A modified version of the calling card. I don't have a laser cutter, or delicate hands, but I do have a 48" x 48" CNC router! I scaled the pattern up to about 7.5" tall, modified the shape to be a square instead of a business card, and made a few small tweaks to the gears so they would cut nicely with a 1/8" endmill out of MDF.
No finish or fasteners besides glue. Just a little composite chunk of geary goodness.
Cut it out, and glue it up! Assembly is straightforward, as long as you glue the sun in first, using a small pin to line up the hole with the hole in the back, then the curved sides, aligned to the edges, and then assemble the gears, and do the top. Be sparing with the glue so it doesn't goop in and gum up your works!
I used 1/4" MDF since I had some around, but any thin ply would work. Solid wood can break gear teeth (some of the teeth will be cross-grain), so be careful if you go that route. Finished baltic birch would be very nice!
The G-CODE file is for .25" thick stock, 1/8" endmill, 1/8" passes, and 60IPM. I've attached the DXF, as well as a Vectric V-Carve file if your machine has different capabilities than mine. The gears are NOT restrained, so put adhesive tape under the stock where they will be cut out. The larger pieces have tabs programed in already.