serious help please!

[blink138]

hello members i am having a terrible time trying to collimate my c11
let me begin by saying i have collimated it before reading legaults(?) process

i have not mounted my c11 for quite a while but was amazed to see it not even in the ballpark when i checked it last night and for the life of me i was only able to make it worse ........... unbelievable!

this morning i read about collimation during day light hours and gave it a go and it seemed a little more intuitive to me and i seemed to get things a little closer .......... but, i have known about this for quite some time, my whole baffle tube can spin very easily in the corrector and has about 2mm of lateral (slop) movement when jiggled
i tried to video it on my phone but it would not download
when i twist it (no effort at all involved) i can see a thin "gasket" moving with the whole assembly on the inside of the corrector

this has been bugging me for nearly a year now people and it is beginning to get me down, i have saved up a lot of money to get what i have but my poor c11 is basically useless as is

help!
pat

[glend]

I suggest you make a Duncan Mask for it. They are not hard to make and provide precise collimation. However, if the scope is damaged, as it sounds it might be, that should be fixed obviously. Bintel is a Celestron Service provider I believe.

[Nikolas]

http://astroshed.com/observatory/c11saga/c11saga.htm
great article about the same issue as yourself

Also this video is useful on how to remove the corrector plate so you can check the inside, don't worry about converting it to a hyperstar but it can give good clues on how to "tighten" things up
https://www.youtube.com/watch?v=GXA7X5G_Ml8

[blink138]

thanks glen, not heard of a duncan mask i will check that out
i certainly have not damaged the scope in any way and for a number of years it was very good
pat

[blink138]

yes that is exactly what mine is doing nikolas, not sure if i have the nerve to strip anything down, but i may contact bintel for advice
pat

[multiweb]

If you have rotated the secondary it is possible you won't be able to focus properly depending how it was figured. One way to find its original orientation in reference to the primary is to look on its side or back. There should be a mark that you need to align with the 3 o'clock position on the primary which corresponds to the focuser knob side looking from the back of the ota.

[blink138]

thanks mark, i did not spin it around a number of evolutions, just one way and then tuther back to the same spot
mark i have read your stuff a couple of years ago stripping down your c11, is is bad that i can swivel the assembly round so easily? shoud it be fixed and immovable?
pat

[multiweb]

The secondary holder can get lose in the corrector. It's easy to fix. All you need to do is remove the corrector, tighten the secondary and put it back. Take note where all the shims are around the corrector (take a photo) and put them back in the same spots. Put the corrector in the same orientation as well. Very easy to do if you're methodical.