[TheOsiris]

they're not, but this blog post made it seem like they're worth the money.

I don't know how I feel about this post. I don't know if I can consider it a diy project when he has access to equipment beyond the reach of most ppl. if I had access to an orthodontist lab and build my own retainer using their equipment is that considered diy?

[dezork]

The only equipment here that might be an issue for most people is the laser scanner. I'm not sure where I'd find one of those outside a university that's accurate enough. The Makerbot one is pretty shitty.

Everything else could be pretty easily sourced. Shapeways can 3d print with very good resolution. You can buy a vacuum forming machine from Ebay for 100 bucks for exactly this purpose, or make one yourself with a heat gun, wood, and a shop vac (there's tutorials on youtube).

[readme]

I don't think equipment access makes or breaks a diy project. As long as you did-it-yourself, it's diy.