What Collimation tool to buy

[Blackant (Ant)]

Thanks guys, this looks like the one I'll go with:

http://www.myastroshop.com.au/produc...asp?id=MAS-133

Seems to be a good compromise between cost and quality, from what I've read on the forum Skywatcher seems to be a good brand?

Thanks for the hints on size and the contact trick too Erick

Kind regards

Ant

[Starkler (Geoff)]

My thoughts on collimating tools:

Lasers - As said elsewhere only good for touching up an almost collimated scope. Must be a quality (read expensive) unit, as cheapies are diabolical to adjust and get right on a V-block.
No function for aligning the secondary under the focuser. You WILL need to do this sooner or later on cleaning your secondary mirror or otherwise disassembling your scope.

Catseye teletube: All in one cheshire sight tube, but I find the cheshire function hard to use in poor light when setting up around dusk. The reflective ring isnt anywhere near as bright as other models which have a window and a 45 degree slanted ring.

Skywatcher cheshire combo tool: The one I have came with a slightly bent crosshair wire. The Orion one appears to give a much better fit in the focuser.

Andrews cheshire: Too short to be useful as anything but a cheshire for final primary mirror alignment touch ups only.

I have read elsewhere that the Astrosystems lightpipe is a great choice amongst 1.25" combo tools. Peter Read of SDM may be able to get one for you.

[TrevorW]

I've used tools and I've seen tools used and I stand by what I said and as a beginner the best way to learn about collimation is doing it by eye IMHO especially for the smaller mirror sizes we use.

This is the way I taught myself from books and articles and I would say a lot of others did too. I'm not denying using a tool helps however it should be used as an adjunct to visual collimation.

FYI please refer these sites

http://www.piscescs.com/astro/collimat/notools2.html

http://web.telia.com/~u41105032/myths/myths.htm

As too the worst piece of advice, I don't think so.

Regards

[GrahamL]

I found the crosshairs a pain geoff I thought they were to thick.
I also had had a camera threaded 1.25 "adapter that I thought might of had some build issues as the skywatcher combo tool never seemed a snug fit in it .. though it worked ok .. and its new owner dosn't seem to have a problem with it..my andrews cheshire does work as a sight tube in my scope ..just .. I bought the skywatcher tool thinking it wouldn't .

Yeah to understand whats going on I found that no tools article most helpfull trev .. .. sometimes I dont bother with my cheshire If i can see things are pretty close .. you will need some tools for collimation and some info to help understand what your trying to do and how to do it. imo. .. that article well takes care of the info part

cheers graham

[Blackant (Ant)]

Hey all,

Changed my mind and just finished ordering the Orion Collimating tool online, should hopefully get here in the next couple of days. I read a few more reviews and people only seemed to have good things to say about it.

Thanks for all the help and advice, having all the theory that people have posted for me is gonna be really helpful. Last time i gave it a stab I only had the vaguest idea of what I was doing and why

I'll have a go with the 114mm York skyrover I've got, and then when my tax return arrives it will be time for the 8" Dob

Kind regards

Ant

[ausastronomer (John Bambury)]

Originally Posted by Blackant

Hey all,

Changed my mind and just finished ordering the Orion Collimating tool online, should hopefully get here in the next couple of days. I read a few more reviews and people only seemed to have good things to say about it.

Ant

Smart Move. The Orion Collimating tool is only $20 more expensive than the Skywatcher, but is a lot better quality with much tighter machining tolerances. The Skywatcher is in fact a poor quality clone of the Orion tool.

Cheers,
John B

[wavelandscott (Scott)]

Originally Posted by ausastronomer

Smart Move. The Orion Collimating tool is only $20 more expensive than the Skywatcher, but is a lot better quality with much tighter machining tolerances. The Skywatcher is in fact a poor quality clone of the Orion tool.

Cheers,
John B

Agreed, you are making the right choice!

[bmitchell82 (Brendan)]

Yes it does work for what i need it for, and collmination seems to be fine for 30 min dslr exposures! though i must agree those gastly cross hairs :S when i got it i attacked it after figuring out it didn't help with a screwdriver now its all happy! thankyou once again

Originally Posted by nightstalker

I found the crosshairs a pain geoff I thought they were to thick.
I also had had a camera threaded 1.25 "adapter that I thought might of had some build issues as the skywatcher combo tool never seemed a snug fit in it .. though it worked ok .. and its new owner dosn't seem to have a problem with it..my andrews cheshire does work as a sight tube

[Starkler (Geoff)]

The crosshairs are for aligning the secondary tilt. You adjust the secondary so that the crosshairs align with the primaries centre donut and this ensures that the optical axis is square with the focuser.

