The project has been coordinated from Geekhack (thread here), and the group buy run through reddit. The Geekhack link has reddit threads and related discussion.
Files are posted, Video below of me explaning how to put it together.
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9mm (~3/8") for High Profile
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6mm (~1/4") for Upper and Lower Middles
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3mm (1/8") for Bottom
Either a 1/4"-20 (Imperial) or M6 (Metric) tap will work. Holes are compatible with either. My preferred cheap source is Shars. Links for: 1/4-20 and M6 The easiest and fastest way I've found to tap is to chuck the tap in a handdrill. Run the tap forward into the hole (after it's been poked clean of acrylic) until the taper clears. Usually, you can tell because the drill will run easier after it has completed the thread. Release the trigger and let the drill stop, then reverse out. The important thing to remember when tapping is ** keep the tap perpendicular the workpiece! ** I've found keeping in the acrylic stock helps to prevent the middles from snapping or bending too much.
It's similar, but a bit trickier because the holes are a lot smaller. An M2 tap like this one is what you'll need. Make sure the hole is clear, and follow the same proceedure as above. Be careful, as the flute lenght is only a little longer than the acrylic in most cases. Also of note is how for laser cuttering, it's important to get the hole very close to the needed dimension. In my earlier testing, telling a laser to cut the right .063" (1.6mm) without cutter compensation made the hole too large for the screw to bite in after tapping. What I did afterward was undersized the holes in CAD to .055" which worked most of the time. In some cases, there was still some issues with slippage. In that case, a little glue in the hole right before you stick the screw in can help.
I've attached my "Assembly Counting" sheets, which are a packing list or the full acrylic or double plate case hardware packs. In the group buy, these came in little ziplok baggies. The lists include the McMaster Carr part numbers for what I used. If you want to make your own, they are probably your best source. The one exception are the metric tenting screws, which I got from Allen Fasteners.
Each tenting screw has been plastidipped for skid prevention. The process is pretty simple, buy the can, dip the screw up until about the square part of neck, and have it dry vertically. I used the side flaps of a box with a 1/4" hole drilled in them to support the screws. One coat was plenty thick in my experience.