126 replies to this topic

[AdmiralAckbar]

I just bought the OP's scope that's described in this thread  Thanks, Bob!

 

I'm posting to ask those who are experienced with the Comet Catcher: What should one expect in terms of cooldown time? Short? Long? Any tips/tricks? This is (almost) the first scope I've owned with a corrector plate, so advice will be appreciated.

 

Warm wishes,

AA

Edited by AdmiralAckbar, 07 September 2020 - 07:35 PM.

[beacon222a]

Celestron Comet Catcher telescope part needed , can anyone help please : )

 

 

Anyone know how I can connect this celestron porro prism to my celestron telescope ? what can I use and where can I get a part ? the openings are 2 different sizes and I need some type of reducer or coupler ???? any help is appreciated : )

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Edited by beacon222a, 17 January 2021 - 03:20 PM.

[Jeff C]

CC Users,

 

I picked up the Svbony SV161 Helical focuser for my black tube Comet Catcher and unfortunately it doesn't fit. The male threads closest to the knurled end are to small.  The specs say they are M31*.05 male threads.  I believe the threads on the focuser sled are approximately 36.4 mm female.  So far no luck finding and adapter that will work.  Can anyone suggest and adapter that will or did I order the wrong focuser? 

[Soundboy121]

Search for Baader Microfocuser ,36.4mm
I think B and H or Adorama has em for like 40$

[laixiaolue]

You can buy this https://www.ebay.com...:Bk9SR6Dk18T6YA

 

 

 

Celestron Comet Catcher telescope part needed , can anyone help please : )

 

 

Anyone know how I can connect this celestron porro prism to my celestron telescope ? what can I use and where can I get a part ? the openings are 2 different sizes and I need some type of reducer or coupler ???? any help is appreciated : )

 

[Jeff C]

The Ebay unit looks exactly like the Svbony and unfortunately won't work.  The Baader unit looks like a winner so ordering one today.  

 

Thanks for the replies.

[laixiaolue]

Are you sure? I have this SvBony on my comet catcher.

 

 

 

 

 

 

The Ebay unit looks exactly like the Svbony and unfortunately won't work.  The Baader unit looks like a winner so ordering one today.  

 

Thanks for the replies.

 

 

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[Jeff C]

Pretty sure. I compared the specs with Svbony's website and they are the same. The tube side thread size isn't listed on the ebay listing but everything else appears to be the same. Is yours model: SV161? The thread diameter is around 32mm which is too small. Mine is the black tube model so it's possible there's a difference. 

[laixiaolue]

I don't know the model. I bought 5 on eBay last time when they had a sale. I sold 4 here as the upgrade for comet catcher. The thread is 36.5mm, the standard Vixen thread.

[Soundboy121]

@ Jeff C if u use the Baader microfocuser u will need one of the C C extension tubes to reach focus

[Soundboy121]

This 

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[Marco Prunotto]

I would like to use the comet catcher for remote electronic assisted astronomy. Can someone of you suggesting me a solution to adopt a remote focuser to this scope?

 

Any suggestion?

[jgraham]

Hmmm, I set the focus on mine as part of the setup and then move inside. With the helical focuser mod it's easy to set and holds the focus well.

Food for thought.

[Soundboy121]

I agree with JGraham…. I do recall a picture somewhere here , where someone rigged a 9volt battery powered Focuser with the squiggly telephone cord to their C C ..

[telesonic]

Marco,

 

John is right, with the helical mod - you should be good to set and forget.

 

But in the spirit of discussion, yes, it probably is possible with the original sled focuser.

 

It will require some fabrication / ingenuity to make it work. I remember seeing a post on here, where a user adapted an older Celestron / JMI Motofocus unit (from a C8 SCT) on to his Comet Catcher. It wasn't very detailed about how he made it work, since that wasn't the main thread. I can dig around and see if can be located in the archives here, and if so - I'll edit in a link.

 

Now, that is something that I have also been slowly working on, for one of my Comet Catchers. I already had the JMI Motofocus unit from my Celestron C8, and I also had a few spare adapters (for the knob attachment) and other parts.