Ripping them out is not recommended. The trick is to get your eye to focus on the centre spot and see past the crosshairs.

[Rick Petrie]

Hi Blackant
With the Orion collimating tool the cross hairs are blurry with your eye up close. If you position your eye away a little from the hole, it is easier for your eye to focus on the cross hairs to position the centre spot on the primary. It won't take long to find the ideal position.
Once you have adjusted the secondary mirror, the primary can then be adjusted to align the reflection of the cross hairs over the centre spot.
Wahla collimation!
Cheers Rick

[bmitchell82 (Brendan)]

hehehe well i actually use the outside rim of the colmination tube it proves to be rather accurate because if you can see any part up the tube your seconadary isn't right, tilt or rotation. then you place the primary mirror spot in line and your done. doing it this way my home made laser pointer which is collminated to 15 meters is dead on. the cross hairs only made getting accurate collmination almost imposible as it obscures the primary spot (not that its all that accurate anyhow being so thick. untill i get a cats eye i wont be to worried.

[Blackant (Ant)]

Thanks everyone, my orion collimating tool arrived yesterday, and it's definitely a nice, solid looking bit of kit. I had a bit of a play with it yesterday, and spent a bit of time familiarizing myself with all the different parts of my telescope for collimation. Thanks for all the info in this thread about general collimation, it was really helpful

Now the problem, my primary mirror has no central dot or doughnut

This means I'll have to take the mirror out of the back, mark the centre of it and put it back in. I'm going to use some of those little doughnut type stickers you use as reinforcements on sheets that go into a ring binder.

I just wanted to check I'm unscrewing the right screws to take the mirror out

Here is a picture of the ones that I think are right:

http://farm4.static.flickr.com/3407/...ab84ff4d_o.jpg

If anyone has any easy links to the best way to mark the centre of the mirror as well that would be appreciated.

The only other screws around are at the bottom of the telescope, and to me they seem to be the actuall collimation screws. The ones with the phillip heads and springs are the collimation screws, and the ones with the allen key heads are locking screws to use once collimation is correct:

http://farm4.static.flickr.com/3650/...82bc99bd_o.jpg

Thanks for any advice. I'm quite happy to take the mirror out and mark it, I just want to make sure I'm undoing the right screws and seeing if there is an easy, effective way to mark it

Kind regards

Ant

[Don Pensack]

Though this is version 1, and I've since released version 3 of this article,
this might help to get you to visualize what's going on:
http://www.iceinspace.com.au/63-390-0-0-1-0.html
Send my your email in a private message, and I'll send you the updated v.3
Don

[Blackant (Ant)]

Originally Posted by Don Pensack

Though this is version 1, and I've since released version 3 of this article,
this might help to get you to visualize what's going on:
http://www.iceinspace.com.au/63-390-0-0-1-0.html
Send my your email in a private message, and I'll send you the updated v.3
Don

Thanks for that Don, the article looks great

I'm gonna give it a go tonight after the kids are in bed. It's the first clear night I've had down my way for nearly a week, so any luck I'll have it sorted out in time to have a look at the moon before it sets.

Kind regards

Ant

[Blackant (Ant)]

Just got back inside, and yep I've rejoined the land of telescope users

After reading through all of the info pointed out to me on here, I pulled the mirror out, put a dot in the centre and then used my new Orion tool to collimate the telescope. Took it outside real quick as the sky was starting to cloud over, pointed it at the moon and hoped for the best

To be honest, I wasn't to hopeful that it was gonna work alright, it seemed all a bit to easy using the tool compared to last time I'd given it a go but wow, twiddled a bit with the mount and the focuser and all of a sudden the moon leapt into clear relief
I was using my highest power eyepiece, a 9mm with a 2x Barlow and the mountains and craters were just so clear I felt a bit stunned to be honest. The fact that the mirror didn't have a centre dot on it may mean that it had never been collimated properly at all, but anyway I know I've never seen the moon through it that clear before.

I can imagine the real test will be when I start trying to look at DSO's like 47 tuc, but that will have to wait till tomorrow when hopefully the sky clears up a bit

Regards

Ant

[bmitchell82 (Brendan)]

congratulations

Collminating isn't hard its just daunting! but after a few times of doing it correctly youll be happier than a pig in mud

[Blackant (Ant)]

Thanks Brendan

We just finished our tax return, and it looks like an 8" Dob is still on the cards

Just have to hope it stops raining by the time it arrives...