Silhouette Cut Public Lab Mobile Spectrometer

I am a fan of spectrometers. These instruments are used in industry and science to find out about compositions and of things(liquids, stars, leds, compact fluorescent tubes) through the light they emit or absorb. Typically, they are expensive (1000's of $£) because of their precision, but there also affordable useful versions for use in DIY Biology or citizen science.

Public lab has developed a series of these spectrometers, as well as software that can be used in browser.

The one I am interested in is the cheapest one, the Foldable Mini-Spectrometer. You can Build your own with a printer, scissors, some card, tape/glue and a blank dvd. I used the "Build your own" page as a reference, and if there s any directions you find unclear, they probably said it better.

I am especially grateful that they release all their stuff under a Creative Commons Attribution-ShareAlike 3.0 Unported License with Hardware designs released under the CERN Open Hardware License 1.1.

I had built one in the past out of white paper, but it was flimsy and the white paper made it too reflective. I hadn't thought about it again until our makerspace ( http://makerspace.org.uk) got to play with a Silhouette portrait.

I quickly realized it would be easier to cut with the portrait. I did one cut (of the outline and the windows). It still needed folding using a ruler and pencil. Then I had the bright idea to use the perforation setting to make folding easier.

The final change was to extend the window to make it easier to encapsulate the piece of dvd.

This instructable provides the file (in the silhouette studio software format) for cutting, and instructions for assembling and using.

Have fun.

Step 1: What You Will Need....

To make the spectrometer you will need:

black card
blank dvd
scalpel/scissors
things for fixing : glue, tape(clear and black)
optional:clamp for glue(I am using a heatsink clip)
wondering what's the cork for? keeping the scalpel safe

I have been using the silhouette portrait with its studio software.

Step 2: Cutting Out the Spectrophotometer Sheet

Setting up for cutting.

setting: card(plain)
set the cutting blade to 4 on the machine
use the (supplied) backing sheet for the card
turn on the silhouette
load the backing sheet by pushing it to the roller
hit the top button (looks like a graphed clipboard) on the machine. [steps 5-6 in the 2x speed 1st video]
then [send to silhouette] from the program
away it goes. [in the 8x speed second video]
hit the eject button
peel the card off the backing sheet

Mini_spectrophotometer.studio3
Download

Step 3: Assembly

fold as shown in the spectrograph diagram
leave the square window till last
tape all the other folds
look into the resulting box at the slit at the end.
1. is it free of any stray card? use the scalpel to clear it.
2. are there any light leaks(apart from the slit)? use the black electrical tape to seal it?
Now the interesting bit.
1. take the dvd
2. cut a quarter of it off with the scissors
3. trim a 2cm wide bit
4. keep this
5. separate the two layers of the dvd with the scalpel
6. keep the clear layer
7. CORRECT ORIENTATION:
  1. want rainbow to go in the same direction as the slit.
8. glue the first aperture down
9. now place the dvd layer over the aperture and fix it down
10. secure with the final flap

8.5x11mini-spec3.8.pdf
Download

Step 4: Using It

Three ways to view

use your eyes
- put the side with the piece of dvd up to your eye.
- look through while moving it near a indoor light source. Old style tungsten should give a rainbow, while fluorescent will have a few bands, and leds only a few)
to make a photograph
tape the spectrometer to a phone
- again moving it till you get a series of bright colored dots (or lines)
- take a picture.
- upload to http://spectralworkbench.org/upload
tape the spectometer to your webcam
- go to http://spectralworkbench.org/capture
- follow the instructions on the page.