, and it's the most exciting bot we've seen in ages! As you can tell from the numerous replies, we're all eager to see more. What's next? And your awesome bot certainly deserves a name so we can refer to it properly. :)
  • MikeDYurMikeDYur Posts: 2,176
    edited 2017-04-19 14:40
    Thanks erco, and everyone else.
    I am working on an acronym, not a variety of letters yet.
    I posted a new video that might interest you.

  • mike to erco,

    Do you think this has any merit? It probably has too many references to motion. Happy to ponder suggestions.

    T errestrial
    E xplorer
    M obile
    P ropeller
    P latform
    E nvironmental
    R over
  • Ok if no one minds, I'm going to drop one of the P's, and include it as Propeller-platform, and go with TEMPER. Next I want to plug in the long range radios, and go outside for some real world tests, I have to clean up the yard first, sticky pine cones and sticky tires don't mix.
    This is still "Erco's Figure Eight Challenge"
  • ercoerco Posts: 20,256
    Temper Fi!
  • MikeDYurMikeDYur Posts: 2,176
    edited 2017-04-19 14:40


    Since it was quiet, I thought I would put this on here, It gives a better look at the backbone of Temper.

  • ercoerco Posts: 20,256
    edited 2015-11-01 22:07
    Nice, are you manually driving it here?

    Dude, do a figure 8 over a book and you will own that category for many, many years! We're all flatlanders here.
  • ercoerco Posts: 20,256
    edited 2015-11-01 22:08
    erco wrote: »
    Dude, do a figure 8 over a book and you will own that category for many, many years!

    Bonus points if the book title has anything to do with robots or figure 8s. :)
  • Maybe I wont go out just yet.
  • Erco,
    I am running with RC tires with foam inserts.
    And I was in another room with a circuit on the PPDB, I do better with FPV. I need to create a new deck for the electronic's. Battery's are good ballast.
  • Does anyone remember the toy Mighty Mike?
  • ercoerco Posts: 20,256
    MikeDYur wrote: »
    Does anyone remember the toy Mighty Mike?

    Got mine right here. Need a Fat Cat pretty bad.
  • I had the traler and bridge, that brings back young memories.
  • ercoerco Posts: 20,256
    edited 2015-11-02 02:48
    I have the balancing Mike.

    This nice Fat Cat will surely top $300, maybe closer to $500. That would bring back my childhood past at great risk of shortening my future!

    http://www.ebay.com/itm/331695027901
  • Don't remember that one, I had a G I Joe set about the same scale, what were it's capabilities?
  • ercoerco Posts: 20,256
    MikeDYur wrote: »
    what were it's capabilities?

    CAT= Climb Action Traction, could go straight up walls, just like your bot! :)

  • WhitWhit Posts: 4,191
    Great project MikeDYur!
  • Whit wrote: »
    Great project MikeDYur!

    Thank you Whit,

    Erco, There were great toys back then,
    I would like to find a Mighty Mike NIB.
  • ercoerco Posts: 20,256
    MikeDYur wrote: »
    I would like to find a Mighty Mike NIB.

    It's only money!

    http://www.ebay.com/itm/Treacherous-Camelback-Skyway-6FT-Long-Playset-Swings-/390216875749

  • Erco Ouch,

    there maybe some other things that I would rather have. Thanks for the link, can't wait to see it on the computer.
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