Hi all
I've taken my M-210 apart for a service. It hasn't had one that I know of, and the focuser has become a little notchy, rather than moving with the liquid-smooth motion that Tak focusers are known for.
Given that the helical focuser itself is brass, and there wasn't much of the old grease left on it, what would one recommend to re-grease it with? A silicone-based grease or oil? The original grease is your typical yellow/orange grease colour - not black or white as per lithium. I don't want it to run when hot (as they invariably get when at star parties during the day) and I don't want it to increase in viscosity too much either.
The only other part that needs a decent smear is the main central baffle tube, around which the outer sleeve connected to the mirror cell itself slides. It's a very close lapped fit. It certainly doesn't want to become gluggy.