Put a coin the machine... and see it roll down past the line of folks waiting to use the machine into a 55 gallon drum or larger full of coins. The drum spins slowly mixing the coins. A robot selects a coin randomly from the drum. And puts it in a chute that drops the coin in front of you. You can see the drum and that there are quarters, nickels, dimes, and dollars floating in a sea of pennies. Along with random coins and coin shaped tokens from may sources. Good luck.

A rather loose mechanism would reject most items not made of metal and coin shaped. A occasional pounded flat bottle cap might make through, but the crowd will see the faker and deal with it.

Mostly it is like the "have a penny leave a penny, need a penny take a penny dish". With an occasional wind fall. A place to get rid of pocket change, in exchange for a 1000 yuan coin. What's a yuan?

The casino may not make any money on such a machine, but I bet a line would form. Casinos like lines.

Added LATER: A slightly different machine with A standard vending machine rejection unit that can reject all coins/tokens worth less than a penny. You could than take the machine into counties/places where gambling is illegal, because it can not be gambling if you always at least get your money back. Make an interesting court case at the very least.
-- popbottle, Jul 25 2014

Cull coin display Cull_20coin_20display
similar in sentiment [bungston, Jul 25 2014]

Nice, you can make subtle random paybacks.
-- wjt, Jul 25 2014


Who's going to put quarters in this thing?
-- RayfordSteele, Jul 25 2014


The casino, if necessary, as a loss leader. Or all the people who have been fooled by the subtle 'How To Beat The Coin-In-Coin-Out Machine With One Weird Trick!' ads the casino has subtly been putting out. Or people who got change in quarters and have been told there is one incredibly valuable rare coin in that vat, go on, have a go, it could finance your whole vacation ... [+]
-- gisho, Jul 25 2014


Yes there could be a kruggerand rattling around in the mix.

This is really just a very much more favourable version of those coin pushing machines you get in old fashioned arcades. I used to love watching them as a wee boy. Sometimes I would nag my parents to allow me to put 2p in. That was usually enough for me to observe the leveraging ratio of the setup.
-- pocmloc, Jul 25 2014



random, halfbakery