This cute little puzzle made by Bittorrent co-creator Bram Cohen features three interlocking gears that can only freely rotate in one configuration.

TriGears is a special puzzle. There are three gears set so that turning one gear turns the other two. If the three gears were in a flat plane they would, of course, jam. Oskar had the gears bevelled and set them at 60 degrees so that they all mesh in the middle. This apparently has no practical value and would not be a puzzle if Oskar had not made the teeth of the gears of varying width and of varying spacing. The object of the puzzle is to place the three gears in their holder such that they spin freely and do not jam. There is only one way to do this (see the solution). All other assemblies quickly jam. Once solved, the puzzle becomes a toy in that it is very satisfying to keep spinning the gears.

I’m not sure if it’s $425 worth of puzzle. especially not $425 worth of plastic.

I think he’s just mad that noone clicked the “donate” button in those early bittorrent releases.

What goes around, comes around and around and …

It is pricey because it is produced with a 3D printer, which has high (very high) materials costs.

Take that, Doktor Sleepless.

But surely there are only 48 combinations?

(3 options for the first gear, 2 different ways x 2 options for the 2nd gear,2 different ways x 1 options for the last gear, 2 different ways = 48 … assuming that the gear positions are different)

So solving the puzzle is simply trying each combination .. say 10 seconds for each attempt .. which means this will keep you entertained for about 8 minutes.

So the cost of the puzzle comes out at about $53 per minute of entertainment.

Wow. $53 a minute.

Mac

it reminds me of a 4WD transfer joint

Four hundred and wahhh?? That’s damn pricey for a bit of plastic gearing. There are many many much more interesting and beautiful puzzles made out of wood and iron for a tenth of the price…