https://www.youtube.com/watch?v=FnpDfYSpLNo

How do you see the pattern of the polar scope made by skywatcher for the EQ3-2/EQ5?
The lighter sold by sky watcher is too thick, it doesn't allow to brake the dec. axis without removing it.
I designed this lighter within 15mm, which allows you to put the cap on it to protect the polar scope from dust and still be able to brake the dec. axis later on.
The circuit is using 3 red LED (5mm 20mA), a SPST switch, a NPN transistor (MPSA18 but any NPN will do) a 5k trimmer, a 220R resistor and a DC jack.
Circuit is designed for 12V input which I get through the DC jack (center positive).
2 M3x8mm screws hold the cap. LED, trimmer & switch are glued.
It's kind of hard to take the lighten pattern with a smartphone, but the result is very satisfying, homogeneous red hue on all the field.
Made for my NEQ5 mount (35mm opening), to be tested on other models. (EQ8, star adventurer....)

Creality

Ender 3 Pro

No

Yes

0.28

25%

For good adjustments, please be sure of your printer settings. I had to manually remove some material for the cap to fit it on my previous design. The uploaded version has a slightly bigger opening for the cap.
I printed it from the flat base to the LED case, which wasn't the smartest thing (lots of support hard to remove). I guess the best way would be to print it upside down.
Holes aren't threaded, they're 2,9mm. On my printer the resulting hole is around 2,8mm in diameter, which is fine for manual threading with the screw. Be warned.

Clear skies!