Here it is. Version 3.0 of the PublicLaboratory.org mobile spectrometer. This spectrometer is a scientific tool that straps onto an Android or iOS phone, tablet, or any camera capable of focusing very close (macro-mode) and allows you to collect spectra. Why would you want one? You can use it to identify the elemental composition of things (light bulbs, olive oil, beer, etc) based on the colors of light they emit. You can even use it to monitor your home brewing progress (http://bit.ly/Xyor6B).
Version 4.0 will be released very soon and is a much more refined design. You can read more about it here: http://publiclaboratory.org/notes/braddudenhoffer/2-11-2013/evolution-plots-smartphone-spectrometer-0
Assembly is much easier than earlier models.
Print the two parts (the base and the body either plain or with the logo)
Attach a film grating to the upper side of the base
Secure the base to the body with hot glue, tape, or if you print with ABS by solvent welding it together with acetone.
Mount it to your phone
Use spectralworkbench.org to calibrate, save, and share your spectra. There is a native iOS app in the works but I can’t say for sure when it will be released.
If you use an extrusion printer such as a Mendel you will probably need to print with support if you want the text to show up. If anybody wants a version without the text, let me know and I will post it ASAP. Also, make sure you have your printer tuned up to print bridges and overhangs very well, because this thing is basically one huge overhang. I have successfully printed it on a MendelMax. The walls are little thinner than is ideal but that will be fixed in the next version :).
All parts have been NetFabbed and verified.
This is the grating I have used for the prototype. It is the linear style with 1000lines per mm: tinyurl.com/9tjrz8r . You can also use the film off of a CD, DVD, or BluRay as seen here: http://publiclaboratory.org/tool/spectrometer
License: CERN OHL v1.1 Public Lab contributors