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Forum: Feature this!
 Topic: Extreme Reduction - 11 million to one gearing by OSKAR
Extreme Reduction - 11 million to one gearing by OSKAR [message #118619] Sat, 04 July 2015 08:22 UTC
avatar Oskar_van_Deventer  is currently offline Oskar_van_Deventer
Messages: 445
Registered: December 2008
Go to my shop
Senior Member
Hi Non-Twisty Puzzles fans,

Extreme Reduction is an ultra-compact gearing system with an extreme reduction. The gear ratio is 11.373.076 : 1, that is, over eleven million to one!!! That extreme reduction is achieved in three stages.
-Stage 1: Two sets of planetary gears with a reduction of 24 : 1 and 25 : 1, respectively.
-Stage 2: Two subtractions, 26×26-25×27=1 and 25×25-24×26=1, respectively.
-Stage 3: Another subtraction, namely (25×26+1×25)-(24×27+1×26)=1.

The gear ratio of this mechanism scales to the 5th power with the number of gear teeth. That is, for ×2 times the number of teeth, you get ×32 times the gear ratio. Here are some exaple gear ratios:
-Teeth = 4, gear ratio = 2.185
-Teeth = 9, gear ratio = 87.220
-Teeth = 16, gear ratio = 1.322.209
-Teeth = 25, gear ratio = 11.373.076
-Teeth = 36, gear ratio = 67.320.649
-Teeth = 49, gear ratio = 305.880.100
-Teeth = 64, gear ratio = 1.141.624.705
The number of teeth of a gear needs to be an integer square plus or minus one because of the subtracting mechanism.

Whereas high reduction radios are typically achieved with worm gears, a planetary gear system like this is much more compact. The gears have a limited number of teeth, which makes the system very robust. Also unlike worm gears, this planetary gears system is coaxial, which makes it easier to place.

The application of this type of extreme reduction gears is unclear. A patient person could use it to move a heavy train locomotive with a dental dril.

Watch the YouTube video.
Buy the gears at my Shapeways Shop.
Read more at the Non-Twisty Puzzles Forum.
Check out the photos below.



Forum: Bug Reporting
 Topic: 524 error preventing purchase of models
524 error preventing purchase of models [message #118616] Sat, 04 July 2015 05:26 UTC
avatar rebeleer  is currently offline rebeleer
Messages: 4
Registered: January 2014
Go to my shop
Junior Member
For the past 24 hours I have been experiencing an issue with accessing my shopping cart. I have been trying to purchase my own models and anytime I try to access my cart to checkout I am getting a 524 error "Website is offline". CloudFlare says everything is alright on my end and that the problem is coming from Shapeways' host.

This is incredibly frustrating especially considering that I can access the cart when I am not logged in and other pages of the site for the most part. Every now and then though, they will take a long time to load and I will get that 524 error.



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