Rockin' Timer Cup

My name is Adithya. I am 8 years old. I designed this cup with my mom for the April fool's Make: contest. After we went through many versions of badly designed cups, I decided to make a hyperboloid (sand timer shape) cup, because I like the coin tossing structure the children's hospital puts in store locations to collect coins, and I like the way the coins swirl in.

To make liquid pouring out unpredictable, I decided to add grooves to the cup. This cup has grooves on the inside of the top half so that water will flow in different directions when trying to drink and will spill on the drinker. But on one part of the cup, water will come out of the cup in a single stream because the flow grooves on the neck are blocked, except for a single groove in one small section. The drinker will have to try drinking from different locations until the water stops spilling on them, because there are no markings to show where the water will come out as a single stream.

Also, to make things worse, the bottom is slightly curved so the cup will not balance easily, and filling water might be a challenge.

Our family friend helped with designing the cup for 3D printing. He made my design for 3D printing this way:

The cup dimensions are 4" diameter and 8" tall with the top and bottom portion equal in height.

The groove with varies from the neck to the top (5 degree rotations) and there's one groove per 10 degrees. So the total grooves should be about 36.

1. One half has only one active channel. The other half has multiple channels. So, unless the person tilts in the right orientation, there will be multiple streams and thus spill water.

2. The platform hides this. So, when looked from the outside everything looks equally spaced.