I need a collimating tool!

[Greg6498]

I need a a really accurate,easy to use collimating tool. I have a used laser collimator but it does not fit snugly in the focuser so I feel it’s not very accurate. The idea of collimating causes me some anxiety anyway, so accurate and easy is the key! Can any of you offer any suggestions to help me out?

[JOC]

Have you downloaded and followed literally the letter Astrobabys collimation guide?  She uses a Cheshire collimator and I did absolutely everything that was suggested, regardless of how odd it sounded and I got a perfectly collimated telescope.  I was having kittens at the thought of doing the job before I read hhe guide..  I have seen it written that a symmetrical turn of insulating tape can make the fit of collimators a bit tighter.

[wimvb]

I only use a simple drainage pipe end cap with a hole in it as a collimation cap, plus a barlowed laser. With the cap, I center the secondary. Then I use the barlowed laser to align the primary. With the barlowed laser, laser collimation is less critical. So far, this has worked for me.

http://www.micosmos.com/enlaces/collimation_with_a_Barlowed_Laser.pdf

[Major]

Cheshire for me as well. Simple yet effective.

[Swoop1]

I have a Cheshire and it does the job perfectly.

[Scooot]

https://www.firstlightoptics.com/howie-glatter-collimation-tools/howie-glatter-single-beam-2-inch-laser.html

https://optcorp.com/products/starlight-instruments-laser-collimator

These are excellent 

[Sunshine]

NOOOOOOOOOOO!!! you've discovered collimating!! OH NO please don't fall into the giant dark hole collimation creates, from which theres no escaping. I have been there and it sucks the fun out of the hobby, collimate but don't seek perfection because it doesn't exist and DONT TOUCH THE SECONDARYYYYYY!!!!!!. Warning aside, its not hard, but can be if you get carried away, if the views blow you away then don't touch it, i speak from experience as a former collimation junkie.

[Charic]

Cheshire Tool.

I've found this to be the most accurate tool.

I also use a Barlowed laser, or the most basic 35mm film cap, and/ or dust cap. They all work.

These tools don't actually 'tool' anything, they just  help align the eye to the scopes axis.

You could potentially align every thing by sight alone then Star test to check  accuracy. 

Once your confident with collimation on your own scope, you'll wonder what all the fuss was about ?

[John]

1 hour ago, Greg6498 said:

I need a a really accurate,easy to use collimating tool. I have a used laser collimator but it does not fit snugly in the focuser so I feel it’s not very accurate. The idea of collimating causes me some anxiety anyway, so accurate and easy is the key! Can any of you offer any suggestions to help me out?

How do your star tests look ?

If they are decent then I don't think you have a problem. Astro Baby's guide shows you how to do this.

I'm another user of the simple cheshire collimator with my 12 inch dobsonian.

 

[cletrac1922]

I use laser collimator to collimate my dob

If you only using your scope, home situation, very rarely need to touch your collimation

I am out couple of times per month with my club, doing presentations in primary schools, scout/guide groups, and still rarely need to re-collimate

Have found that my Saxon laser collimator, is also not a snug fit, and just put a bit of electrical tape around it to stop the wobble

John

 

 

[Geoff Barnes]

I use a basic Cheshire only very occasionally to check the secondary mirror alignment, but I've never used anything for the primary alignment since I  discovered Gary Seronik's Tool Free method, which is basically just a star alignment.

https://garyseronik.com/no-tools-telescope-collimation/

It takes a matter of a couple of minutes to adjust the out of focus star image to the centre of view and away I go, nice sharp images  and so easy!

[Greg6498]

54 minutes ago, John said:

How do your star tests look ?

If they are decent then I don't think you have a problem. Astro Baby's guide shows you how to do this.

I'm another user of the simple cheshire collimator with my 12 inch dobsonian.

 

Star test looks pretty good! I want a good collimator for when the need arises.

[Scooot]

I also have a Cheshire, which works well, but I havent used it for years.

Most of the time the collimation just needs tweaking, so a good laser is perfect, which is why I bought the Howie Glatter. I had similar problems to you with the one I  had before.

The Howie sits snugly in the Focuser, with no movement of the beam if you rotate it. It’s a precision instrument and very well made, but pricey.

