Nexstar 81 SE secondary and corrector plate issues

[MaxBlancke]

I am a pretty casual amateur, and usually only bring the telescope out for special occasions. We did so recently for the comet, and I discovered some issues.
Firstly, the secondary was loose, second, the garbage plastic mount for the star pointer was broken. We managed to get a decent look at the comet, but the collimation and alignment were not optimal.

I decided to make a mounting plate to put a better scope on it, as well as provisions to mount a camera later. I do have very good machine tools, so I am comfortable that I got at least that part right. I had to remove the corrector plate to get at the secondary, as it was rotating, and to replace one of the bolts on the front casting with a longer one to mount the front of my bar. I also discovered in the process that at some point a bit of moisture degraded some of the cork spacers.

Anyway, I am not confident that I have everything aligned properly on assembly. I made a couple of new spacers, and the corrector plate is centered on the tube to within a couple of thousandths. I tightened up the secondary, but do not know if it or the plate are oriented correctly. I suppose it is possible that the plate itself is not necessarily supposed to be centered on the tube, either.

I should have marked the orientation and position of the plate before removal, but with the degraded spacers, it might have already been off. I would like to set everything up properly. I have done a lot of work on antique rifle scopes, so I have some experience with optics, but not telescopes.

When I set up my rail, I set the scope down on it's front casting on a surface plate, and mounted everything parallel to the tube. My front and rear mounts were milled to match the outside radius of the castings.

Anyway, it seems sort of stupid that the corrector plate is held in place by a cheap plastic ring, and that any drop of water that lands on the front of the telescope will inevitably enter the tube. Water damage on a telescope that has never been left outside for more than an hour or two, and ever exposed to rain, seems silly to me.

Anyway, i appreciate any help that I can get.

[JayTee]

Hi Max,

Welcome to TSS.

In 4 more posts, you should be able to attach pictures to your posts. Pictures would certainly help in making recommendations.

To get past that hurdle, just go to the welcome forum and say Hi! to 4 newbies like yourself.

Cheers,

[MaxBlancke]

I did not even think of posing images, although I ought to post some of my rail when it is finished. There is nothing visibly wrong with my telescope, in the sense of something I could photograph. The view just does not seem as sharp as it should be, and setting up the corrector plate and secondary mirror feels like the solution.