Vending machine wtf



  • This morning, arrived at the office, visited a vending machine for some drink. The one I wanted costs 230 HUF and I had only 200 HUF coins so I inserted 2 of them. Pressing the button next to the one I wanted, the display blinks: SOLD OUT... Good monday morning. Ok, let's get the money back, I pressed the "return money" button. Coins begin to fall 50 + 50 + 20 + 20... and nothing more....
    It just doesn't add up at all. I can't imagine how it miscalculates the amount it needed to return because there are not enough numbers in the game that could add up to 400.


  • Discourse touched me in a no-no place

    The only vending machine I quite like using on a regular basis sells railway tickets and only accepts chip-n-pin cards. No chance of overcharging…


  • Discourse touched me in a no-no place

    One of ours returns the change after every selection, which is irritating if you've put a larger coin in for multiple things.
    Worse is when it returns change which it then won't accept back.



  • I've had vending machines return your money in change but always, I think, to the right amount. That's annoying enough... In goes a 2 pound* coin, out comes four 50p pieces.


    Filed under: *The monetary unit, not the weight; Coincidentally four old 50p pieces weighed two pounds.



  • Once when late for a train, no time to get anything smaller, I had to buy a 13 euro (or thereabouts) ticket with a fifty euro note.

    Cue 37 clinks as 37 single euro coins poured out of the machine...



  • Not long after Melbourne's Crown Casino first opened, I visited it to see what all the fuss was about.

    Inside this huge windowless climate controlled carpeted piped muzak space, carefully constructed so as to disconnect the occupants from anything that might remind them of the passing of time, are row upon row upon row of bleeping flashing poker machines. And in front of almost every one there sat a dead eyed loser feeding in coin after coin after coin.

    Every now and then, somewhere on the gaming floor a machine would make a joyous electric noise and disgorge a handful of dollar coins into its payout tray. I saw this happen twice. And both times, the player didn't even crack a smile. They just picked up all the coins and started feeding them straight back into the machine.

    Righto, I thought. I've worked for a mob that makes these hellish engines. I know how they're programmed and I know about their little payout percentage thumbwheel. But I'm buggered if I'm going to go to the trouble of pedalling my bike all the way here without getting into the spirit of the thing.

    So I found this rather small machine stuck on a pillar in the middle of the space. It was plain white and not at all flashy, and it didn't have a screen, but it did have a slot at the top and a payout tray at the bottom. So I fed a $2 coin into the top slot, pressed the button, and was instantly gratified with a rattle of dollar coins into the tray.

    When in Rome... I took that pair of dollar coins and fed them straight back into the slot. And two more rattled straight back out.

    Ripper, I says to myself, I can't lose here. So I fished around in my pocket and fed all my loose coins into the slot. And with a rattle and a clank, Crown Casino's change machine took my $3.85 and gave me back three shiny dollar coins.

    The house always wins.



  • I suspect it didn't miscalculate, it just ran out of change. Often on that type of machine there's an input holding area for money completely separate from the coin return, so you putting things in doesn't mean the machine has more change.

    It's either a dumb idea or a brilliant one depending on which side of the fence you're on.



  • One time at college, a vending machine was broken and returned more change than was due.

    We cleaned it out.

    I feel kind of bad thinking back on it now.

    Cool story, bro.


  • Discourse touched me in a no-no place

    The building in which I work has a vending machine. The guy who owns it--it's not owned by the building, nor by the management--is dilatory about stocking it. It has--had, actually, more about which anon--this obnoxious failure mode where it'll take 2 quarters--but no more--for a 75¢ drink. You want your Coke, you better have some other change or a bill.

    The animals in another office have managed to fix that problem by jamming the coin feed slot--I noticed last week that if I had a knife or some tweezers I probably could have gotten a couple of dollars in quarters out of the top of it--and then breaking the coin return. Since then someone has helpfully put up a "bills only" note.


  • Grade A Premium Asshole

    @KillaCoder said:

    Once when late for a train, no time to get anything smaller, I had to buy a 13 euro (or thereabouts) ticket with a fifty euro note.

    Cue 37 clinks as 37 single euro coins poured out of the machine...

