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collimation of the secondary mirror.


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Hi all.

You would have thought I figured out collimation by now, but here I am. :happy7:

Now I just realized my skywatcher 130PDS needs collimating, so I attempted to adjust the secondary mirror, but I just couldn't figure it out. I don't understand how the secondary mirror moves, which screws move much directions, why when I try and adjust it doesn't seem to do anything, and how I should be aligning the mirror in general. I have also heard that in fast newts I should be offsetting the secondary mirror, because the light cone doesn't quite match up when its perfectly aligned.

I have a Cheshire eyepiece incase you were wondering.

:help:

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For the offset thing, someone told me the mirror is installed on it's support with the offset and there is nothing to do other then following the Astrobaby's guide to collimation with the suggested tools. Once you learned how to play with the screws, it's not hard anymore.. and takes less then 15 minutes to reinstall the secondary from scratch.

To help, I put a tiny film of all purpose 3 in 1 oil on each of the screws, it's much smoother that way then previously.

My newtonian is F5 and I can see the offset just like in the Fast / Slow Telescopes section from the guide, everything is fine.

 

 

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1 hour ago, N3ptune said:

For the offset thing, someone told me the mirror is installed on it's support with the offset and there is nothing to do other then following the Astrobaby's guide to collimation with the suggested tools. Once you learned how to play with the screws, it's not hard anymore.. and takes less then 15 minutes to reinstall the secondary from scratch.

To help, I put a tiny film of all purpose 3 in 1 oil on each of the screws, it's much smoother that way then previously.

My newtonian is F5 and I can see the offset just like in the Fast / Slow Telescopes section from the guide, everything is fine.

 

 

Good idea! May I suggest that a good, thick grease, preferably something Teflon-based like SuperLube, would be better. Oil can drip more readily than a viscous grease.

I've found oil is destined to go where it's not wanted. Sneaky stuff that is it's nature...

Dave

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I accept your suggestion of using grease :p I would still apply a very insignificant amount of grease and wipe any excess with a kleenex. Ill have a look at that the conditions or the screws next time I dismount my secondary, perhaps to clean the mirrors in the near future.

Oh! I see Super Lube has a nuclear grade grease, it's possible to buy it in a 30 lb Pail, code number 42130 this should be enough. :icon_biggrin:

http://www.super-lube.com/nuclear-grade-grease-ezp-55.html

But I can't say which one is Teflon based.

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