500 to 1 Ultra-Compact Gear Ratio

I recently designed a gearbox so I could break the world record. I then designed this in order to show and explain the principals at work within the mechanism. The design is infinitely stackable, meaning that if you were to continue printing these, you could theoretically make an insanely large gearbox.

the design uses (4x) ¼-20 screws to hold everything together.

What you need for the first stage:

• Crank
• Crankside cover
• First Sun Gear
• Planetary gear
• Inner grinder gear
• Outer grinder gear
• Rotator
• Inner sun gear

Assembly:

1. put the first sun gear through the crankside cover and press the crank on to the end of the first sun gear.
2. place the inner grinder gear inside the outer grinder gear. the planetary gear then goes inside of the inner grinder gear.
3. place the two assembles together so that the sun gear meshes with the planetary gear. Note that the top of all of the gear teeth should be flush against the crankside cover.
4. press the inner sun gear into the rotator so that the teeth are facing the opposite direction of the 4 “pips” on the rotator. 
5. place the rotator (pips in) into the small recess of the outer grinder gear. The pips should go around the arms of the inner grinder gear. This should lock the rotation.
6.  place the backside cover on so that the rotator cannot fall out.

If you plan to continue the gearbox:

1. After you have completed steps 1-5, instead of putting the backside cover on, put another outer grinder gear on. Then repeat steps 3-5.

Other notes:

!!!The output rotates in the opposite direction as the Input!!!

I've included a pointer that replaces the inner sun gear so that you can better ss the rotation of the output