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CATSEYE Collimation question about replacing center sticker

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#1 biptunia

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Posted 04 March 2024 - 11:14 PM

Anyone here done this? I'm not that nervous to take out my primary and clean it, never done it, but it looks straightforward in videos.

 

But to use the CATSEYE Collimation system you have to remove the center collimation sticker that comes on the primary and replace it with the radiation warning-shape sticker that comes with the CatsEye. How do you do that? Alcohol and razor blades?

 

Any tips?

 

Using Quattro 250P Imaging Newtonian 10" but would probably be same for anything.

 

Thank you.

MWD



#2 CrazyPanda

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Posted 05 March 2024 - 12:18 AM

I'd follow Mike Lockwood's recommendation:

 

https://www.cloudyni...rror/?p=9010112

 

Pour a bit of rubbing alcohol in the center - enough to soak the center spot, and then pick at it with your fingernail once the adhesive has weakened. Damage to the very center of the mirror is not a big deal as it will be in the shadow of the secondary.


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#3 ram812

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Posted 05 March 2024 - 12:29 AM

Like CrazyPanda says, and dear gosh, DON'T use a razor blade or other sharp instrument😯! You can use a finger nail, though. I haven't seen many metal ones lately!😁 Good luck

Clear Skies! RAM
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#4 biptunia

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Posted 05 March 2024 - 12:32 AM

Like CrazyPanda says, and dear gosh, DON'T use a razor blade or other sharp instrument! You can use a finger nail, though. I haven't seen many metal ones lately! Good luck

Clear Skies! RAM

Thank you.

I like the info on the other thread too of saying to do it AFTER cleaning. (I'm assuming so you don't accidentally move around gritty dust that might be on the mirror). I would have instinctively done it before cleaning, but now I know.

 

Thanks all.
 


Edited by biptunia, 05 March 2024 - 12:40 AM.

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#5 Vic Menard

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Posted 05 March 2024 - 08:20 AM

Anyone here done this? I'm not that nervous to take out my primary and clean it, never done it, but it looks straightforward in videos.

 

...Any tips?

To answer your first question, "Many times."

A couple of questions for you:

How old is your Quattro 250P?

How far off-center is your current center marker?


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#6 biptunia

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Posted 05 March 2024 - 08:23 AM

To answer your first question, "Many times."

A couple of questions for you:

How old is your Quattro 250P?

How far off-center is your current center marker?

Scope is brand new. I've used it once. I did a rough collimation with a laser that seems in when put in a V block. Then I shot this,

https://www.astrobin.com/ce07w2/

 

so I think it's centered, but won't know until I take it out and measure it, I suppose.

I didn't get my CatsEye system yet, just ordered it.

 

Thank you.
 



#7 Vic Menard

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Posted 05 March 2024 - 08:38 AM

With a brand new scope I would be cautious of a possible brand-new mirror.

 

Generally speaking, I try to avoid cleaning mirrors or removing center markers (assuming they're removable) for the first several months. This allows the mirror surface to harden as oxygen reacts with the mirror surface (this seems to vary from one coater to another, but I still feel it's worth considering.

 

If you find that your current center marker is well-centered (less than ~0.5mm), you can place the HotSpot on top of the current marker.


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#8 biptunia

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Posted 05 March 2024 - 08:43 AM

With a brand new scope I would be cautious of a possible brand-new mirror.

 

Generally speaking, I try to avoid cleaning mirrors or removing center markers (assuming they're removable) for the first several months. This allows the mirror surface to harden as oxygen reacts with the mirror surface (this seems to vary from one coater to another, but I still feel it's worth considering.

 

If you find that your current center marker is well-centered (less than ~0.5mm), you can place the HotSpot on top of the current marker.

You make very good points there. So how long would you wait before removing it? 3 months good?

Will it hurt to wash it right away if I follow the common videos on how to to it?

 

Will that CatsEye completely cover the other one? I think if there's some sticking out under the edges it will confuse the reading of the 3 different reflections you see with that system.


Edited by biptunia, 05 March 2024 - 08:45 AM.


#9 CrazyPanda

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Posted 05 March 2024 - 09:00 AM

You make very good points there. So how long would you wait before removing it? 3 months good?

Will it hurt to wash it right away if I follow the common videos on how to to it?

 

Will that CatsEye completely cover the other one? I think if there's some sticking out under the edges it will confuse the reading of the 3 different reflections you see with that system.

Generally you should wait about 6 months or so on a brand new coating. That said, who knows how long the mirror in your scope has been around. The whole scope could have been sitting in a warehouse for a couple of years.

 

You should definitely remove the old center spot. The whole advantage of the Cats Eye hotspot in an F/4 astrograph like yours is to use it with an autocollimator, which will be much easier to get good readings on if the only center spot visible is the hotspot.


Edited by CrazyPanda, 05 March 2024 - 09:02 AM.

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#10 biptunia

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Posted 05 March 2024 - 09:14 AM

Generally you should wait about 6 months or so on a brand new coating. That said, who knows how long the mirror in your scope has been around. The whole scope could have been sitting in a warehouse for a couple of years.

Should wait that long to wash it, or put remove the old sticker / put on the new sticker?

 

I'll write the retailer and see if they know how long they had it.



#11 CrazyPanda

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Posted 05 March 2024 - 09:17 AM

Should wait that long to wash it, or put remove the old sticker / put on the new sticker?


Both.

EDIT: weird it only posted your quote.

Edited by CrazyPanda, 05 March 2024 - 09:19 AM.

