AstroSystems Laser Collimator with Barlow arrived...problems

[GeoffW1 (Geoff)]

Originally Posted by Omaroo

LOL! No probs Matt. It's just that last time this unit was discussed someone refused to believe that it wasn't constructed the same as the type you've pointed out

Hi,

If that's me you mean, you missed the point then, and you still are.

If not, I think it's an unnecessarily snide remark anyway.

Cheers

[Omaroo (Chris Malikoff)]

Geoff - I see we're at it again. http://www.iceinspace.com.au/forum/....milies/lol.gif

Again - with all due respect, have you yet directly and actually used one of these actual units in question? Have you had one in your hand? A simple question with a yes or no answer!

"you missed the point then, and you still are." - who's being snide?

Sorry DJVege - I've had enough of this subject - apparently there are experts who have never used one that will answer your questions, but what the hey!

Cio

[GeoffW1 (Geoff)]

Originally Posted by Omaroo

Geoff - I see we're at it again.

Again - with all due respect, have you yet directly and actually used one of these actual units in question? Have you had one in your hand? A simple question with a yes or no answer!

"you missed the point then, and you still are." - who's being snide?

Sorry DJVege - I've had enough of this subject - apparently there are experts who have never used one that will answer your questions, but what the hey!

Cio

Chris,

We're only at it again if you want. I replied only under some provocation from you. I'd certainly like to move on, and I want you to also. I agree all this has definitely come to be a complete waste of space.

Whether or not I've had one of your favourite laser units in my hand has nothing to do with it - read my earlier posts. I am quite happy to accept the unit has any marvellous features you claim for it. Each to his own.

I have made no claims at all to being an expert, just someone with a bit of experience to share.

I'll repeat for your benefit (you seem to be the only one who needs this) -

I think it is really useful to be able to give your laser collimator a collimation check yourself.

If you cannot do that check, you may suspect the unit requires collimation, but how will you know for sure? Again, if you send it off for a fix, how will you know for sure it is now OK when you get it back, or indeed if it is any different at all? That's my perspective. No aspersions intended about this laser unit in particular.

There it is in a nutshell. Just my opinion, never was anything else.

Now, can we move on? Without further derogatory references to my opinions (the ones I am entitled to)? Please?

Cheers

[DJVege]

Hey guys,

Ease up GeoffW1 and Omaroo. No "war of opinions" required here.

MY RESULTS!!!

THE ASTRO SYSTEMS LASER COLLIMATOR IS COLLIMATED!!! It passed the straight line test, and the tube test. Well, I think it did. I put it in the tube, I didn't bother centering it, Omaroo. It was about a cm from the middle mark on the primary...I turned it in the focuser tube, and it stayed exactly there!!!

[Tannehill]

good, that's a relief.

Try collimating the secondary mirror with the primary laser beam, then the primary mirror with the barlow-attachment on the laser. Don't use that merge-the-return beam technique. See, then, if the chesire agrees with the barlowed laser re the primary mirror.

s

[Omaroo (Chris Malikoff)]

Originally Posted by DJVege

Hey guys,

Ease up GeoffW1 and Omaroo. No "war of opinions" required here.

MY RESULTS!!!

THE ASTRO SYSTEMS LASER COLLIMATOR IS COLLIMATED!!! It passed the straight line test, and the tube test. Well, I think it did. I put it in the tube, I didn't bother centering it, Omaroo. It was about a cm from the middle mark on the primary...I turned it in the focuser tube, and it stayed exactly there!!!

Good one DJ - and so it should be. That's what you pay for when you order one, a company-guaranteed instrument that is in alignment out of the box. Mine was the same - the beam is straight and well-defined. With the barlow on, my beam stays put when the unit is twisted - right back to the barlow on the diffused return beam - which is obviously double the distance.

[DJVege]

Originally Posted by Tannehill

good, that's a relief.

