I picked up a Cave Astrola 8" f/4.5 R.F.T. a couple of months back, and I have truly enjoyed using it. I was fortunate enough to find a scope that had the mirror refigured by Steve Swayze and recoated by Spectrum Coatings in late 2018. By all casual "testing" and perhaps more importantly to me, eyepiece results, this is a very good mirror now.
But there's one problem. The focuser has been replaced with some mediocre old single-speed focuser. I love the mirror. I love the scope on my CGEM. I LOVE the rotating tube rings. But I hate the focuser.
Besides it's awful "feel", I fear a far more significant problem: I think the drawtube is too long. Even without a collimating eyepiece in the 2" focuser drawtube - with nothing in the drawtube - I cannot see the edges or clips of the primary. Near as I can tell, I have an effective-6" mirror.
Then again, I know just enough about this to hurt myself....
I know it's probably heresy, but the mirror is nice enough for me to warrant spending up for a Moonlite focuser or similar, and it was already a functional restoration, not an authentic restoration. With the rotating rings and a focuser with precision feel, everything I physically touch while observing will be "very nice" . But does anyone have experience or suggestions on what works as far as drawtube length and such?
Some technical information that I know: The mirror's been refigured at 36-1/8" (f/4.52), from the original 36-1/16" (f/4.51). It has an Astro-Systems 1.83" secondary. Am I foolish to think the starting point is as simple as removing the focuser and mocking up a cardboard drawtube to hold in the OTA hole? To see what I can get away with? Also, part of my fear is that the secondary is the wrong size, but figuring that is above my pay grade.
What say ye, collective brain? I'm all ears.