I have been playing around with different ideas for the past week on physical designs for the spectrometer...  Aside from the geometry, and other design aspects.. I needed to develop a physical 3D printable case to fit the optics in, etc..  So here are a couple renderings on what I think might be the start of the final idea..  :)   It's very simple right now, no details.. just basic placement and shape...  But from everything I can figure, and a whole lot of attention to whether it will fit into the case with all the other parts and optics...I think this should work well.  

Here are the renderings...

Like I said..pretty basic right now..  I think I got enough from the testing with the test stands that I made in my previous round that I am pretty happy with the geometry and focal lengths, etc.. etc.. etc.....   I will be adding adjustable mounts for the optics to allow for fine tuning, etc.. and might be adding a stepper motor for both the diffraction grating and the CCD array..  I'm very interested in the idea of increasing the resolution by taking a sample, then sliding the CCD a tiny bit and taking another sample, etc.. and adding those up...  Theoretically, that should provide for a pretty decent gain in resolution... and actually might be very useful in noise reduction since you could take several dark samples with the CCD in multiple positions then take subtract that info from the final... Just a thought for now, but I would love to hear other opinions...!

I would also love to make this portion of the system functional in its own right, so people could use it as a regular spectrometer if needed..  

As a side note.. I have been looking at different light sources to calibrate and test with...  Something that anyone can find, and get without spending more on it than they did building this whole thing..  

So, I spent a while looking and the best option I could find were spectrum tubes that you can buy on either Amazon or eBay for about $15-$20 a piece..   Unfortunately, the power supply is about $165....

Having said that... I'm trying to find alternatives to the power supplies they offer... My first thought was a neon sign transformer...but I have read a lot saying that isn't a good idea due to inductive loading and so on.. causing the tube to either expire quickly or actually overheating and possibly exploding..  I also hear the tubes require a sort of kick start..  If they run at 3kv or so, they might need a 5kv bump to fire properly...  I've been searching for schematics, etc.. but if anyone has a pointer, I'm all ears!

As always, I would love to hear any comments you have!