Try collimating the secondary mirror with the primary laser beam, then the primary mirror with the barlow-attachment on the laser. Don't use that merge-the-return beam technique. See, then, if the chesire agrees with the barlowed laser re the primary mirror.

s

It doesn't. This is the techniqe i tried first when i got this astro systems laser collimator. I'm going try, hopefully this weekend, to move the secondary into the centre of the focuser, as I think this is the problem. Once that's done, I'll try the technique above, and see if the cheshire agrees. If not, I'll be back on here, asking someone to help me!!

Will report back once it's done!

Thanks guys!

[Omaroo (Chris Malikoff)]

DJ - are you sure you want to do that? Moving the secondary in relation to the focuser is going to also result in a shift between the secondary and primary... which you should not want.

Logic would state that you've replaced the focuser assembly with another - so any misalignment would more than likely be as a result of this exercise. Are you absolutely certain that the relationship between the focuser and the secondary's offset centre dot is still correct? The axial centre of the focuser should be pointing at a slightly-offset centre of the secondary - not the true centre. It will still work if it doesn't, but you may see an offset secondary (as you have). David Kriege's book explains it all if you have access to a copy.

Can you replace the new focuser with the original (accurately) and see if you get what you're used to in terms of cheshire alignment?

[Glenhuon (Bill)]

Think I'll sit back and listen now, looks like you guys have a fair bit more experience than me. Probably learn something new

Bill

[DJVege]

Hmmm...In actual fact...i'm lost!

I thought, looking down through a cheschire, the secondary mirror should be centered under the focuser (or through the tube I'm looking through).

Maybe I should just wait till someone in the know can take a look. ??

I'll have another play/look tonight and report back.

[Omaroo (Chris Malikoff)]

DJ - start by going back to your original focuser for a bit. Go back to basics and see if you get the same collimation result that you expect. You've proven that the A/Systems unit is in collimation and its beam is straight - so there are other reasons why the two systems don't agree..... or do they? Maybe the new focuser tube placement has off-centered it in relation to the secondary, and it's only because you physically sight through the Cheshire that you're noticing it now.

[DJVege]

If the new focuser HAS off-centered it...what do I do? Don't I use the set screw and move the secondary back?

[Omaroo (Chris Malikoff)]

Originally Posted by DJVege

If the new focuser HAS off-centered it...what do I do? Don't I use the set screw and move the secondary back?

It'd be better to investigate why the new focuser centres in the tube opening differently. Did you use the original focuser base with the new 10:1?

[DJVege]

Sorry for the late reply, but I had a very busy weekend.

Yes, I used the old focuser base with the new 10:1 focuser from Bintel.

[DJVege]

Omaroo, sorry about not getting back to you yet. Have been very busy lately; getting between 3 - 5 hours of sleep a night. But will play with the focusers today and get back to you.

Thanks and sorry again.

[Omaroo (Chris Malikoff)]

All in your own time DJ - no worries here

[Tannehill]

I'm keen to learn if the secondary adjustment fixes the disagreement between barlowed laser collimator and chesire.

I took the liberty of generically describing your observation (the barlowed laser and chesire do not agree) to the gurus on the telescope collimation yahoo group. There was no easy explanation from them, either. One of the most experienced fellows did point out that the collimation of Mak-Newts is a bit specific; the corrector plate needs to be aligned as well as the primary mirror, and there was not (to his knowledge) a well described way to do this.

I'm sure there is some element of your observation that we're missing; hopefully your secondary adjustment resolves the problem. It's just that, as I continue to learn the optics of collimation, I can't figure out how the disagreement between the chesire and barlowed laser could be anything other than an odd flaw to the chesire, the focuser tube (piece is not sitting in straight), or what have you....and not the secondary.

Please keep us apprised...

regards

scott

[DJVege]

Uhhh!! You know what...my new theory is that I just don't know what to look for in collimation with this Mak-Newt, and I'm going to wait till I can get a pro to look at it for me...and tell me where I'm going wrong!!!

Phil, I find out today if I get that job or not...if I do, I'll be up your way in no time!!!!!!!!!!!!!!!!!!

[DJVege]

Unfortunately, I didn't get that job!!

Anyone in Brisbane who I can visit with my scope and who can tell me what I'm doin wrong? Pleeease?