I've done this twice now, and to make a proper one you may need to as well. I'll explain why in a minute, but if you'd like to try your hand you'll need:
- Wood (I've made little ones out of packing styrofoam and a pocket knife as well, though)
- A bandsaw
- Acrylic paint/sealer (optional)
- A drill press
- A coping saw
Step 1: Cut a Cube
Step 2: Imagine All the Letters...
This step is actually the most important, but also probably the most difficult. All you need to do is draw your initials on each side of the cube, and imagine what shape will result when you cut them out. Some initials will cause problems in certain configurations. I've drawn a shoddy diagram in mspaint to try to help you visualize this.
Imagine that, like me, your first initial is a 'G'. You'll need one profile to have that shape, so you'll begin with a block letter 'G' that's as thick as your cube. Your final product must be contained within this form, or else your profile won't look like a 'G'! In order to form the other letters, you just need to remove material. You can remove as much as you want, as long as there is some wood at all points along the 'G' shape.
In the diagram, I've shown two possible ways to create an 'I' profile from the front of the cube. The blue parts are the parts that need to be removed in order to form the 'I' in each case. On the left you can see that the shape is too narrow, and there will be no wood to create the 'G' on the sides. Even worse, the cube is now in three separate parts! On the right, you can see a successful design. The caps on the top and bottom of the 'I' provide enough material to keep all parts of the 'G' in place. Note however that the top and bottom of the resulting design are now only held together at those three places where the middle of the 'I' hits the 'G'.
Basically, what you'll need to do is ensure that each letter spans the full face of the cube from top to bottom and left to right. As long as there is some material at every point along these axes, the other shapes should be possible to produce. A more complex consideration is structural stability, as I mentioned above. The first time I tried this in wood, my initials came together in such a way that only a very thin piece of wood was left connecting two relatively massive parts of the design. This bit snapped in short order, and I had to glue it back together. You can see the bit of tape in the photo holding it together. The second time around, I rearranged the letters so that this would not occur and the result was much stronger.
Step 3: Cut Them Out!
After this shape is cut out, take stock of your letters again. You may have cut off some of the surfaces you had drawn on, so re-draw those bits of your template. Pick a second letter, and simply cut it out again while ignoring the first shape. Same for the third.
Step 4: Touch Up, Sand
Step 5: Add Color
The first stage is to paint all of the visible parts that make up each letter's profile. You'll have some edges left over after that which are not visible from any side (for example, all of the backs of the letters). These you can paint as you wish, I tried to continue the colors along perpendicular edges so that each letter kept its proper color from as many slight angles as possible. You can see this in the first picture, where part of the back of the 'G' is painted blue to keep the 'R' looking blue even if the cube is slightly rotated .
Step 6: Enjoy! (More Pictures)
As always, I'd love to see photos of your block! And by the way, for those wondering... my middle name is Jean. I'm half-Swiss =P