Coffee Cup Doubler

Like many of you I have in my cupboard 12 items of everything, including 12 coffee cups and coffe cup plates.

I may need all of them when I invite people in, but most days I only need 4 cups or so. Still the 12 cups take up space, so I came up with this simple solution : store 12 cups within a footprint of only 6, hence the name Coffee Cup Doubler :-) 

This shape of the Coffee Cup Doubler is such that it stays nice on top of the bottom row of cups and the top row of cups won't slide off either : there is a border on either sides for that purpose.

This project doensn't require much materials or tools, but you will need to work with high precision : the final piece is only few millimeters thick, so your routing will need to be accurate.  This instructible is also a lesson in routing : how to make the best use of this versatile tool.  As always, patience and practice make perfection.

Enjoy !

Step 1: Materials & Tools

Materials :

* Piece of wood : 30 x 16 cm (12" x 6"), thickness ~10 mm (3/8")
I decided to make this from some leftover Oak* : the resulting piece will be quite thin (4 mm - 1/8") so solid wood is needed for strength.

Tools :

Caliper, for accurate measurements down to a millimeter.
Router, with a straightforward routing bit. I used my 12mm, I guess in the US that would be 1/2"
Sander, I used my orbital sander
Clamps, to keep the piece fixed while routing


Other :
Wood oil, I used Skydd from Ikea

* : I actually glued some boards together, but this is not essential, It's actually easier to use one solid piece of wood.

Step 2: SketchUp Model

In order to visualize things, I've made a SketchUp model.
This way you can easily adjust any dimensions and experiment with the object, before actually starting to cut wood.

Step 3: Routing

We will start with a nice rectangular piece, and then remove 2.5 mm (1/16") from both surfaces. This way we will end up with a piece of ~5 mm thick, and with a border on both sides. The border is ~ 2mm high and wide..

The exact dimensions may need to be adjusted according to your raw materials and your size of cups !

You will need some guides in order to keep a nice 2 mm at each side.


Furthermore you will need guides to keep the 2.5 mm depth, consistently over the whole surface.
If the base of your router is large enough, it will rest on the sides of the workpiece at any position, but most likely it won't be like that : in that case you need to extend the routers base plate by mounting a scrap piece of wood under it. Ideally it extends your routers base plate to the sides, and not to fore and after sides, so you can use the wide baseplate to control the depth of routing at all times, and use the front and guides to control the minimum distance from the sides.

Take a scrap piece of wood, power the router on and run a test on all guides : check depth and width of the border.
when you are confident that your setup has everything under control, go for the real piece.

Step 4: Finishing

Finish by sanding : as the piece is quite fragile, be carefull not to destroy it by pushing the sander onto it too hard. You could use a scrap piece of wood under the piece, so it rests on this, and not on the side-borders only.

Then apply wood-oil. Let it dry and you're done !

Did you like it (the result and the routing lessons you've learned) send me a picture !

Happy Woodworking and Coffee-breaks :-)