I designed this to be as close in shape to the classic prop from Star Trek as I could, but to be acoustic rather than electric.
EDIT: Here's an MP3 of me playing this lyre
EDIT 2: By popular demand I have added a schematic image with some dimensions. I didn't measure much of anything when I built it so i had to go measure the actual article to get these numbers.
Step 1: Basic Body
Then I printed the whole thing out. My printer isn't any bigger than yours, so I had to print it out in sections and then tape it all together. Next I cut out the whole shape, taped it to a big piece of 3/4 inch plywood and cut the sucker out. If you are a better free hand drawer than me you could probably skip most of that and just draw on the plywood. I was trying to get mine as close in shape to Spock's as possible so I was a bit anal.
Next I made a copy of it with some more plywood, then glued the halves together with some clamps.
Oh, uh, see that little area at the bottom that isn't cut out? Yeah, that's important, it does stuff. Namely it gives to something to screw the tail piece to.
Step 2: Edges
Step 3: Front and Back
Step 4: STAIN!
Step 5: Figuring Out Where to Put the Strings and Tuners.
I wanted to sorta eye ball the placement, so I made a fake bridge and tail piece out of paper, taped some strings to it and taped every thing in place. When I had the strings placed evenly I marked the neck where I wanted to drill.
Step 6: Zither Pins
Step 7: Finishing
There are fancier ways to mount a tail peice, and I'm sure someone knows them. I am a novice wood worker, so I decided to go with drywall screws. Yeah, I know, there's no drywall in this thing, but I swear these things work on everything.
The bridge is just a chunk of oak cut to form. It's held in place by the tension of the strings, so you need to get them a little tuned then sort of work the bridge underneath them.
For strings I chose acoustic guitar G strings. The geometry of the lyre can give you a pretty good tonal range, depending on what strings you choose. Heavier strings will generally give you lower notes and vice versa. I tuned mine to a major twelve note scale, you can play a lot using only major scale notes, but if you want a different scale you can always retune it.
I found that once the strings were broken in they keep a tune remarkably well. The whole thing warped a little over time but seems pretty stable. For the record, I went on to build a few more of these, and they both looked a lot better, but I sold them and forgot to get pictures. Oh well.
Oh, a note on string labeling, I had a little trouble sorting out the strings at first so I used markers to color the C strings red and the F strings blue, a system that I totally stole from Irish harps, that also works REALLY well for Vulcan Lyres. The marker rubs off after a while but I don't have to reapply very often.
I hope this has helped and or inspired you to build something cool.