This is a remix of a collapsible cup found on thingiverse. This design is based on a collapsible cup I had while growing up. It was an off-green color, didn't work very well at holding water, but I used it all the time. Water fountains at school, camping, you name it. Put snacks in it for your kids, or treats for your dog.

Just as my original one had, this one has a simple case (the bottom portion is permanently attached and serves as a drip tray), and the top part can be removed and can also be used to collapse the cup back down into its flat form.

There are also a series of grooves on the outsides of each inner ring and a series of raised rings that, as the cup rings are extended, the raised portions should seat in the grooves and create a sort-of seal. I say “sort-of” because the first time I printed this after finalizing the design, I dispensed it and was able to fill it to the top with water and it held for over a minute. After dumping the water and dispensing a second, third, fourth time, it began to leak more each time. Not sure why this is so further testing is needed.