    I had something remarkably similar happen to me. I had a couple of meetings downtown and I had no small bills. After the first meeting (which had a very expensive parking garage) I went to the payment machine (pay before you get in your car) and I knew I would need some 1's for the next parking area. My parking came up to $10.50, so I thought I would be smart and feed in a twenty and get some small bills in change. As soon as I put in the $20 bill the display flashed "out of bills" and proceeded to spit out 38 quarters.

    For bonus points, the elevator was on the fritz so I had to hook it up 5 floors of stairs, jingling all the way.

    For more bonus points, I felt like an asshole making people wait so I could pay for my parking at the next meeting with a fuckload of quarters.



  • We encountered a few of those belt-operated Coke vending machines. If you blocked the exit port it would assume it failed and returned your change, but left your purchase on the belt. Then you could use your returned change and buy another, and both of them would pop out the next time. If you were good, you could get 3 - 4 for the price of one.

    We didn't see those around for much more than a year. Everyone figured it out and they got upgraded.


  • Grade A Premium Asshole

    I once ran across a vending machine with a strange error that I assume was caused by the augers being off index in one slot. I have no idea how to explain it, but I bought a Snickers bar and the auger advanced but not enough for the candy bar to fall, so it advanced again and the Snickers fell immediately but nothing fell as the auger stopped, so it advanced again, and again, and again...until it fed all of the merchandise from that slot.

    I believe (and this is pure speculation) that because the auger was off index the impact of the candy bar on the bottom of the slot did not coincide with the part of the programming that listened for the event so it assumed a feed error and fed again. Lather, rinse, repeat.


  • Discourse touched me in a no-no place

    @mott555 said:

    belt-operated Coke vending machines.

    Yup. There were a bunch of high-schoolers putting up youtube videos showing how to abuse them.

    I tried it once, just far enough to demonstrate proof of concept, by which I mean that I let it jam up, then uncovered the door so it would drop my coke and not try for the free one.



  • @blakeyrat said:

    One time at college, a vending machine was broken and returned more change than was due.

    I remember one time when a vending machine ran out of cups at my uni, and the return button didn't work. I've watched a few people miss the big "NO CUPS" sign, put their change in, bash the return button and take off pissed.

    When the counter was at about 10 or so coffees, I went to another machine, took a cup of water, drank it, set the empty cup under the nozzle, bought myself a coffee and took the loose change.



  • I put myself through university (well, a month of it) on a machine that read $2 bills (this was in Canada) as fives.



  • My vending machine story is the one at my high school was a little worn out. If you put the coin in and pressed multiple buttons out could come multiple cans. You had to be lucky but the record I saw was 5 cans for the price of one. From memory sprite was the most reliable to get free ones.


  • :belt_onion:

    @Zemm said:

    My vending machine story is the one at my high school was a little worn out. If you put the coin in and pressed multiple buttons out could come multiple cans. You had to be lucky but the record I saw was 5 cans for the price of one. From memory sprite was the most reliable to get free ones.

    I have been in 2 places that had that problem. Race Condition Coke Machines... and sometimes there's ties!

    In High School (apparently everyone's highschool had busted machines?) we had a machine that started giving out multiple sodas per payment in this scenario, and after abusing it a couple of times, it decided to just give up and empty its entire contents. We had to go get a cooler to stick all the sodas into.


  • Discourse touched me in a no-no place

    When I was in college, someone discovered that acid in the bill collector would destroy the sensor it used to determine whether or not real money was being inserted. The college replaced the machine in one dorm where people kept doing this a surprising number of times before finally telling them the could just go without.



  • In Microbiology we had to sample various surfaces or items for Petri dishes and see what we could get to grow. We sampled toilet seats, keyboards, floors, doorknobs, even the Big Blue Mint at the bottom of the urinal. Yet the clear winner was the Mountain Dew button on the main lobby's vending machine.



  • Apparently, here in the Netherlands, there used to be a vulnerability in the ATMs that allowed you to get free cash. This was before my time so it would have been in the seventies or before that. The way it worked was you asked for 300 guilders (the Dutch currency before the euro), which was the maximum you could get and you'd get three 100 guilder bills. You'd take out the middle one, and leave the other two: the machine would assume you had not taken any cash and bam, free money. A guilder was worth about half a United States dollar. I'm told that students caught on and exploited the flaw and they fixed the ATMs after that.

