I miss film cameras. And those canisters were handy for a great meany things. So if you don't have access to a film cap, how about the cap from a pill bottle? find one that fits tight over the eyepiece tube. The center is also often already marked with a dimple. That's what I made mine out of. You may have to notch it for the rack and pinon gear though, but that's not a big thing with a sharp utility/exact o knife.
What a great solution, thanks.
I am waiting for my colimation eyepiece, it has shipped and hopefully here by the end of this week.
Another semi related question for everyone. When I move my dob I need to it in two pieces.
What I have been doing which maybe is not great is put the tube on it's tail on a sheepskin rug. effectively nthe locking bolts is kinda what it stands on but being a deep rug there is some support around the ring.
In hindsight this will affect collimation, should I make a triangle stand or lay it flat?