K'nex Oblivion Ball Machine Instructions




Someone challenged me in a comment on the previous ible that I should make bigger ball machines so here it is! The Oblivion ball machine has one unique element and that is the automatic drawbridge or path 1. The bridge starts when the ball hits a switch and starts to lower. Then, a second motor will kick in and pull the mother switch back up making the bridge raise and then the bridge will shut the main motor off. This element I think was on another ball machine but I reinvented it to suit the newer motors. The first video shows the drawbridge element by itself. Credit goes to Shadowman39's motor switch mechanism in video one.

Step 1: Piece Count


grey: 94
red: 196
yellow: 458
blue: 878
white: 401
Green: 778


white: 97
blue 3d: 265
purple 3d: 603
yellow: 452
green: 24
red: 314
orange: 110
light-grey: 14
dark-grey: 209


orange track connector: 159
Black or tan rod: 3
Purple flexi-rod: 22
orange flexi-rod: 3
tan lock: 19
blue clip: 25
Y clip: 78
blue spacer: 113
silver spacer: 129
track clip: 6
medium tire no tread: 11
small tire: 4
red gear: 6
small blue gear: 1
yellow gear: 1
motors: 3
triangle panel with three holes: 1
chain link: 142


Step 2: Base and Supports

Let's start building!

Step 3: Return Path

Step 4: Main Support and Lift

Step 5: Secondary Supports

Step 6: Path Selecters

Step 7: Path 1- the Drawbridge

This step really isn't step-by-step based because I just put in a lot of pictures of the thing but I assure you you will be able to make it from them. There are four pulley systems and one mother switch. The process of the cycle goes like this:

1. The ball hits the mother switch and the bridge starts to lower down.
2. The bridge being at the bottom triggers motor 2 which is only there to pull the mother switch up which makes the bridge rise.
3. The bridge rises until the pulley in the back pulls the mother switch back down into the off position. Motor 2 automatically shuts itself off.

Yes, I give credit to the member who made the "Leave Me Alone Box" because motor two uses the exact mechanism.

Take your time with this, it is very easy to lose track of where you are. The pulley systems will take a little while to adjust so don't get impatient with them.

Step 8: Path 2- the Wheel

This path contains the large wheel at the center of the machine.

Step 9: Path 3- Double-Path

This path includes a new element that isolates the balls and spaces them farther apart.

Step 10: Path 4- Yin-Yang



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    29 Discussions


    6 years ago on Introduction

    Very cool! I see some inspiration i'm getting from you! I plan on using that double ball arm from ionization in my current ball machine. Maybe you could try making a knex ball machine elements guide to bring your elements you've made so far into one place, as well as redesigns of others you've made also (and have updates)!!

    Wait a minute...Sandroknexmaster and I only suggested you go bigger last week. You figured out the drawbridge mechanism and the whole caboodle in that time?! ;-D
    Great job, this machine is really cool! I really like the drawbridge element; I have tried something like this before but never got it to work. Between you and Shadowman39 I'll have to learn the art of mechanical automation!
    So keep it up with your machines and let us have some more innovations! Now you see why bigger is more fun? ;-)


    6 years ago

    Very unique ball machine. I had to build a drawbridge like that for an engineering class out of knex.


    3 years ago

    What is the difference between the dark gray and purple 3D connectors? The purple look exactly like the 3D dark gray connectors.


    3 years ago on Step 7

    iis there any way that you can show all of the hookups for the 2 motors you don't get a good view of the inside of the machine by the motor its very frustrating if you could please just show me the way the on off mechanism works thank you tim

    1 reply

    5 years ago on Introduction

    can you post more pictures from inside connection for the motor that is on the middle of the drawbridge step 7 its hard to see the inside parts, THANKS

    Well here it is... just remember you asked for it.... It took me 3 days to get that bridge to work.... Here is a free tip for those who wish to build this machine or use the draw bridge element.... Don't use stretchy string...


    6 years ago

    I'm working on the machine and I'm in the drawbridge step right now. I can't get the bridge to start motor 2 all the time. Any suggestions?

    1 reply

    For me it was just luck of it working. Is the string through the connector hole? It takes a lot and I mean a lot of tweaking for something like that so patience for something like that is needed. I'm really happy that you are building my machine!


    6 years ago on Introduction

    Great job mate in such a short time frame, truly awesome!

    This is one epic big ball machine, challenge completed :D
    I really like the drawbridge element, very cool invention.
    BTW, is it named after the film?