Knex Programmable Rod V2




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...

This is a smaller version of my Programmable rod.

You program it by changing the pins on the chain. Every time a pin passes a point, the direction of the output rod changes.

The chain design was inspired by TheFoofinator. Check out his programmable vihicle!

Here is a video of the machine in action:

Step 1: Frame

There are 6 silver spacers on the red rods.

Step 2: Pair of Yellow Gears

These yellow gears will slide onto the red rods.

Step 3: Output Rod

The big gear on the output rod should mesh with the bottom gear from the previous step.

Step 4: Driving Axle

All of these pieces fit on the grey rod. These pieces are:

  • Tan clip (on tip)
  • Blue spacer
  • White connector
  • 2 Silver spacers
  • White connector
  • Blue spacer
  • Tan clip
  • Yellow gear
  • Blue spacer
  • White connector
  • Silver spacer
  • 2 Blue spacers
  • White connector
  • Silver spacer
  • 2 blue spacers
  • Tan clip
  • 2 Red Gears
  • Tan clip
  • 2 blue spacers
  • Silver spacer
  • White connector
  • Silver spacer
  • Blue spacer
  • Tan clip (on tip)

Step 5: Attaching the Driving Axle

Step 6: More Frame

Step 7: Alternator

This part controls the director of the output rod.

Step 8: Detector

This is the combination of a crankshaft, and a very unusual gear with two teeth.

Step 9: Attaching the Detector

The Y-clips will clip onto the red rods. Once you're finished building, you will have to slide the Detector up and down the red rods to find the best position for it to be in.

Step 10: Motor Rod

This rod will hold the motor and the chain.

Step 11: Weight

This holds the gears in position.

Step 12: Programming It

Every time an orange connector passes the detector, the output rod changes direction.

Connect the orange connectors to the chain using a Y-clip.

In the example I gave, 25 chain links are needed.

Step 13: Finished

You still need to add a motor and move the detector.

I find that the gears slip quite frequently. If anyone knows a solution please tell me.



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    5 Discussions


    2 years ago

    Hello mathsboy314! Welcome back man. It's been a long time since you posted the Eater Automation Instructable and honestly, i liked it a whole lot.

    See ya!


    1 reply