 

[jetstream]

For a tube dob there is no question: https://catseyecollimation.com/

I also use Glatters laser and Tublug for my truss dob, very very easy to use:https://starlightinstruments.com/store/index.php?route=product/product&product_id=157

You still need a sight tube with Glatters equipment to "center" the sec under the focuser.

BTW, there is no need ignore the secondary out of concerns, its all very easy.

[Alan64]

There's nothing like receiving a package from the UK, like that time I had sent a sample of questionable tea to Twinings, its having been packed here in the States, whereupon they discovered that it had indeed been adulterated.  They then, much to my surprise, sent me a box of several different flavoured teas of theirs that were absolutely wonderful, whilst they lasted.  I don't think I'll ever receive anything that nice again...

https://www.firstlightoptics.com/other-collimation-tools/premium-cheshire-collimating-eyepiece.html

That's the best Cheshire in the world, at present, although not due to its anodised colour; but that does make it a bit special nonetheless.  You won't misplace it.

If you want to give another one of these a try, there's something you should know about them...

They're improved now, and with a triplet-lens, for a tighter dot...

https://www.ebay.com/itm/1-25-SVBONY-7-Bright-Level-Next-Generation-Laser-Collimator-for-Astro-Telescope/263812604382?hash=item3d6c74e1de:g:zHsAAOSw3vFbWh6T:rk:2:pf:0

But, as with all entry-level laser-collimators, it will most likely require collimation, and before it's used to collimate the telescope...

https://www.youtube.com/watch?v=5ZsgNlgIrqQ

When you have trouble with slop, with a telescope's visual-back, you shim it.  For example, I have this focusser, but it's not a 1.25", a 1.26" instead...

That's a shim of .005"-thick PVC...

https://www.ebay.com/itm/Midwest-Products-70406-Blue-PVC-Sheets-005-x-7-6-x-11-4-sheets-/183636053625?_trksid=p2385738.m4383.l4275.c10#shpCntId#shId

https://www.hobbylobby.com/Crafts-Hobbies/Hobbies-Collecting/Tools-Blades/Brass-Sheet---0.005"/p/21620

You get the idea.  If in a pinch, a layer or two of clear packing tape will serve.  However, you may need a shim that's thicker, I do not know.  In that event, and if you don't have one already, get one of these calipers.  I have one myself, and I wouldn't be without it when working with my telescopes...

https://www.harborfreight.com/6-in-digital-caliper-61585.html

That would enable you to determine the exact deviation from the norm, then to shim accordingly.

 

[bottletopburly]

FLO sell a collimation cap for about a fiver , and I find a 1.25  compression adapter works good for holding laser snug just turn to hold snug but so you can spin it , so turn it so laser creates a circle around primary ring that way if laser is out it doesn’t matter .

[Moonshane]

I use a Cheshire too. Unlike a laser (unless you make various additional templates) you can perform all aspects of collimation with it.

As good as the astro baby site is, I did what I consider to be a simpler but still effective guide as follows. As above, you are better getting out observing with a view that's not quite perfect than sat in your dining room fiddling and frustrated. With a guide and experience you'll learn to know when to collimate if be so quick at the important but (primary) you'll have a quick check and tweak (10 seconds) every time. Other factors, eg seeing and transparency, will have greater effects in the view than a slightly miscollimated scope.

 

[JOC]

http://www.astro-baby.com/astrobaby/help/collimation-guide-newtonian-reflector/

This^^^ is Astro Baby's guide

FWIW I bought a laser as it seemed to sound like a good idea.  Like you I was unimpressed with it and bought a Cheshire and followed Astro Baby's guide and didn't look back.

 

 

[billyharris72]

1 hour ago, bottletopburly said:

FLO sell a collimation cap for about a fiver 

I'd second this option. It's as easy as it gets and for f5 or slower it's all you need, especially for visual.

If you need to collimate the secondary (e.g. if you've had the scope apart for some reason) then I'd go for  Cheshire. The laser is handy for the initial rough alignment, but the Cheshire (or sight tube) is the best tool for finishing.

Bear in mind that with visual use of slower scopes the secondary has to be pretty bad to affect what you'll see in the eyepiece though. 90% of the time a collimation cap is plenty.

Billy.