    Of course this may well be an urban legend.


  • Discourse touched me in a no-no place

    A little update on the vending machine where I work. Now that it only takes bills, it has run out of change, so you can't buy anything.


  • Grade A Premium Asshole

    @FrostCat said:

    When I was in college, someone discovered that acid in the bill collector would destroy the sensor it used to determine whether or not real money was being inserted. The college replaced the machine in one dorm where people kept doing this a surprising number of times before finally telling them the could just go without.

    Back in the day (early 1990's?), you could fool them with good photocopies. I...uhmmmm...a friend of mine paid for more than one car wash as a broke high school kid using this method. I would never do such a thing though. I am a model citizen. ;)


  • Discourse touched me in a no-no place

    @Intercourse said:

    Back in the day (early 1990's?), you could fool them with good photocopies.

    I wouldn't be surprised if you still could. Except supposedly modern printers will freeze up or something if you try, and I don't have access to a throwaway printer or really the desire to cheat someone, except possibly the guy who runs that shitty vending machine where I work.


  • Grade A Premium Asshole

    @FrostCat said:

    Except supposedly modern printers will freeze up or something if you try

    Not true. I heard the same rumor and tried it a few times. Nothing happened.

    Also, the sad thing was that back in the day my friend told me that you only needed to copy the front of the bill. My friend told me that the back of the bill mattered fuckall.


  • Discourse touched me in a no-no place

    @Intercourse said:

    Not true. I heard the same rumor and tried it a few times. Nothing happened.
    Well, like I said, I never had access to a printer I wanted to take the chance of getting ruined.@Intercourse said:
    Also, the sad thing was that back in the day my friend told me that you only needed to copy the front of the bill. My friend told me that the back of the bill mattered fuckall.

    That was actually true.


  • Grade A Premium Asshole

    @FrostCat said:

    Well, like I said, I never had access to a printer I wanted to take the chance of getting ruined.

    Which is why you roll with it when the idea pops in your head while in the office of some fuckwad you don't particularly like.

    @FrostCat said:

    That was actually true.

    Maybe I should have denoted the sarcasm in that one? 😄



  • We have a vending machine that must have been made when D-flipflops were first invented and people started using state machine diagrams.

    State 1:
    Message state
    (User presses combination, go to state 2)
    (User gives money, go to state 3)

    State 2:
    Display money amount
    Go to state 4

    State 4:
    Spend 30 seconds here in case people have dyslexia reading
    Ignore all user input
    Go to State 1

    State 3:
    Take money
    (If money scan bad, go to state 5)
    (If money good, go to state 6)

    State 5:
    Spit out money
    Go to state 4

    State 6:
    If user has wasted 30 seconds fighting the machine, go to state 5
    If user has picked their item correctly, go to state 7

    State 7:
    Spit out food
    (Go to state 4)



  • No, they won't do that.

    What they will do is mark the paper with tiny invisible yellow dots, so if you do use a color copier/printer to counterfeit bills, the Secret Service can trace the bills to your specific printer. It doesn't prevent it from happening, but it gives them rock-solid evidence for a conviction.



  • I thought there was a thing where Photoshop refused to work if it detected US currency...



  • I know that there is a thing where photoshop refuses to let you scan euros. I know because I remember reading an article where Adobe confirmed it to the journalist but said they couldn't really say more than that. I could be mistaken about the currency so it might be dollars instead of euros.



  • How can Photoshop prevent you from scanning anything? Probably can prevent you from editing it, though...



  • I think they sort of refuse to import the scanned image or something. Like you can scan it but Photoshop just says no, it doesn't allow the picture "into" the program.



  • Both dollars and euros. And a large number of other currencies. My color printer stops in the middle of the print (does not self-destruct) and all the color copiers at work refuse to copy them with a (rather cryptic) error message about something being forbidden.

    As far as I know, it's all based on this: http://en.wikipedia.org/wiki/EURion_constellation

    I've never seen a black-and-white machine (printer or copier) implement this restriction.


  • 🚽 Regular

    My only issue with a vending machine was when one dispensed coffee, followed by sugar, followed by the cup which was supposed to hold it. Not a terribly interesting anecdote.
    @Planar said:

    As far as I know, it's all based on this: http://en.wikipedia.org/wiki/EURion_constellation
    I felt tempted to look for this pattern in your avatar after reading that.



