K'nex Combination Lock




This is DarthVader giving you a combination lock and my second instructable!

EDIT: wow, its been a while. my friend asked me to tell you guys that this is not my lock, i posted it for my friend a while back. this and the grabber. sorry, i didnt know he would ever be on this website, and i didnt know anybody even cared still lol, but apparently ppl still do! but yeah, this isn't mine. i just took the pictures.

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: Wheels

These are essential to the combination lock!

Step 2: The Pin

This isn't essential, but it does add to the combination lock. Without it, your combination lock is a lot more dull... You'll see what I mean when you finish. Hinges work much, much better than ball socket and ball joint combinations! Try using older ones, as newer hinges tend to stay in the same position, whereas older hinges are more affected by gravity, being worn down and all.

Step 3: The Side Plates

These keep the combination lock together. Build 2.

Step 4: Connections

Connect the wheels to a rod, add spacers, and add to the plate. Connect the pin to the plate. The spacers in the second picture to the wheels (plate to end of yellow, or left to right): One, four, four.

Step 5: Add Second Plate and Customize

Add the plate and customize the wheel and the lever (for the pin). I used tan connectors to hold the yellow rods in place on the back.

Step 6: How to Make It Work

I don't own a video camera, so I can't post a video, but I'll try to explain how to set up your combination lock as best I can: You know those ball sockets on the green connectors? You rotate one on each white connector so that it interlocks with the ball socket on the wheel next to it. The middle wheel will require two ball socket rotations because there are two wheels next to it. Also, make sure that every single space (Green rod with no ball socket attatched) is lined up first, or else it will be pointless. Hope that helped! If anyone understands this and has a video camera, please demonstrate. Thank-you!

Be the First to Share


    • CNC Contest

      CNC Contest
    • Teacher Contest

      Teacher Contest
    • Maps Challenge

      Maps Challenge

    122 Discussions


    Reply 10 years ago on Introduction

    uhh how about you make it a little bigger, make the wheels squares made from white rods and red connectors, -1 rod on one side of each wheel.. would that work, do you think??


    Reply 8 years ago on Introduction

    I built it, he posted it. That wouldn't work because it would be too bottom-heavy, I tried it. It's a shame a video was never put up.


    Reply 8 years ago on Introduction

    i don't know what you tried but i saw many people do square tumblers that worked. anyway, check out my safe (ASKUS) for a real knex safe with big wheels and an actual safe to go with the tumblers and pin.