This Instructable is going to show you how to make a 3D printable drink holder on 123d Design ( http://www.123dapp.com/design ) that drastically decreases the chances of your drink tipping over, acts as a coaster, and can be washed.
Now, the attached is an stl. file of the holder I made (No, the poorly made soda can isn't included). It will fit drinks with a diameter of 7 cm or less (most soda or beer cans, bottles, and cups). You can download mine, or If you want to make a larger or smaller holder, I'll leave a formula at the end of this Instructable so you can plug in your own measurement, get the angles right, and have a holder that's to scale when printed!
First thing is first, download the desktop version of 123d Design at http://www.123dapp.com/design, open a new project, and change your unit to cm if it isn't already!
Step 1: The Base
1) Create a circle with a diameter of 13 cm
2) Extrude the circle up 0.5 cm
3) Move the shape and delete the original circle from underneath it
Step 2: The Inner Wall
1) Make a circle with a diameter of 8 cm
2) Extrude the circle up 3 cm
3) Move the shape and delete the circle from underneath it
4) Use the shell tool to select both faces (top and bottom) of the cylinder you're working with, and make it hollow with a thickness of 0.5 cm