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Public Lab Research note

Assembly pics for prototype "countertop" spectrometer

by warren | September 12, 2012 17:12 12 Sep 17:12 | #3760 | #3760

OK, folks asked, so here it is! This doesn't have all the part #s yet because we're trying to source very cheap ones, and also trying to find non-PVC parts where possible.

Don't worry -- this looks untidy but it's only the very first version of this model we've made -- we're in the process of finding final parts and then we'll do a nice clean version with new build photos. But this is quite robust and sturdy -- it holds a calibration quite well, even in my bike bag. (I guess that bears some tests... will do soon!)

A limited (and fast-evolving) parts list can be found here. Anyhow, without further ado, here are the photos:

DIY Spectrometer: webcam

The whole thing is built around a small, USB HD webcam, pictured. It helps that the webcams we're buying (from Syba) have square sides, so we can get precise angles.

DIY Spectrometer: imager housing

Here's the webcam inside a 1" Type-LB PVC conduit access port. We've switched all desktop models to this part because its rigid, standardized, and really pretty much perfectly shaped and sized. It's even water resistant!

DIY Spectrometer: interior

Inside the box -- this looks super messy, but as I mentioned, we're working on a folding black card-paper insert which will make this straightforward. Hopefully it'll even allow adjusting the webcam angle. This one uses an older camera and a lot of hot glue -- we were just figuring out the geometry.

DIY Spectrometer: arm assembly

Here you can see the myriad joints we used to build an arm -- this could be simplified or adapted to different mountings, different lights, etc.

DIY Spectrometer: base wiring

This is super messy for now, but it's because we're sourcing the final lamps, dimmers, etc and trying out different ones as we go. It's hard to fit everything in that little box; we may try switching to a larger one, or doing custom-cut faceplates so we can move the lamp further back.

DIY Spectrometer: lamp

And that's pretty much it for now! Questions? Suggestions? Even better -- post your own build photos! I know lots of you are building your own already...


I am working in a similar DVD-based webcam spectrometer to use in a telescope which gave me a CFL spectrum I already submitted to SpectralWorkbench. One great thing about this project is that has gone through much experimentation with setups to make it easy to anyone just to assemble it from a kit. Does it work with first order or second order diffraction?

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I think most of our kits use first-order. Second order is wider -- so you could maybe get better resolution -- but it's much dimmer, too.

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Thanks for the response warren. I will be posting in publiclab.org a summary of the work I am doing with my setup. Meanwhile the whole thing is being posted already at http://astrophotovideo.wordpress.com/astrospectroscopy-with-a-webcam/. One good thing on using the Syba webcam you chose for the kits is that the rectangular camera facilitates its alignment.

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