The Gear Train of Doom

Sometimes it's fun to create something completely and utterly pointless. Then, after you create something pointless, you want to share it with the entire world, right? Maybe not. In any case, I want to properly display one of my great feats of uselessness: The Gear Train of Doom. The principle is simple. It consists of lots of sets of gears stacked against each other, such that the gear reduction reaches ridiculous levels.
This gear train uses seven 40-tooth-to-8-tooth pairings, and nine 36-tooth-to
12-tooth pairings, with a few 24-tooth gears in there for some reason.

Here are some stats:
  • The gear ratio is one billion, five hundred thirty seven million, seven hundred thirty four thousand, three hundred seventy five to one, or 1,537,734,375 to 1.
  • When driven by a Lego RC motor, which can operate at 3000 RPM, it would take two years and four months nonstop to finish one rotation of the output.
  • When driven by a Lego RC motor, the output has 20 million, 755 thousand, 396.46 foot pounds of torque, which approximately equals 27,131 Chevy Silverados. With that kind of power, one could easily snap the Empire State Building in half. (It would take decades, though).
  • When driven by a Lego NXT motor, it takes an abysmal twenty five years to complete a rotation, but has nine times as much torque as the RC motor.
  • Under no circumstances would you need to use this. EVER.
I built the Gear Train of Doom when I had spare time in shop class, out of the forgotten remnants of a few Mindstorms NXT's. I pretty much raided every gear in the box to build it. My gear train became quite popular among my classmates, and my teacher even mentioned it at a meeting once. (My shop teacher is awesome, by the way. You can find his YouTube channel here). The conversation went something like this:

Other Teacher: "I wrote this great new assignment to make students calculate gear ratios!"

My Teacher: "I have a student who does that for fun, except REALLY OVERKILL."

I think he almost passed out when I showed him all the numbers I calculated. In spirit of this, I encourage everyone to build something completely useless, as time well wasted is not wasted at all.


  1. you are correct. I will NEVER need this gear ratio. That is why it is so awesome!

  2. Love the name: Gear Train of Doom! It's awesome in its uselessness. Great post.

  3. Love that time well wasted is never wasted! Great post. I love the Gear Train of Doom.