Collimation demo

[chiefshockey]

Hi Guys, i'm pretty new to astronomy and i'm trying to learn how to collimate my scope. It's a Celestron 130eq newtonian.

I've made a collimation cap, but i just can't seem to get it fully aligned or even if my cap is actually dead centre. 

Is there anyone in the Chilliwack/Abby area who would be willing to show me how to collimate? 

[Deleted]

Welcome Chief,  That scope looks nice online. (but I have no skills with EQ mounts)

For now a couple of questions.

1)  I assume it has a 1.25 inch focuser ? (not a 2 inch one)

2)  By collimation cap you mean a cap with a center peep hole to go over the focuser?  I've used 'caps' made from old film containers --- the lid is drilled with a hole in its center and the container's bottom is cut out then slid into the focuser.

3)  Does the main primary mirror have a center dot on it?

4)  Does the secondary (diagonal) mirror have any set screws behind it?

To get a feel for all the confusing reflections in the center hole, may I recommend clothes pinning a folded sheet of paper or cardboard onto one spider vane to block the view between the secondary mirror (diagonal) and the primary mirror.  Then, in the daytime with the scope pointed at a light colored wall, start to get familiar with the view through the peep hole without the primary showing.  Now you're looking to make sure everything in that view is centered, in line with the focuser.  Usually nothing there is amiss.

Once you've got that down, then remove the paper and look at the outer edge of the primary -- ignoring the reflection in that primary mirror.  The outer edge of the primary needs to be centered in line with the other previously seen parts (inside of focuser and outer edge of secondary)  If the outer edge of the primary (not the reflection in the primary) isn't centered then that's when you tweak the set screws behind the secondary to get the outer edge centered.  The secondary should still be pretty much in good alignment and that step usually isn't needed.

If all that is centered then only the primary's reflection needs to be centered.  And that is done adjusting the screws at the back of the primary mirror.

Let me know how you do and I can help you more if you need it. 

My laser collimator is for a two inch focuser so I only have my Chessire for a 1.25 which is even easier to use if the primary is center dotted.  I'm also available tomorrow or Saturday if you need assistance.  PM me if you like.

Darrell  604-853-4260. Abbotsford.

 

[craig]

hey hey i dont know if u have done this yet but their is some really good info on youtube www.youtube.com/watch?v=uU8wtWiz9R8 this movie uses your telescopes itself i use a lazer first to align it and then a Cheshire tool afterwards to double check. i have never done the method you are trying to do but whenever i need to learn something i goto you tube or ask Darrell.