Quoted from Terry1:
It seems to reject at random!
It may reject(coin) it once and then accept it!
They coins are not getting stuck. They either fall through to the return
I have yet to find a coin that is always rejected!!!
You need to take it out, and repeatedly put coins in until you have some reject, and then learn why.
The basic operation of a coin mech (mechanical, not an electronic model) is -
- The cradle catches the coin. Too large diameter, and the coin won't be cradled properly. Too small, and the coin will fall through.
- The cradle rotates, and sends the coin down a chute. This path has one of two magnets in it. Magnetic coins will get stuck here. The magnet *usually* is also a set width apart from the back wall of the channel - coins that are too thick will get stuck. Coins too thin will either fall off the path, OR, gain too much speed.
- The coin then falls on an adjustable pin. Given the speed and weight, the coin will fall into the Accept path, or to the Reject path.
Usually, if it's hit and miss, like in your case, then either-
(1) The magnet or thickness check isn't retarding the coins enough, OR
(2) The pin isn't adjusted properly, and valid coins aren't gaining enough speed to fall into the Accept side of the pin.