Author Topic: 11,000,000 : 1 Gear Ratio  (Read 3037 times)

Offline cfellows

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11,000,000 : 1 Gear Ratio
« on: July 06, 2015, 03:06:44 PM »
Those of you who like gears might enjoy this video...

<a href="https://www.youtube.com/watch?v=kYmUJVE6Vo0" target="_blank">http://www.youtube.com/watch?v=kYmUJVE6Vo0</a>

Chuck
So many projects, so little time...

Offline philjoe5

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Re: 11,000,000 : 1 Gear Ratio
« Reply #1 on: July 06, 2015, 04:19:18 PM »
I like it Chuck.  It would make a heck of a back gear on the lathe :lolb:

Cheers,
Phil
If you pick up a starving dog and make him prosperous, he will not bite you. This is the principal difference between a dog and a man.  - Mark Twain

Offline b.lindsey

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Re: 11,000,000 : 1 Gear Ratio
« Reply #2 on: July 06, 2015, 07:41:56 PM »
Well at a spindle speed of 3600 rpm and assuming the rounded ration of 11,000,000 to 1, using that as a back gear would yield one revolution approximately every 51 hours, but imagine the torque!!  I am wondering if that was machined from plastic or 3D printed. Hard to believe how compact it is too.

Bill

Offline philjoe5

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Re: 11,000,000 : 1 Gear Ratio
« Reply #3 on: July 06, 2015, 08:50:34 PM »
Gee Bill, at that spindle speed I expect I could manage single point threading :ROFL:

Cheers,
Phil
If you pick up a starving dog and make him prosperous, he will not bite you. This is the principal difference between a dog and a man.  - Mark Twain

Offline PStechPaul

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Re: 11,000,000 : 1 Gear Ratio
« Reply #4 on: July 06, 2015, 10:57:37 PM »
That reminds me of the James Bond wristwatch (or similar small device) that had a huge reduction drive to a cable that was strong enough to pull the bars from a jail cell or move a car (I forget exactly what it was). Perhaps this:
 
http://watchesinmovies.info/movies/moonraker-1979/

 
https://en.wikipedia.org/wiki/List_of_James_Bond_gadgets
http://twojb007.tripod.com/gadgets.htm
 
I may be thinking about the grappling hook, but I remember some show (perhaps not James Bond, maybe Get Smart?) with a little wind-up or electric winch that was enormously powerful. I think there is a practical limit to a reduction gear train where the losses will add up to a very high input torque. Couldn't find definitive information, but I think it's between 100:1 and 1000:1.
 
https://en.wikipedia.org/wiki/Gear_train
 
Some good information:
http://www.freestudy.co.uk/dynamics/gears.pdf
http://www.cs.berkeley.edu/~sequin/CS285/2011_REPORTS/CS285%20final%20paper_Eric&Jessie.pdf
http://www.neugartusa.com/Service/faq/Plratio.pdf (highest ratio for planetary gears is 10:1 per set)
 

Offline rklopp

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Re: 11,000,000 : 1 Gear Ratio
« Reply #5 on: July 07, 2015, 01:27:00 AM »
The Exploratorium in San Francisco has a cascaded worm gear reducer where, IIRC, the input shaft turns at 200 RPM, but the output shaft will take several times longer than the current age of the universe to go around once.

Offline philjoe5

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Re: 11,000,000 : 1 Gear Ratio
« Reply #6 on: July 07, 2015, 03:36:44 AM »
Paul,
In the Movie "In Like Flint" James Coburn had a grappling hook in a wrist watch.  Lots of improbable events take place in that movie.

Cheers,
Phil
If you pick up a starving dog and make him prosperous, he will not bite you. This is the principal difference between a dog and a man.  - Mark Twain

 

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