Knex Bi-Directional Cart

Introduction: Knex Bi-Directional Cart

About: I'm into knex ball machine stuff. My favourite parts are lift/element hybrids, probably because I tried building a perpetual ball machine. It didn't work, of course. All my knex stuff is creative common, an...

I made a little car which changes direction whenever it hits a wall, using only one motor.

There a seven gears involved: 4 red gears, 2 yellow gears, and 1 blue gear.
The car is 1 grey rod long, 1 red rod wide, and 1 red rod high.

Step 1: Bottom Frame and Wheels

This is the bottom framework.

There are 2 axles connecting this frame which hold the wheels and the gears that turn in the same direction of the car. Having 2 gears is recommended, and a rubber band must be put on any wheels connected to a gear.

The framework isn't symmetrical.

Step 2: Main Axle

Here is where the magic happens.

At no time can both red gears mesh with the yellow gear. To achieve this, align a blue spacer next to the orange connector like in the fourth picture. You will have to readjust this when adding it onto the car.

Step 3: Top Frame

Build these for holding the motor... and aesthetics.

Step 4: Putting It All Together

First put in the Main Axle in between the bottom frame. The white rod (holding the yellow gear) slots into the yellow connector. It doesn't matter which way the other yellow gear points.

The top frame then is added. Make sure the yellow connectors from the main axle and top frame are on the same side.

Step 5: Motor and Done!

The motor holds a blue gear which meshes with the side Yellow Gear. Attach the green rods to the dark grey connectors and tighten this with the tan clips.

You're Done!

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    11 Discussions

    0
    s0200311
    s0200311

    4 months ago

    Amazing!

    0
    random_builder
    random_builder

    3 years ago

    The car is cool, and the instructions are ok. I tried to make this and it switches direction before it hits the bar

    0
    mathsboy314
    mathsboy314

    Reply 3 years ago

    Sorry for the late reply. Go back to step 2 and make the red gears further apart.

    0
    random_builder
    random_builder

    Reply 3 years ago

    I will try that soon.

    0
    www139
    www139

    4 years ago

    Should really be featured! :D

    0
    Lolman4000
    Lolman4000

    5 years ago on Introduction

    I could definitely use this gear system in one of my builds.