Designing the shape of the body was an interesting exercise. For the first pass I simply raided my kids' lego sets (a good collection to start with) and built it out on the back of my Les Paul. The shape was close enough that I convinced myself something reasonable would be doable. I only built it one layer thick, and it was littered with very strange pieces. I also only used basic 45 degree sloped blocks for the sides.

The next thing I did was find out the size of the slot for bolt on necks and built the top of the guitar at full thickness (6 "pips"). This was a proof-of-concept step for me to see if I still thought it was a good idea. I think Leo Fender was a Legomaniac: it turns out a channel 7 pips wide, 8 blocks tall and 2 pips deep is within 1/16th of an inch of the right dimensions for a standard Fender bolt-on neck. Go figure.

To add to the geekness of the design process, I wanted to use my computer to help layout the curves. I went to a number of Lego fan sites and downloaded some of the programs for designing with Lego, but they all turned out to be too cumbersome for building something of this size. I ended up using the obvious tool: Excel(!). Excel actually has an okay drawing program within it, and I was able to build all the blocks to scale and play around with 2D layouts. I then shot a picture of my guitar with Lego on it for scale and layered it in so I could use the shape as a template. Here's a screenshot of the layout sheet: (Note the extra pieces strewn over the carpet - just like real life!)

Once I had the shape defined I filled it in. This screenshot shows the "Lego grid" with places for the pickups, bridge and electronics. The blue blocks represent the channel inside the body for the wiring to travel through. The vertical pieces are side views to layout the edges so I know how many of each type of sloping block I need to get.

When I built v2 of the body I followed the design from the overlay picture (I hadn't made the grid image yet). It took most of two blue buckets of blocks (1200 pieces each, about $20 at Toys 'R Us). I goofed up and missed the fifth layer buidling from the bottom, so the body ended up being one block thinner on each side. As it turned out, this was much truer to the real guitar, so I corrected that in the grid version. Let's hear it for small mistakes. Here's what it looks like.