The other day, here in Basel, the cashier refused to accept the cash that I gave her for lunch. And, to my surprise, with good reason. A coin that I got as change from a drink machine earlier that day was not a 2 Franc coin as it should have been, but a 25 Centavo coin from Guatemala.

The two coins are roughly the same size, thickness and weight, so a vending machine can't tell the difference.

Going by the current exchange rate, 25 Centavos will get you only 0.031 Francs if you exhcnage the currency by normal means. Comparing this to the 2 whole Francs that any Swiss vending machine will give you, this is clearly an investment worth considering.

DISCLAIMER: Don't try this at home. Or anywhere else, come to think of it.

Haha, where I used to live in Cornwall there were thousands of home made £1 coins found in vending and gambling machines.

Some people has too much time on their hands :-)

Hi Dodger,
I'll state the obvious.
Be careful how you word such "tips". As read you are suggesting that people go and fill swiss vending machines with non-swiss currency of lesser value and effectively steal from the vending company. Odds are by even suggesting it, you have committed some sort of misdemeanor.

I am sure what you wanted to do was simply point out the remarkable similarity in weight and size between the two coins and tell us to check our change carefully as you don't even think a vending machine would be able to tell the difference. That's interesting to know. Thanks.

Good point. Now noted above. You can never be too careful these days.

You're not in Guatemala now, Dr. Ropata!

I once worked in the lab for a company that made the coin acceptors. They're very sophisticated nowadays.

This company had a room full of every single coin from every country in the world, and also had common blanks and a wide variety of fake coins, it's pretty rare this sort of thing happens nowadays. All sorts of things are tested, weight and size are the obvious ones, but also conductivity and other measures. But with so many coins some occasionaly get through, and someone always finds out.

I once held back an entire new line after figuring out a clever way to jam the mechanism, but I have no tips on defeating these things.

Dodger by name.... Dodger by nature ;-)

Well, that is one reason why I've had this name for many years...

would that have been mars? I used to own a games machine company in the uk, and spent many hours re-programming coin mechs everytime a new coin came out or was retired. re the fake £1 coins, they where easy for the mechs to spot, they where usually lead for a start, never had one fool any of our mechs, we did used to get some french francs get through but the dumb **** who stuck em in the machines didn't release they where worth more then the coin they where copying, so that didn't bother me at all

I also find the size of .50 rappen and Australian .05c eerily similar.

'twas indeed.