Retrograde- Knex Ball Machine Instructions (Not My Design)

Introduction: Retrograde- Knex Ball Machine Instructions (Not My Design)

This is not my own design, this is MarsCrystalMans ingenious design and I made an instructable for him on this. This instructable is quite long so it may take a while to build. This instructable is not intended to be high-quality but good enough to be understood. 

video at

Step 1: Piece Count


Grey: 58
Red: 175
Yellow: 173
Blue: 403
White: 363
Green: 340


White: 78
Blue 3D: 134
Purple 3D: 255
Yellow: 255
Gold-track connector: 17
Green: 209 
Orange: 125
Red: 184
Light-grey: 67
Dark-grey: 244


Black Y-clip: 63
Tan-clip: 28
Gold-track clip: 14
Ball-socket joint: 2
Silver spacer: 79
Blue spacer: 132
Purple flexi-rod: 16
Orange flexi-rod: 7
Golden(red) rod: 8
Red gear: 1
Blue gear: 5
Large yellow gear: 1
Tan(red) rod: 7
Small triangle panel: 11
Triangle panel(3 holes): 3
Small square panel(1 hole): 1
Square panel(3 holes): 3
Small tire with tread: 11
Medium tire with tread: 5
Large tire tread(no tire): 2
small snap-on tire: 2
Medium snap-on tire: 1
Motor(newer green ones): 1

Step 2: The Base

Step 3: Support Structures and Return Tracks

A Big Step.

Step 4: Path Selectors and Drop-Path Selector

Another big step. This also fulfills a request for the Drop-Path separator for a member.

Step 5: Stepper- Lift System

This fulfills another request for a member. This is an instructable in an instructable!

Step 6: Path 1

I  found this element to be very cool.

Step 7: Path 2 ( Wormhole Element)

This path has the Wormhole Element someone wanted instructions on. Includes part of another path.

Step 8: Path 3

The path that traps the ball behind the wormhole.

Step 9: Path 4

This step may seem complicated but just copy what you see. I didn't feel like taking the whole thing apart. I used a tv jack cable for the tubing. I modified the element with spacers. The element didn't work for me for some reason, maybe because the cable was too thick so try roller coaster tubing.

Step 10: Path 5

This includes the spinning wheel element, a very clever piece.

Step 11: Path 6

This step includes the spinning basket element.

Step 12: Path 7

Just about done! This is the graceful turn that really makes this machine unique.

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    9 Discussions


    8 months ago on Step 10

    more instructions on the spinning wheel would help a lot
    that part is complex. but other than that i am looking through al lof the pieces iahve to see if i can build it
    but looks fantastic cant wait to start building!!!


    7 years ago on Introduction

    looks awesome! I'm going to build it but do I need 17 gold track connectors?


    7 years ago on Step 5

    up to this step waiting for big yellow gear o come from ebay then ill continue building the ball machine


    Reply 7 years ago on Introduction has yellow gears, you just trying to find one for a cheaper price?

    Good job, the instructions are very good. (And you just saved me a ton of time :-D). Also, I like some of your modifications; they enhance the machine, especially the spacers on the spiral, much better placeholders. One note: you said there is no video for the machine, but if you wanted, you could say "video at". That would cover it!
    Once again, great job! The instructable has my seal of approval! (Not that you needed it, but... ;-D)


    Reply 7 years ago on Introduction

    Thanks a lot :-D. I fixed the description so thanks for the tip.


    7 years ago on Introduction

    yes you made instructions i going to start building tommorow ,good job :-]