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Lego Compatible Servo — Parallax Forums

Lego Compatible Servo

Has anyone tried this before? I was hoping I could plug it into the boe-bot's P14 and 15 pins and do some fun activities with my class.

Thanks,
Diane

https://www.browndoggadgets.com/products/lego-compatible-360-degree-servo

Comments

  • Hello!
    Speaking for myself, not yet.

    Sometime last year I was working out the details to, ah, reproduce the basic BOE bot design using LEGO, both wheels, and a platform.

    But making the design work proved difficult.
    ---
    Erco, why are there two mountain lions examining your car?

    And why did a crowd of robots land on an island in Puget Sound?
  • Well I just ordered two. They'll be here in days. When I get them to work with the BASIC Stamp2 on the BOE, or a Propeller 1 rig on a PAB, I'll report it here.

    And if it works, they'll also include first photos of the bot.
    ---
    Mascot away.
  • Thanks for being the guinea pig!
  • ercoerco Posts: 20,244
    Interesting. I'm not convinced that that particular form factor is the most flexible for LEGO use. The guts appear to be a more-or-less standard 9 g CR servo. I'd rather see the dots & holes on the 4 or 5 big flat sides of the servo. You could roll your own by using those adhesive LEGO-compatible rubber strips. And of course the actual wheel choice and connection method would make or break the system.

    Another curious find on that site is a uC board that has LEGO-size holes on the PCB, along with "conductive Maker tape". There's a chance that may actually be more difficult than using plain old wires, but I do like the thinking. At a glance, it LOOKS modular. https://www.browndoggadgets.com/collections/new-crazy-circuits-chips/products/crazy-circuits-robotics-board

    A simple BoE-style breadboard is pretty flexible. Seems like a LEGO-based construction system with a modular breadboard system (done properly) could be successful.

    There's an Australian (maybe Kiwi) LEGO-compatible orange robot chassis called Edison which already has a sizeable educational following in schools. https://www.amazon.com/Contempo-Views-Edison-Robot-2-0/dp/B01HSFMK6G



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  • erco wrote: »
    There's an Australian (maybe Kiwi) LEGO-compatible orange robot chassis called Edison which already has a sizeable educational following in schools. https://www.amazon.com/Contempo-Views-Edison-Robot-2-0/dp/B01HSFMK6G



    I use Edison robots in my 5th/6th grade class. It's a good intro product, but its limitations are frustrating. The kids really like it.
  • Buck RogersBuck Rogers Posts: 2,160
    edited 2020-12-22 22:15
    Hello!
    Well both of mine arrived today, five days late as it happens. It turns out they resemble a pair of regular servos that I obtained from when RS was collapsing. [Think of the box of intended things to be used with the other platform that's also supported by the Shield Bot that's sometimes intended to enable the builder to try out ideas before committing to a final design on that platform.] @erco you suggested that they resembled 9g servos, well so are those.

    When the two arrived, I checked to see if they were a good fit for the wheels I had in mind. They were not. So these two are now being used, or will be used, for, ah, model management.
    --
    Oh wow. Erco there's a soggy mountain lion looking through your garage for a towel.
  • Buck RogersBuck Rogers Posts: 2,160
    edited 2021-04-04 18:46

    @bmcnicho said:
    Has anyone tried this before? I was hoping I could plug it into the boe-bot's P14 and 15 pins and do some fun activities with my class.

    Thanks,
    Diane

    https://www.browndoggadgets.com/products/lego-compatible-360-degree-servo

    Update!
    I have both of mine plugged into one of the BOE boards, and they are wearing construction wheels and improvised Lego axles. Running the program for running a CR servo:

    ' RotateParallaxCrServo.bs2
    ' {$STAMP BS2}
    ' {$PBASIC 2.5}

    counter VAR Word
    servoPin PIN 14 ' change I/O pin for servo signal here

    FOR counter = 1 TO 100 ' Rotate counterclockwise for ~3 seconds

    PULSOUT servoPin, 850
    PAUSE 20

    NEXT

    FOR counter = 1 TO 100 ' Hold still for ~3 seconds

    PULSOUT servoPin, 750
    PAUSE 20

    NEXT

    FOR counter = 1 TO 100 ' Rotate clockwise for ~3 seconds

    PULSOUT servoPin, 650
    PAUSE 20

    NEXT

    END

    Currently it is showing P14, which was the last test. I basically saw the wheel turn. I'm going to build that Board of Ed Bot out of Lego.

    Mascot is away.

    Erco if you're monitoring this thread, the mountain lions left.

  • And worse luck it did not work. These servos can not be used to spin wheels attached. These servos could be used for spinning and pulling around Lego models, but not robotry.

    For those we'd need to figure out how to adapt the real ones.

  • @erco said:
    I'd rather see the dots & holes on the 4 or 5 big flat sides of the servo. You could roll your own by using those adhesive LEGO-compatible rubber strips. And of course the actual wheel choice and connection method would make or break the system.

    It's even worse because it seems the dots/holes that ARE on the servo don't actually mesh with Lego bricks. Maybe the sourced servos were meant to mesh with a 'Chinese Lego' system or something. However, mounting the servos with PIN connections, works perfectly. And PIN connections are superior to stacked connections anyways.

    I'm having an absolute blast with my servos. They enabled me to combine two toys into one (R/C and legos)

  • @The_Master said:

    @erco said:
    I'd rather see the dots & holes on the 4 or 5 big flat sides of the servo. You could roll your own by using those adhesive LEGO-compatible rubber strips. And of course the actual wheel choice and connection method would make or break the system.

    It's even worse because it seems the dots/holes that ARE on the servo don't actually mesh with Lego bricks. Maybe the sourced servos were meant to mesh with a 'Chinese Lego' system or something. However, mounting the servos with PIN connections, works perfectly. And PIN connections are superior to stacked connections anyways.

    I'm having an absolute blast with my servos. They enabled me to combine two toys into one (R/C and legos)

    Hello!
    I beg your pardon? When I worked on my last activity, I found that I was able to snap the servos I chose onto blocks. And when they first arrived I was able to attach them onto different blocks in various positions. Incidentally the company name is capitalized, as Lego. And is its own plural word, Lego becomes Lego when talking about a heck of a lot of them.

    Now as for their interesting ideas of the "maker tape" stuff, and their breadboard on Lego ideas, that's next. I'll probably include a Parallax designed controller into the mix.

  • @"Buck Rogers" said:

    I beg your pardon? When I worked on my last activity, I found that I was able to snap the
    servos I chose onto blocks.

    I stand corrected. I was trying to stack them up the wrong way LOL

    We are using the servos to make 'Lego Battlebots'. The torque and speed of the continuous rotation servo is adequate for creations of typical Lego size. The torque of the regular servo is adequate as well.

    We are running continuous rotation servos through a gear train before it gets to the drive wheel. I assume others are correct that the servo alone cannot support a drive wheel axle.

    No offense to BOE bot, but I can't imagine it doing anything close to what a homemade Lego creation that fits into the palms of your hand can do. I mean we are doing 4WD, differentials, conventional steering, tank steering, weapon systems, cameras etc. For a $100 you can buy a decent amount of Mechanic Legos on ebay, and get just parts you actually would want

  • Lego Battlebots showing strength of the Lego compatible micro servos.

    Maybe my transmitters outputs need to be scaled (ie transmitter needs programmed) and the servos would be stronger perhaps

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