If you have young children that aren't too careful with open cups, or if you'd just rather not have to worry about accidentally elbowing your drink, then this convenient little holder would help you out a lot. It keeps your cup from tipping over easily, AND acts as a coaster to protects your tables and counters.

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!

No-Wobble Cup Coaster.stl
Download View in 3D

Step 1: The Base

To make 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

To make 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

Step 3: The Outer Wall

To create the outer wall:

1) Make a circle with a diameter of 9 cm
2) Extrude the circle up 5 cm
3) Taper the cylinder out 21.81°
4) Move the shape and delete the circle from underneath it
5) 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

Step 4: Assembly

Assemble:

1) Snap the outer wall to the base by selecting the top-most face of the outer cylinder and the top face of the base, and pressing enter/return
2) Move the inner wall up 3.5 cm, and align it inside the new ring of the outer wall, as accurately as you can
* It helps to switch the viewing angle in the upper right corner. It helps a lot.

Step 5: The Ring

The ring:

1) Make a circle with a diameter of 9 cm
2) Extrude the circle up 4.1 cm
3) 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 1 cm
4) Extrude the cylinder down -4 cm
5) Snap the this new flat ring to the top of the inner wall, by selecting the under side of the ring and the top face of the inner wall and pressing enter
6) Use the combine tool to combine these two figures that you just snapped
7) Move this newly combined object up so you can see the underside of the flat ring
8) Snap the underside of the flat ring to the top face of the outer wall
9) Combine all of the figures into one figure

Step 6: Make It Pretty

Make it pretty:

1) Now that this is one object, select it then select the "Material" button
2) Make the object rubber (it's anti slip, so your drink won't slide either)
3) Choose a color you want, and check off "apply overlay"
* sorry for the mess up in the screenshot, just ignore that
4)Use the fillet tool under "Modify" to smooth the edges

Step 7: Done!

You're done! The cone-like design of this holder is the support against any surface, that keeps your drink from wobbling. However, the inner wall plays a huge role in making sure your drink can't tip around too, by accounting for the middle section of your drink..

Thanks for reading! If you enjoyed this, then a vote in the 123d Design Contest would be great, thanks! :) By the way, this is to scale and all attached so it is 3D printable!

If you want to make a different size, then I've included a formula for doing so (It'll require a graphing calculator)

Comment if you have any questions, thanks