Anyone recommend Andrews Laser Collimator

[mbaddah (Mo)]

Hi everyone

I'm interested in purchasing this laser collimator, would you recommend it?

http://www.andrewscom.com.au/site-co...-guansheng.htm


I've never collimated before but seen videos on how to collimate using the laser. Your help is greatly appreciated, thankyou.

Regards,
Mo.

[Nevyn]

I have one and it does the job it is supposed to do. I'll recommend it!

[Glenhuon (Bill)]

I have one too, works great, don't know how I managed without it, makes collimating so much easier and quick.

Bill

[erick (Eric)]

Originally Posted by mbaddah

Hi everyone

I'm interested in purchasing this laser collimator, would you recommend it?

Yes!

But make sure you search for all the threads on laser collimators on this site - lots of useful information. Eg. collimation of the laser collimator itself; using it in conjunction with other tools since the laser doesn't do everything; barlowing the laser for an improved result.......

[mbaddah (Mo)]

Originally Posted by erick

Yes!

But make sure you search for all the threads on laser collimators on this site - lots of useful information. Eg. collimation of the laser collimator itself; using it in conjunction with other tools since the laser doesn't do everything; barlowing the laser for an improved result.......

Maybe not recommended than for a beginner like me if requires collimation itself ?

[Starkler (Geoff)]

Originally Posted by mbaddah

Maybe not recommended than for a beginner like me if requires collimation itself ?

For a newtonian I would definitely recommend a cheshire/sight tube combo tool over a laser. The Cheshire is everything you need to get it right whereas the same cannot be said for the laser.

[Kokatha man]

I'd definitely second Geoff's comments - not that he needs my seconding; but as someone who hadn't collimated for over 30 years I went back into re-learning mode only recently, and reckon it was just about on par with having never done it before.

I should say that my scope never held its' alignment for 30 years.....but I will say my dear old 8" newt on 2&1/2" galvo water pipe EQ mount/pier bore some uncanny resemblances (not optically!) to these Obsessions. Rosewood finish open timber truss etc: and whilst the action of obtaining alt-az motion via the threads of the pipe sounds bizarre it was actually extremely smooth and accurate owing to the very fine thread pitch and thus extremely limited "bearing play" over the half-revolution required from each axis. I reckon they were the dob's of EQ's (before) their time.

But I digress: from a noobs (virtually) point of view, and as I posted elsewhere, I found that when using the Orion sight tube/collimator, that getting the secondary appearing as circular as possible in the focusser tube (as well as centred in it) was a most important preliminary step before adjusting the secondary's screws/knobs - then adjusting the primary. However, on adjusting the primary I then needed to go back and start again with re-centring and "circularizing" the secondary in the focusser and then back to the primary.

Although it at first seemed as if I was back to square one, in going through the procedure again (and again!) I began to realize that the reiterating of this process a number of times brought the collimation up to a high degree of accuracy; subsequently confirmed by extremely good diffraction ring patterns in star-tests.

I should mention that I had deliberately put everything way out initially, as a "sink or swim" challenge: though of course I now only require tweaking to keep it collimated.

I'd be interested to hear what wiser hands think of my method/conclusions above?

Won't get into the laser Vs sight tube/chesire debate (not qualified) except I'm glad to say that Bintel got the latter before the former and I took the sight tube/chesire!

Regards, Darryl.

ps - did that Andrews tool(?!?) provide any use Eric?

[leon]

No..but i'm not going there.

leon

[ving (David)]

cheshire for a newt... but i wonder if it would be easier to use both? i have hear of a 2 in one i am sure...

[Paddy (Patrick)]

I have what I assume is the same model from Bintel and find it very easy to use, especially as you can collimate the primary of a big newt from the bottom end of the scope. I also use it to collimate the secondary (once the longitudinal position of the secondary is right). It doesn't seem to need collimating itself as the laser seems fixed in the unit that I have. I have tested it by looking for any wander of the laser as I rotate the collimator.

[rmcpb (Rob)]

A combination of the Cheshire and laser is a great aid to collimation. When the initial collimation is achieved with the Cheshire then the laser is a great way to quickly determine if anything has moved and needs tweaking.

[srv]

I have ordered one today
so that I can setup my 10" GSO dob.
I also got a Cheshire: 1, because I want to learn to do it manually and 2, as a double check.

I'll let you know how it goes. Hopefully they get here before the weekend.

[Solanum]

I bought a Cheshire/sight tube from Andrew's and it did it's job. The main problem I found was that the tube is too short to focus (your eye that is!) on the cross hairs, but the collimation was reasonable. I now have an Astrosystems laser/barlow collimator which is just great. They are available from SDM Telescopes now if you don't want to deal with the US directly.

When I got it I collimated with the Cheshire as well as I could, then used the Astro Systems laser, and the collimation was close but by no means perfect, so the Astro Systems won the day. There is a noticable improvement in the view with my better eyepieces since I've been using it too. Clearer, more detail and rounder stars.

Ev

Originally Posted by mbaddah

Hi everyone

I'm interested in purchasing this laser collimator, would you recommend it?

http://www.andrewscom.com.au/site-co...-guansheng.htm


I've never collimated before but seen videos on how to collimate using the laser. Your help is greatly appreciated, thankyou.

