1:1024 Planetary Gear Reduction

Saw a viral video somewhere of compounding gears ( Machine with Concrete - Arthur Ganson - YouTube ). The gear reduction was so great that the last output of the last gear was into a brick, yet the gears kept spinning and spinning. I didn’t go quite to that extreme, but I thought that was a really cool visual so wanted to do my own thing.

Thanks for looking!





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I love this! Thanks for sharing.

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So cool!

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A good toy for any engineers desk

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This is fantastic. Loved that you used wood and acrylic.

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Very nicely done!

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I made a gearset for a project a while back and found that involute gears weren’t great in acrylic because they would break at the root under load. I used round-tooth gears instead:

These gears could get much smaller in acrylic and take much higher loads. They also operated more smoothly than involute gears.

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Thank you much for sharing this! I wasn’t aware this was a thing

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That is really neat! I keep wanting to do something with gears, just because they look so fun to play with. What do the numbers on the side mean?

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Hey thanks! Each number is the compounding reduction. Layer 1 is 1:4. So 4 turns of the crank = one revolution.

2 layers is 1:16. So 16 turns of the crank = one revolution of the second ring.

Each ring is a 1:4 reduction so very quickly the numbers become huge. For instance if I doubled the rings to 10 this would become 1: 1,048,576

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This is really cool! Thanks for sharing both photos and video.

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Oh, okay! Thanks for explaining it for me!

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That is very cool indeed. I loved seeing it in action. Thanks!

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Well now that’s just cool!

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Thank you for the videos! Looks like a fun project. Nice desk or coffee table gift.

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Of course, you’re multiplying torque as well as reducing speed.

You should do something useful with that torque, like making an output stage that cracks nuts or something. With a 1:1024 stepdown, an ounce of torque at the crank would produce 64 pounds of torque at the output. :slight_smile:

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I did think about that! I suppose I thought putting acrylic through those kind of forces would make it explode lol

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It will depend on how you distribute the forces. It isn’t the force so much as the contact pressure that will kill the acrylic. If you can distribute the force over a larger area (lower contact pressure) you can transmit the force effectively. Laminated gears would help with this, as would offsetting the teeth on a laminated gear, creating a crude helical gear that will help distribute the force over more contact points.

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There is also, of course, thicker Acrylic. :slight_smile:

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Yes, though you really reach a limit on the thickness quickly with the GF because of the angle of the cut face. It would be better to cut thinner pairs and laminate them so the cut edge angles cancel each other. Plus lamination allows offset teeth and you get more benefit than just extra strength.

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