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#12 biptunia

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Posted 05 March 2024 - 09:19 AM

 

Should wait that long to wash it, or put remove the old sticker / put on the new sticker?

 

Confused by the question mark still there. Are you saying you'd wait 6 months after manufacture to wash it AND to do the stickers, is that correct?



#13 CrazyPanda

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Posted 05 March 2024 - 09:20 AM

Sorry, that was really weird. I replied "both" after your quote and then it only posted the quote and stripped off the "both". I've noticed that CloudyNight's BBCode parser has been struggling as of late...

I edited my reply.

Edited by CrazyPanda, 05 March 2024 - 09:21 AM.

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#14 biptunia

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Posted 05 March 2024 - 09:23 AM

Sorry, that was really weird. I replied "both" after your quote and then it only posted the quote and stripped off the "both". I've noticed that CloudyNight's BBCode parser has been struggling as of late...

I edited my reply.
 

Computers are an interesting mix of science and voodoo. lol.

Thank you for clarifying. Writing the retailer now.


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#15 Vic Menard

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Posted 05 March 2024 - 10:32 AM

1.) So how long would you wait before removing it? 3 months good?

2.) Will it hurt to wash it right away if I follow the common videos on how to to it?

 

3.) Will that CatsEye completely cover the other one? I think if there's some sticking out under the edges it will confuse the reading of the 3 different reflections you see with that system.

1.) Three months if the center marker adhesive releases easily--six months if it doesn't release easily.

 

2.) No-force washing to remove dust/pollen/condensates is OK with a new coating and should be done soon after the exposure if you want the contaminants to release easily. Organics like tree sap or insect residues should be removed as soon as possible with extra care as they can sometimes remove the underlying coating if you try to force them to release. I suggest that you don't submerge the mirror in water when cleaning the surface. Running water over the surface while cleaning effectively moves contaminants off and away from the mirror surface. A 10-inch mirror should easily fit in a kitchen sink with a towel under the mirror to keep the mirror supported and the surface tilted about 10- to 20-degrees. And remember to move the faucet away from the mirror when you lift the mirror from the sink! 

 

3.) The Catseye HotSpot is larger than most common notebook paper reinforcement ring "donut" center markers. The HotSpot's critical alignment features are the radial gaps and the outermost edge. The inner 1/4-inch hole allows outgoing thin beam laser alignment (focuser axis) and Barlowed return beam laser alignment (primary mirror axis).

 

You can see how the HotSpot works here:  https://www.cloudyni...ents/?p=3262426   (Note the remnant offset etched donut visible in the 1/4-inch perforation:  https://www.cloudyni...ents/?p=3262966  )


Edited by Vic Menard, 05 March 2024 - 10:43 AM.

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#16 Jason D

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Posted 05 March 2024 - 11:02 PM

  (Note the remnant offset etched donut visible in the 1/4-inch perforation:  https://www.cloudyni...ents/?p=3262966  )

grin.gif

Jason


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#17 biptunia

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Posted 11 March 2024 - 04:54 PM

With a brand new scope I would be cautious of a possible brand-new mirror.

 

Generally speaking, I try to avoid cleaning mirrors or removing center markers (assuming they're removable) for the first several months. This allows the mirror surface to harden as oxygen reacts with the mirror surface (this seems to vary from one coater to another, but I still feel it's worth considering.

 

I was really nervous about cleaning the mirror on my new 10" Quattro Newt after this comment, so I called the manufacturer, Sky-Watcher.

I talked to Alex there who said this is NOT an issue with their Newts.

He said their mirrors are hardened before installation in the scope, and you can safely clean the mirror on a brand new Sky-Watcher Newt as long as you use normal precautions. 

He recommended this Sky-Watcher "What's Up" series video for mirror cleaning instructions.

Mirror part starts at 32:30 
https://www.youtube....Cr0ghpr8IYSppyU


Edited by biptunia, 11 March 2024 - 04:58 PM.


#18 RoofMonkey911

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Posted 12 March 2024 - 07:03 AM

40:18 point of the video… ‘What this does is just scrubs off any particles’

OUCH

Also drags any of those particles across the surface

 

I was really nervous about cleaning the mirror on my new 10" Quattro Newt after this comment, so I called the manufacturer, Sky-Watcher.

I talked to Alex there who said this is NOT an issue with their Newts.

He said their mirrors are hardened before installation in the scope, and you can safely clean the mirror on a brand new Sky-Watcher Newt as long as you use normal precautions. 

He recommended this Sky-Watcher "What's Up" series video for mirror cleaning instructions.

Mirror part starts at 32:30 
https://www.youtube....Cr0ghpr8IYSppyU


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#19 biptunia

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Posted 12 March 2024 - 04:02 PM

40:18 point of the video… ‘What this does is just scrubs off any particles’

OUCH

Also drags any of those particles across the surface

Do you do it without cotton balls? My buddy juse uses fingers.

 

One thing they don't do here that a lot of videos do is blow the dry mirror off first with a bulb. That seems to make sense.
 


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#20 RoofMonkey911

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Posted 12 March 2024 - 11:15 PM

The wording chosen just sounded horrible to me.  There is a huge ongoing debate on fingertips VS cotton.

I also prefer to use my fingertips.

Another thing that bugs me with that video is just using 1 cotton ball. Let’s say it does catch an abrasive speck of something… you’ll just continue to “scrub” it around. If using cotton balls….. 1 pass, rotate it for the second pass then toss it and grab another cotton ball.

 

 

Do you do it without cotton balls? My buddy juse uses fingers.

 

One thing they don't do here that a lot of videos do is blow the dry mirror off first with a bulb. That seems to make sense.
 


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