JBEBT - 1.25" Spectograph Thingy

2021-03-02 I send this email:

The Perseverance landing was tense, but what is really going to be a stressfull, is the James Web Telescope launch this year...

Now almost a year later I designed this Thingy, inspired by the James Webb telescope (still cooling at this moment). Next week the first image stacking will take place. In a few more months it will be ready to take the first crisp pictures. The temperature on the hot side has gone up a bit, but hopefully the cold side of the shield won't affect the sensors.

The webcam used is a Logitech C615 HD Webcam and the SMD LED has been removed from the PCB. The location is D3 and it shows a + and - sign for orientation of the Diode.

The difraction grating I'm using now is from a guy in Israel, but since this is still a thingy in progress I might try other things like CDs or DVDs. So with this in mind I changed the design from having just a bottom cover, to having a closed bottom and a hinge.

PLEASE DON'T COMMENT ON THE SLDPRT FILES. I DON"T DO CLEANUPS ANYMORE AND HARDLY LOOK AT THE HISTORY OF DESIGN MYSELF AFTER IT IS FINISHED. WOULD I LIKE TO RE-DESIGN I JUST CONVERT ENTRIES AND MAKE A FRESH MODEL. SO CAN YOU !

Don't worry about the size. The hole is now 2,5mm so smaller when printed. A 2,5mm drill will do fine as a hinge. or any rod that hase the same diameter. I wouldn't drill beyond 3mm.

I will later add some electronics later that I use to calibrate the spectrometer. The frequency / LED can be changed by a push of a button and before an external light will show the on / off status, 3 LEDs will burn UV 395nm, Red 700nm and IR 940nm. Not sure how, but probably with a mirror I will reflect the LED's to a slit. Important thing is that there will be a little bit of light with all the frequencies. So coating the inside to reflect the light will be my first try.

Problem is I have a wife and 2 kids, so time is a luxury I don't have for these things...

Like the James Web this JBEBT will be able to detect red- or blueshift. To be able to see the amount of red- or blueshift emission lines must be detectable. So this might be a failed project from the start if the resolution of the camera / diffraction gratting / angle of attack isn't right.

So since I might want to tweak and add some adjustments. I need easy access to the camera module. Adjustment screws might be handy if it works and the part that I haven't created yet is the holder for the diffration gratting now with sticky tape "attached" to the camera.

So wait for my final upload, of test along with me :-)

UPDATE:
Diffraction grating holder for the webcam PCB Has been made notice the orientation on the Logitech C615 HD Webcam PCB. The angle is right for the 1000 line linear diffraction grating from www.rainbowsymphony.com When placing this grating you should never contact it with your bare skin !!!

The fit is now for a 1,25" but I would like to use it with my Tele Vue 8mm Delos, so I will design something to be used over an eyepiece. In the picture the PCB isn't glued yet and therefore I didn't calibrate the light. For callibration you can make the included tool, of just use some leds and hold them in the same place. Better is to have a single point of light.

Making this point there still should be a fixed slit-thingy so there is no shift over the horizontal line. Making it up as I go...