Introduction: Leapfrog Separator, a Knex Ball Machine Path Separator

About: Hey! I'm Sandroknexmaster. I like building with knex, especially ball machines. I live in Belgium. I speak Dutch, but also English and French. I hope you like my stuff, and like always comment, rate & …


This are the instructions for the Leapfrog Separator. It was first used in my ball machine Elysium.

The separator used in the instructions takes 5 balls, but you can make it as long as you want.

Some flexi rods are added because they look good on the separator, but they are not required to make the mechanism work.

If you're going to build this separator, don't forget to read the image notes!

Thanks for watching / building!


Step 1: Piece Count

If you want you can count the pieces before you start building.

Here is a list with all pieces included in this separator, named by their original colour:


Green: 94

White: 32

Blue: 100

Yellow: 12

Red: 20

Grey: 2

Long flexi: 10

Total rods: 270


Dark-grey: 18

Light-grey: 8

Red: 29

Green: 28

Yellow: 68

Purple: 92

Blue: 12

Total connectors: 255


Blue spacer: 2

Silver spacer: 14

Y-clip: 2

Total other: 18

Grand Total: 543

Step 2: First Module

This is the first module, we need to build it once.

Step 3: Last Module

The last module, we will also need it once for the separator.

Step 4: Middle Module

Now you can choose how long you want your separator to be. You can build this module as many times as you want. In the instructions, three middle modules are built. Together with one first module and one last module, that makes five modules and thus five balls can be separated by this separator. You can choose to add more, less or even none, then the separator will be able to separate two balls (only first module and last module).

Step 5: Support

If you chose to make three middle modules like in the instructions, you can use these support pieces to finish your separator in the next step. If not, you will have to improvise and make your own support parts, it shouldn't be too difficult.

Step 6: Combining All Modules

In this step we will combine all the modules. If you have five in total, you can also add the support parts from the previous step.

Step 7: Flexi Rods

This step is optional. Use some flexi rods to give a finishing touch to your separator!

Step 8: Finished!

Your Leapfrog Separator is finished!

Thanks for watching / building!


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