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Extreme Reduction Gearing Device Offers an Amazing Gear Ratio

Posted by samzenpus on from the switching-gears dept.

ErnieKey writes: The 3D printed extreme reduction gearing device, created by long-time puzzle maker M. Oskar van Deventer, may leave you puzzled for its obvious applications, but the coaxial cranking mechanism offers potential in a variety of real-world applications with multi-colored gears that move in opposite directions at a ratio of 11,373,076 : 1. This 3D printed reduction gearing device is compact and multi-colored, and looks deceivingly simple at first glance. Developed through a complex algorithm, it could possibly offer potential as parts for machines like 3D printers, aerospace and automotive components, as well as perhaps robotics and a variety of motors.

8 of 148 comments (clear)

  1. it could... by drinkypoo · · Score: 5, Insightful

    it could possibly offer potential as parts for machines like 3D printers, aerospace and automotive components, as well as perhaps robotics and a variety of motors.

    Correct me if I'm wrong, but wouldn't that much reduction be fairly pointless? Wouldn't you basically have to make it out of unobtainium (the high-torque parts, anyway... most of it, that is) in order to do useful work with it?

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    1. Re:it could... by serbanp · · Score: 5, Insightful

      I once built an extreme gear reduction (3600rpm to 0.1rpd - d stands for "day") using ordinary plastic gears. The target use was to demonstrate pulling a salt mono-crystal from a saturated salt solution. No high torque, just a veeeery slow motion needed.

    2. Re:it could... by Anonymous Coward · · Score: 4, Insightful

      The weight of the fridge, transferred via the rope and pully, will rip the gears clear off the end of the shaft and tear this 3D printed device apart.

      As the GP was getting to, the multiplicative effect of the gearing on the torque is only useful if the structural strength is there to match.

      A car analogy applies to rev heads fitting low-geared diffs and transmissions to their cars, to only find they do stupid things like twist the chassis out of shape or rip bearings or thrust spindles apart!

    3. Re:it could... by Bing+Tsher+E · · Score: 3, Insightful

      The 9v battery would have to be changed very frequently.

      Anyway '9v battery' analogies and references are now obsolete. Have you noticed how expensive those freaking things are now? All modern designs have switched to batteries made out of a few AA cells.

  2. Exponential does not just mean "a lot" ... by Anonymous Coward · · Score: 3, Insightful

    It has a very specific meaning and the way it is used in this article is not it. Sorry, pet peeve.

  3. I call BS on the pracitical applications. by petermgreen · · Score: 4, Insightful

    TFA seems to conflate the ideas of speed ratio and force multiplication. That is only true if the mechanism is perfectly efficient. In practice some of the input force will instead be consumed opposing friction in the mechanism and the output force will be limited by the stretch of the parts. So the maximum force multiplication achived may be substantially lower than the speed ratio.

    To make a high ratio gearbox practical for force multiplication the low torque high speed parts need to be small to minimise friction while the low speed high torque parts need to be large to prevent them from breaking.

    To make it practical for accurate rotational positioning again the low speed parts need to be large, otherwise flexibility in those low speed parts will compromise the ability to accurately maintain position.

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  4. Re:Missing something by Anonymous Coward · · Score: 3, Insightful

    The "special" part is that it's 2 planetary sets driving a third acting as a coaxial differential, *not* a long chain of reductions.

  5. Re:Missing something by Required+Snark · · Score: 5, Insightful
    So if you're such a genius, what have you done recently that's as creative as this? (Sound of crickets...)

    Did you bother to look at the video and see how he worked out the gear ratios? With a relatively small number of gears he managed to have a one in the denominator of the ratio equation and at the same time he made the numerator be 11,373,076. A design with those properties doesn't leap off the page the first time you try it. It's really hard.

    He said it was compact for the extreme ratio. I'll bet if you tried to do something similar it would be a lot bigger, need a lot more gears, and might not even work. Care to prove me wrong? (Hint: no combination of worm gears comes even close.)

    You're just another Slashdot Pundit, living in your parents basement and sneering at people who get stuff done in order to make up for the fact that you're utterly useless. Anyone with a life would never make such a stupid comment.

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