Skip to main content

1.1

Major VersionM

by Pete Prodoehl

Introduction

Who needs wheels to move around? We're going to add arms to our Rover and let it swim (or crawl) across the floor.

Video Overview

  1. For this guide you'll need a completed Rover Main Body. You'll also need some of the parts used for building the Tank and the Gripper.
    • For this guide you'll need a completed Rover Main Body.

    • You'll also need some of the parts used for building the Tank and the Gripper.

  2. Remove the wheels from the Rover.
    • Remove the wheels from the Rover.

    • They should pop right off!

    • You can store them with the other parts of the Rover Kit for now.

  3. Build the arm as shown by inserting two black pins into the large gear, then attaching the angled beam. Build the arm as shown by inserting two black pins into the large gear, then attaching the angled beam.
    • Build the arm as shown by inserting two black pins into the large gear, then attaching the angled beam.

  4. Next add the axle with end stop to the end of the angled beam. Finally, add the two smaller gears onto the axle.
    • Next add the axle with end stop to the end of the angled beam.

    • Finally, add the two smaller gears onto the axle.

    • The gears will help by adding some grip when moving.

  5. Build the second arm as a mirrored version of the first one.
    • Build the second arm as a mirrored version of the first one.

  6. Put the arms onto the servo shafts where the wheels were. Your Swimming Rover is almost ready to go. (We still need to add some code before it will move though.)
    • Put the arms onto the servo shafts where the wheels were.

    • Your Swimming Rover is almost ready to go. (We still need to add some code before it will move though.)

  7. If you've never used a micro:bit before you'll want to check out this guide:  Bit Board V2 Setup and Use
    • Power on the Rover and set it on the floor. (Carpet will work much better than a smooth floor, but it's time to experiment!)

    • The Rover should crawl (or swim) forward. Though not very gracefully!

  8. Hopefully your SwimBot went mostly straight. But... can you get it to turn one direction? Let's try!
    • Hopefully your SwimBot went mostly straight. But... can you get it to turn one direction? Let's try!

    • We can adjust things in two ways, either by adjusting the code, or by adjusting the physical build (in this case, the arms).

    • Let's look at the code first...

  9. Our original code just told the Rover to go forward for one millisecond, and then that command repeated over and over.
    • Our original code just told the Rover to go forward for one millisecond, and then that command repeated over and over.

    • Here is an example of a code change with turn left that could get your Rover moving with turns.

    • (The original code is shown on the left, new "turning" code on the right.)

    • We did not include the function to make the Rover go backwards because doing so just flips it upside down! (So that's an option if you want it.)

  10. Let's reload our original code that just made the SwimBot go forward. Done? Good! Now let's remove the arms and make some adjustments.
    • Let's reload our original code that just made the SwimBot go forward. Done? Good!

    • Now let's remove the arms and make some adjustments.

    • Try moving the pins from the first and second holes of the beam to the third and fourth holes.

    • Reattach the arms and give it a go! Is your SwimBot turning now?

  11. Want to take it further? One thing you can do is remove the caster wheel on the back of the Rover. See how it moves without it. You can also adjust the arms, flip them around, adjust the gears... Experiment! Alternately, leave your Rover as-is and make changes in the code. (Or make changes to both!)
    • Want to take it further? One thing you can do is remove the caster wheel on the back of the Rover. See how it moves without it.

    • You can also adjust the arms, flip them around, adjust the gears... Experiment!

    • Alternately, leave your Rover as-is and make changes in the code. (Or make changes to both!)

    • You can also adjust the speed in the code. How will that change how the Rover moves?

    • You might even try remotely controlling this Swimming/Crawling. bot!

    • See if you can find other ways to make a SwimBot (or CrawlBot) with the parts in your Rover Kit.

Finish Line

Pete Prodoehl

Member since: 03/04/2020

281 Reputation

276 Guides authored

0 Comments

Add Comment

View Statistics:

Past 24 Hours: 0

Past 7 Days: 2

Past 30 Days: 19

All Time: 146