Also, you do need to obtain accession numbers for DIY projectors, since the CDRH views the act of using the projector to do paid shows as "entering it into commerce". In my experience so far, however, it's not hard to get accession numbers for DIY projectors as long as the 5 key requirements are met:
1) Correct labeling on the projector housing and at the aperture, detailing the hazard level present. Basically a standard "laser warning" label will work, but it needs to include wavelengths and total max power output. There should also be a warning to avoid exposure.
2) A case interlock that kills power to all laser systems when the case is open (unless bypassed by a qualified operator for maintenance).
3) A keylock switch to prevent activation of the laser unless the key is present.
4) A shutter or instant kill switch to prevent output in the event of an emergency or other safety system failure.
5) A front panel emission indicator light, consisting of an LED or other lamp on the front of the projector near the aperture. This serves as a warning that laser emission is occurring or about to occur.
So far in my experience these requirements are all you need to cover. Other than that your projector could be made of jello and whipped cream. For the longest time I was convinced that a person needed to buy "pre-varianced" cases, parts etc, but that, it turns out, is a total crock. Using projector cases that already incorporate the necessary features and have been granted accession numbers is HUGELY convenient, but if a person is patient and thorough in ensuring the requirements are met, and descriptive when submitting their product report then ANY projector design can be granted an accession number. Hence X-Laser.
Here's a few more good resources:
U.S. regulations - Laser Compliance®
http://www.fda.gov/downloads/medica...onandguidance/guidancedocuments/ucm095304.pdf
Procedures for Renewal and Amendment of Certain Laser Light Show Variances (Laser Notice 55)