[kev100]

I too recommend the collimating cap. Sometimes us a laser just as a double check/fine tuner, but mostly it's just the cap: https://www.firstlightoptics.com/other-collimation-tools/rigel-aline-collimation-cap.html

[Alan64]

Agena Astro, in California, offers a collimation-cap, and with every item they sell with free shipping...

https://agenaastro.com/rigel-systems-aline-telescope-alignment-eyepiece.html

The collapsible's tube would need to be sealed, with a shroud I imagine, then a white cloth or other over the opening at the front.  Then, a lamp in front of that to illuminate the telescope's interior...

It is then that the entire optical system can be seen, although I use a small camera to zoom in and snap a shot.  It's all there within this image, and with the collimation thrown out slightly to illustrate and describe...

1. The hole in the center of the cap, and through which the image was taken with a camera

2. The center-spot of the primary-mirror

3. The reflective underside of the cap

4. The silhouette, or shadow, of the secondary-mirror

5. The secondary-assembly's spider-vanes; nasty things those are.

6. The reflective surface of the primary-mirror; all of the white area in fact

7. The primary-mirror's clips; all three, or however many, should be visible, and evenly.

8. The interior of the drawtube

[Greg6498]

16 hours ago, Alan64 said:

There's nothing like receiving a package from the UK, like that time I had sent a sample of questionable tea to Twinings, its having been packed here in the States, whereupon they discovered that it had indeed been adulterated.  They then, much to my surprise, sent me a box of several different flavoured teas of theirs that were absolutely wonderful, whilst they lasted.  I don't think I'll ever receive anything that nice again...

https://www.firstlightoptics.com/other-collimation-tools/premium-cheshire-collimating-eyepiece.html

That's the best Cheshire in the world, at present, although not due to its anodised colour; but that does make it a bit special nonetheless.  You won't misplace it.

If you want to give another one of these a try, there's something you should know about them...

They're improved now, and with a triplet-lens, for a tighter dot...

https://www.ebay.com/itm/1-25-SVBONY-7-Bright-Level-Next-Generation-Laser-Collimator-for-Astro-Telescope/263812604382?hash=item3d6c74e1de:g:zHsAAOSw3vFbWh6T:rk:2:pf:0

But, as with all entry-level laser-collimators, it will most likely require collimation, and before it's used to collimate the telescope...

https://www.youtube.com/watch?v=5ZsgNlgIrqQ

When you have trouble with slop, with a telescope's visual-back, you shim it.  For example, I have this focusser, but it's not a 1.25", a 1.26" instead...

That's a shim of .005"-thick PVC...

https://www.ebay.com/itm/Midwest-Products-70406-Blue-PVC-Sheets-005-x-7-6-x-11-4-sheets-/183636053625?_trksid=p2385738.m4383.l4275.c10#shpCntId#shId

https://www.hobbylobby.com/Crafts-Hobbies/Hobbies-Collecting/Tools-Blades/Brass-Sheet---0.005"/p/21620

You get the idea.  If in a pinch, a layer or two of clear packing tape will serve.  However, you may need a shim that's thicker, I do not know.  In that event, and if you don't have one already, get one of these calipers.  I have one myself, and I wouldn't be without it when working with my telescopes...

https://www.harborfreight.com/6-in-digital-caliper-61585.html

That would enable you to determine the exact deviation from the norm, then to shim accordingly.

 

Hi Alan! I really like the collimating Cheshire eyepiece from first light optics that you recommended, but how do you use it?

Greg

[laser_jock99]

22 hours ago, Scooot said:

https://www.firstlightoptics.com/howie-glatter-collimation-tools/howie-glatter-single-beam-2-inch-laser.html

These are excellent 

Agreed. I collimate my uber critical F2.9 Newtonian astrographs (yes F2.9!!) with a Howie-Glatter. Nothing else comes close.....

[Alan64]

3 hours ago, Greg6498 said:

Hi Alan! I really like the collimating Cheshire eyepiece from first light optics that you recommended, but how do you use it?

Greg

You had asked the same within a PM.  I've replied to you there.  

[Seanelly]

18 hours ago, billyharris72 said:

I'd second this option. It's as easy as it gets and for f5 or slower it's all you need, especially for visual.

If you need to collimate the secondary (e.g. if you've had the scope apart for some reason) then I'd go for  Cheshire. The laser is handy for the initial rough alignment, but the Cheshire (or sight tube) is the best tool for finishing.

Bear in mind that with visual use of slower scopes the secondary has to be pretty bad to affect what you'll see in the eyepiece though. 90% of the time a collimation cap is plenty.

Billy.

I agree entirely with your observations.