Collimation.

[iainmax]

Good evening fellow gazers.

I decided I just had to strip down my scope to clean the mirror as it was in obvious need of a fresh clean. All went went well until I started to undo the primary mirror. I only needed to unscrew 3 screws but ended up unscrewing 6 of which I believe 3 are for collimation purposes. To cut a long story short, the primary mirror is now spotless and i've added a centre dot to the mirror after following a tutorial. I would like to collimate the mirror myself and would appreciate any suggestions on where I might find a decent tutorial to help me achieve this. I have no special tools, only what came with the scope so if this can be achieved with what I have that would be brilliant. If you recommend I buy something which is useful for the future then that's fine too.

There are a number of tutorials on the web but some of them seem quite complicated for me so any advice is greatly received.

Thanks guys.

Iain

I have a Sky-Watcher 130 (not sure if it's M or P)

[LukeSkywatcher]

There is a collimation tutorial on SGL somewhere by fellow SGL member Astrobabe. Its so simple to follow. It has become a bit of a "bible" at this stage. Do a search for it. I cant find it off hand. Maybe someone else can point you in the right direction or have other advice. 

[Night Hawk]

This is where you can find it;

http://astro-baby.com/collimation/astro%20babys%20collimation%20guide.htm

[pevsfreedom]

This is where you can find it;

http://astro-baby.com/collimation/astro%20babys%20collimation%20guide.htm

I had a question about that article,

there's quite a lot of info about adjusting the secondary, etc. but for my scope it seemed like it didn't apply. Was most of that info for only if your spider vanes are adjustable? Like my secondary has the 3 thumb screws, I set it up so I could see all 3 clips in the focuser and in 2 minutes I was done and the article talks about taking an hour to adjust it properly, etc. and there's all these steps about using colored paper to better see it. I found it to be very easy to adjust it (I think). Makes me think that only applies to certain scopes and not mine? Just curious. 

[LukeSkywatcher]

I had a question about that article,

there's quite a lot of info about adjusting the secondary, etc. but for my scope it seemed like it didn't apply. Was most of that info for only if your spider vanes are adjustable? Like my secondary has the 3 thumb screws, I set it up so I could see all 3 clips in the focuser and in 2 minutes I was done and the article talks about taking an hour to adjust it properly, etc. and there's all these steps about using colored paper to better see it. I found it to be very easy to adjust it (I think). Makes me think that only applies to certain scopes and not mine? Just curious. 

Most of what is in the guide can be applied to most scopes. The only scope type that the guide has no bearing on is refractor scopes as these pretty much dont need collimation over their life. Just pick out that parts that mean something to you and your scope and follow those steps. Even SCT's may need collimation at some stage and this is done at the front of the scope with 3 screws that are in the middle of the glass corrector plate. 

Your scope is a 10" Dob and as such will need collimation from time to time on the primary mirror. I'm sure your scope has 6 screws on the back..............3 are for collimation and 3 are to hold the mirror in place.

I may be wrong. I'm sure someone else can advise you. Ive collimated one of my scopes once since ive owned them and that was just to see how to do it. It didnt need it. My scopes travel less than 20ft any night of the year, so collimation is not something i worry about. I only have 1 scope (Heritage 130P) that could at some stage need collimation, but its spot on even after 6 yrs of use. 

[pevsfreedom]

I collimate it every time i use it, mostly just the primary mirror. It's big and bulky and gets bumped a lot and is always off before I collimate it. I was just confused the first time I read it because it felt like the secondary mirror collimation was a lot easier then what the article made it out to be. Maybe KISS (keep it simple stoopid) applies here?

[LukeSkywatcher]

The bigger the mirror, the more often it needs collimation. I dont think secondary mirrors need it as much because they are much smaller. 

[iainmax]

You guys are awesome. Thanks for the link. I'll have a proper look at it tomorrow.

Cheers.

Iain

[Peter Drew]

Hello Iain. You know where we are!