Fixing a Cotton Candy Vending Machine

Cotton candy is probably the best way to eat pure sugar, which makes having your very own cotton candy vending machine to automate making it a bit of a dream. The machine that [Block’s Retro Repairs] got should therefore make him very happy, but unfortunately it was bought as defective. After digging into the machine in an earlier video, this time around there’s some actual success and proper cotton candy to enjoy.

The way that cotton candy is made involves spinning thin threads of sugar, which are created by the heating and rapid crystallization of the sweet stuff. Unfortunately this machine wasn’t even really extruding sugar any more, so it had to get a deep clean to remove probably years of crusty buildup. After this things still weren’t working right, although cranking up the temperature on the induction heated head improved the results somewhat.

To really fix the machine, this head with its clearly dodgy thermocouple had to be disassembled. This revealed that said sensor was looking rather frayed, potentially shorting out against the aluminium head and likely not in the entirely right position any more. After adding some insulation back and making sure that the thermocouple was located closer to the top of the head, it was time for more testing.

Repairing the thermocouple seems to have fixed most ills, with still some calibration of the temperature required, but finally resulting in fancy shaped cotton candy in its myriad of colors. Along with the looming hazard of potentially acquiring Type II diabetes from all the testing, there was still a problem involving the remote management feature of this Red Rabbit machine.

These $6,000 vending machines do feature an Android 7-based software with a Rockchip SoC and access to a lot of settings via its large touch screen, but features such as setting prices for the products are locked away via a remote account. The machine was sadly still linked to someone else’s account, and so far Red Rabbit support had not responded to any documentation, repair help or account unlinking requests. This has left the machine in somewhat of a pickle.

It was possible to dump the software of the machine, which can be fetched from Archive.org, so if anyone would like to pitch in and break this remote lock, that would be very welcome. It’s also considered to replace the cash reader with a simple button or so, but where’s the fun in that?