Regards,
Mo.

[mbaddah (Mo)]

Originally Posted by Starkler

For a newtonian I would definitely recommend a cheshire/sight tube combo tool over a laser. The Cheshire is everything you need to get it right whereas the same cannot be said for the laser.

The Orion Sight Tube/Cheshire seems to be a popular one, however would it be fine to shine a red light torch through it if Im to collimate at night? Cheers.

[mbaddah (Mo)]

Originally Posted by srv

I have ordered one today
so that I can setup my 10" GSO dob.
I also got a Cheshire: 1, because I want to learn to do it manually and 2, as a double check.

I'll let you know how it goes. Hopefully they get here before the weekend.

That would be very much appreciated thanks!

[erick (Eric)]

Originally Posted by mbaddah

The Orion Sight Tube/Cheshire seems to be a popular one, however would it be fine to shine a red light torch through it if Im to collimate at night? Cheers.

Yes, that is commonly done. Just shine your torch towards the reflecting surface where the daylight normally shines. You might find it's too bright if you shine it directly on the surface!

[srv]

Finally got mine in the mail, here's my 2cents worth:

I found that while it does what its designed to do, there are problems.
Due to the amount of 'slop' in the eyepiece it's difficult to get the laser in the exact alignment spot.

I laid the OTA (optical tube assy) on its own onto a flat surface, then inserted the laser so that it was in a vertical position to check alignment.
I found that when the eyepiece locking is tightened up the laser alignment changes. (Wondering if a 2" laser would be better than using a 1.25" adapter in the eyepiece ?)

I purchased the cheshire/sight tube as well , so I used that initially and then used the laser as a final check.

Strongly suggest looking at the Barlow method for laser alignment, which is what I am considering now.
On it's own a 1.25" laser it just isn't very reliable.
Possibly ok at night for a quick check, when you are checking the primary
but I wouldn't rely on it solely when doing the initial setup of both mirrors.

Matt.

(GSO 10" Dob.)

[erick (Eric)]

Yes, I reckon a 2" laser would be better. As far as I can see the 2" versions are much more "up-market" than the 1.25" - so anticipate better engineering?

However, add some packing to the 1.25" barrel of the laser to make it a more snug fit. I followed a suggestion of a layer of "contact" - yes the stuff we used to cover our school exercise books with (or still put in drawers and on shelves). That seems to be the right thickness. I always insert the 2"-->12.5" adapter into the focusser in the same orientation, regardless of what I am going to place it in - collimator or eyepiece. The laser always goes in with the same orientation (obviously, the viewing window towards the primary mirror end of the OTA).

To use the laser with barlow, I fit it to the barlow, check the spread out laser image is covering the centre mark of the primary, then I reach in front of the focusser with a piece of white paper in which I have punched a hole with a standard hole punch. When the beam from the laser passes through the hole, the reflection of the centre mark is seen on the white paper. In my 8" scope, the centre mark is a standard paper ring and the dark reflection nicely surrounds the hole I've punched in the paper. Wiggle the laser around to your heart's content and that reflection stays rock solid (unless you move the laser spot off the centre mark - then it vanishes (Yes, even with the contact, the laser does wobble in the two barlows I have, but given what the barlow does, it doesn't matter now.)

If you want to be more sophisticated, you could try this idea:-

http://www.iceinspace.com.au/index.p...63,406,0,0,1,0

Back to the unbarlowed laser. It is worthwhile watching the returned spot as you wind the focusser in and out and also as you move the tube in Alt. In both my scopes, the focusser movement has no effect, but from 0 deg to 90 deg elevation, the return laser moves maybe a mm or more. So, to be as precise as you can, you might wish to set the collimation with the OTA at the elevation you expect to be using that evening.

Edit: I should have said something that may be relevant. My habit is to loosen the three "locking screws" after putting the OTA in place, then collimating and leaving them loose. I only tighten them when I have finished the session and want to transport the OTA. One outcome is that the locking screws don't push the primary out of collimation on tightening. The converse is that if the mirror shifts a bit on the springs as the altitude changes, collimation may well change.

[mbaddah (Mo)]

Originally Posted by srv

Finally got mine in the mail, here's my 2cents worth:

I found that while it does what its designed to do, there are problems.
Due to the amount of 'slop' in the eyepiece it's difficult to get the laser in the exact alignment spot.

I laid the OTA (optical tube assy) on its own onto a flat surface, then inserted the laser so that it was in a vertical position to check alignment.
I found that when the eyepiece locking is tightened up the laser alignment changes. (Wondering if a 2" laser would be better than using a 1.25" adapter in the eyepiece ?)

I purchased the cheshire/sight tube as well , so I used that initially and then used the laser as a final check.

Strongly suggest looking at the Barlow method for laser alignment, which is what I am considering now.
On it's own a 1.25" laser it just isn't very reliable.
Possibly ok at night for a quick check, when you are checking the primary
but I wouldn't rely on it solely when doing the initial setup of both mirrors.

Matt.

(GSO 10" Dob.)

Very informative thanks for that. I have ordered a 2X televue barlow from overseas, hoping that won't take long to arrive as I'm planning on picking up 10" GSO tomorrow Cheers.