  • @flabdablet said:

    And in front of almost every one there sat a dead eyed loser feeding in coin after coin after coin.

    Some 20 years ago I was in Kopenhagen and saw much the same in the Tivoli amusement park in the city center — except the dead-eyed losers tended to all be pensioners, and there was not even the attraction of money to be won since the slot machines only worked with special coins sold to visitors for the purpose of putting into those slot machines …


  • Discourse touched me in a no-no place

    Our tea & coffee machine, which gives paper cups, once gave me a yellow cup with "SAFETY CUP" written on it. I wouldn't have cared if it wasn't for the lid not fitting on the "safety" cup.



  • @toon said:

    Of course this may well be an urban legend.

    I don’t think it is — I seem to recall seeing an item about this on some TV news or current events programme way back when. The reason it worked was because ATMs at the time only counted money as they took it from storage, but not when they put it back if the customer didn’t remove it from the machine; the fix (obviously) was to make the machine count it both times and charge the customer with the difference.



  • I just scanned the paper money I found in my wallet:

    The above is reduced in size — I scanned it at 300 DPI, but reduced the scan to 500 pixels wide to post here, as I thought 2493 pixels would be excessive. I saved the original as a PNG and tried opening it in Photoshop:

    It will happily open the 500-pixel-wide version, though:



  • @blakeyrat said:

    What they will do is mark the paper with tiny invisible yellow dots

    At risk of being a pedantic dickweed, how can an invisible dot be yellow?

    I've successfully scanned an printed AUD50 note (to make a pretend gift voucher for someone). But for a long time Australian "paper" currency has been polymer rather than paper, so not much chance of any home-printed jobs being confused with the real thing.


  • 🚽 Regular

    @Paddles said:

    At risk of being a pedantic dickweed, how can an invisible dot be yellow?
    By being so small people don't see it?

    By being such a slightly different yellow than its surroundings than a person can't distinguish it but a machine can?



  • @Paddles said:

    At risk of being a pedantic dickweed, how can an invisible dot be yellow?

    See here.


  • Discourse touched me in a no-no place

    While yellow dots are _visible_, they are **very hard to see**.

  • I survived the hour long Uno hand

    @mott555 said:

    In Microbiology we had to sample various surfaces or items for Petri dishes

    We did that in high school. We all expected the sample from the lunch meat someone had stuck to a window that didn't get cleaned off for weeks to do as well as the toilet sample, but they were both underwhelming.



  • @Paddles said:

    At risk of being a pedantic dickweed, how can an invisible dot be yellow?

    Because it's a fucking 300-3000 DPI printer, and it's just one dot, and it's yellow-against-white. Unless you're fucking Superman, that counts as invisible.


  • Discourse touched me in a no-no place

    @blakeyrat said:

    What they will do is mark the paper with tiny invisible yellow dots, so if you do use a color copier/printer to counterfeit bills, the Secret Service can trace the bills to your specific printer. It doesn't prevent it from happening, but it gives them rock-solid evidence for a conviction.

    I've heard about that, too. Gonna be hard to trace a printer that was paid for in cash. Or, for that matter, finding the yellow dots on a monochrome printer, assuming you could find a scanner willing to take black money instead of green.


  • Grade A Premium Asshole

    I did some Googling about it and there is anecdotal evidence of people who when trying to scan a bank note had their AIO print out a page saying that it would not do so with a URL for a website about the penalties of forging currency. I believe it was Canon and HP printers?

    (I wonder how many NSA filters we have tripped on this board, BTW)


  • :belt_onion:

    @Intercourse said:

    (I wonder how many NSA filters we have tripped on this board, BTW)

    As long as no one mentions ISIS, we're ok.


  • :belt_onion:

    @darkmatter said:

    As long as no one mentions ISIS, we're ok.

    Oh shiz. And with google's love of TDWTF, we may become the top link for ISIS searches by the end of the day.



  • And I just wanted a drink... now you are printing banknotes. I won't ever dare to open a new topic.:)


  • Grade A Premium Asshole

    @balazs is a sheepophile?

    How is that for a change in the conversation that will forever be on Google?


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