Notwithstanding that the Glowforge is described as a ‘3D Laser Printer’, details of a cheap way to convert your 3D Printer to a Laser Printer. Depending on the laser module, only talking about 0.5W or 2.1W but might be fun. Just be careful of any open casings and that laser…
Given the current date (and hopefully the imminent deliveries), may only be useful for those who have to wait until March 2017 to receive their Glowforge…
Hmmmmm…not so sure about that one. We had a discussion on the safety aspects of doing something like that over on the MakerGear forum and came to a consensus that it wasn’t the greatest of ideas.
(I think I recall one fellow saying he was going to do it anyway, but he hasn’t come back to tell us if it worked or not.)
It’s not very wise, and until you get to the higher-wattage modules it doesn’t really do much. (I have a bunch of pieces of paper and thin pieces of wood with very thin black lines and occasional holes in them from my lasermouse project, but mounting a technical pen would do most of the same things. (And yes, you really need the glasses, and even if you have the glasses you will always be wondering if you just damaged your eyes. Unless you have opaque/absorbent sidewalls.)
Pretty much with all laser cutters/etchers, regardless of wavelength, if you are going to stare at that little spot where the material is being vaporized, you need broadband protection…i.e. sunglasses. That’s why most lasers are enclosed with the laser head very close. If you make an open laser like this instructable, with upgraded power, don’t stare at the spot where it is cutting/etching unless you have wrap-around sunglasses or a welding hood 
- Rich
Maybe he’s trying to figure out why everything is so dark?
Yup! 
Beat me to it… 
And that little spot is so %^#%$& hypnotic. (Did anyone else try to see how long they could stare at the sun when they were kids?)
The laser spot is many times less dangerous than looking at say, a welding spot. The welder can actually get a sunburn on unprotected skin. But your eyes are much more sensitive than skin. I think some of the doctors on this forum can give you some of the effects better than me. Laser safety goggle that protect a narrow wavelength, won’t protect you from the broadband light coming from that plasma spot. - Rich
Note that the Glowforge lid has been designed and tested to absorb both UV and IR, so it is quite safe (and indeed, hypnotic) to stare at the glowey white part.
For any other device, your mileage (and eyeballs) may vary.
- Rich