Assembly Day

All the parts for the spectroheliograph I am making have arrived from France over the past couple of weeks.  Today is a day of thunderstorms so I decided to start assembling this instrument.

The last parts to arrive were the optical parts...  two doublet lens assemblies, a tiny slit, and a holographic grating.  I needed to disassemble the 3D printed parts so I could assemble the entire instrument with the optical parts included.  Of course, I first cleaned up the room and removed as much dust as possible.

Once I assembled everything, it was time to connect it to a computer so I could make some tedious fine adjustments and then test everything.

The first obstacle to overcome was that the holographic grating was not in line with the rest of the assembly.  I needed to shim this significantly and it is still not right.  I might need to re-shim this part after more testing.  

Unfortunately, it is quite dark outside today with dark clouds changing the light significantly within seconds.  I was able to do some rough adjustments and see my first spectral lines indicating specific wavelengths.  In this case, below, we are looking at the lower end of the spectrum at the Calcium line...

I can't remember for sure but I think that in this photo, below, I moved up toward the Hydrogen alpha wavelength.  I can't remember if I moved all the way up to the top end which is at the Hydrogen alpha spectrum or if this is a bit below that near the Sodium line.  From the look of the lines (and in my inexperienced estimation), I think this is probably somewhere near the Sodium line...

I was only able to make some rough adjustments today so I'll need to refine those adjustments as well as get the collimation just right in the coming days.  I'm still learning about all of this stuff so there is no doubt that I have more learning to do before I understand how to do everything with ease.  I've been taking it one step at a time.

Fine turning this beginner custom instrument is rather difficult because the adjustments are more on the crude and coarse side.  Brighter and more consistent light will help though so I'm hoping for brighter sunlight to accomplish this task of fine tuning and collimation sometime soon.

I know the results shown in photos here don't seem like much but this data that is collected as spectral lines can be converted into images and that is my ultimate goal.  Before I can do that, however, I need to ensure that the instrument is properly collimated, adjusted and focused but I'm still working on that at this point.