I have long been disconnected from astronomy because of that I have good friends
. A friend gave me a C14 optical tube, for I try to improve the quality of my images of Jupiter.
But the C14 was poorly constructed. Once completely disassembled, I found that the primary mirror was displaced from its axis and tilted several millimeters, so it was impossible to collimate, and always showed a severe astigmatism. Furthermore, the grease had liquefied, and was converted into oil, dripping over the mirror.
I have spent my time devoted to astronomy to reconstruct the optical tube, sticks it with black velvet, building a colimable barrel for the primary mirror, building a supplement to the position of the corrector and the secondary mirror and creating a system that allows me collimating primary correctly. It was hard work, but I think the results are worth the effort.
Now I just need cloudless nights.