 

This is only been something I have tested a few times, so it is not a proven setup. You will also need to make a bracket to mount the Focus Motor to the tube, aligned with the focus knob on the scope - I made a simple bracket out of thin aluminum that worked, but I scrapped it. Something better could be made.

 

 

Here is a picture of how I adapted the Motofocus bushing/adapter to the Comet Catcher knob:

 

 

I used a section of PVC (grey) electrical Conduit, sized to fit over the Motofocus adapter (which is plastic) and epoxied the two of them together. The Larger PVC fits over the Comet Catcher Focus Knob, and is secured with three small allen/hex set screws. This required drilling and threading the grey section for the set screws. This adapter doesn't interfere with operation of the focuser, and just barely clears the Sled assembly. It was kind of a prototype thing with parts I had, and surprisingly it worked pretty well.

 

The motofocus I used was an older vintage unit - that hasn't been sold in years. It has a mini jack (1/8" headphone style plug.) and for testing, I used a Rigel Systems NFocus designed for those older steppers. It wasn't wireless, but it worked. I imagine with some work, a wireless version could be made or adapted to work.

 

I haven't had the motor on that scope finished yet, since I was working on fixing other problems with the tube itself (repairing holes - it's a topic on here) and dealing with other issues. I hope to fabricate a better bracket this winter (perhaps removable) so the motor can be added/ removed more easily.

 

 

So yes, doable - wired. Wireless? possibly.

 

Cheers,

Temp

 

[telesonic]

I agree with JGraham…. I do recall a picture somewhere here , where someone rigged a 9volt battery powered Focuser with the squiggly telephone cord to their C C ..

 

That was probably the post I was referring to above. I'll need to dig around and see if I can locate it.

 

These are such oddball scopes (also fun!) that I have 2. One fixed and repainted, one at the machinist. It would be nice if there was a repository of useful posts/threads/articles on these, even just as bookmarks or links.

 

Cheers,

Temp

[Marco Prunotto]

Thank you all.

Uhmm… I’m not even able to use well the hammer…not sure I dan do all what you did.

Not my cup of team. I will keep the CometCatcher for visual…

 

Best regards,

Marco

[CrossoverManiac]

Two questions:

 

1. How much does the Comet Catcher weighs?
2. How difficult is it to collimate?

[telesonic]

 

Two questions:

 

1. How much does the Comet Catcher weighs?
2. How difficult is it to collimate?

 

 

1. I'm not sure, as I've never weighed mine. I'd estimate around 6 pounds without tube rings & dovetail bar.

2. It's not too bad...... but.... there are some things to be aware of.

 

 

There is always a BUT....

It's technically a fast newtonian, but with a Schmidt Corrector plate (yes, the front plate is not a flat piece of glass) so that makes it... interesting.

 

If all you need to align / collimate is the primary, it's easy. If the secondary mirror is out of whack, then you need to remove the corrector.

Before you do that, it's best to mark the corrector and front cell with tape - and along with a corresponding mark on the tube - so that it all goes back together.... correctly.

 

Then you can adjust the secondary mirror. Despite being a F/3.6 scope, it's pretty easy. I have my own way of doing that, for these scopes, but I use multiple tools for this.

 

A modified 1.25" laser collimator, Astrosystems Light-pipe, an old Orion crosshair tool, CatsEye reflective cheshire tool and a 1.25" AstroSystems Autocollimator. You don't need all of these tools, but they help. I already had most of them before I got the Comet Catcher.

 

I'd advise adding a reflective center-spot to your primary mirror though. CatsEye products are the best bang for the buck here.

 

Cheers,

Temp

[davidmcgo]

I have an early orange one with an oddball secondary holder with a single round stalk and a holder machined from plate stock that is a nightmare.  Must have been from before they had the cast assembly.  The secondary is epoxied somewhat offset laterally and if I collimated with the tools, whenever I look at a star it is badly flared to one side.  If I then collimated with the primary I am tilted enough to cut off one side of the aperture.  The sled focuser also has a sideways tilt that adds to it.

 

So collimation can be maddening.  You can’t adjust the secondary with the corrector on so it is a lot of trial and error and frustration.  But when it is zeroed in by using a star and racking through focus it will split the Epsilon Lyra and show Cassini’s Division.  Just with a somewhat tilted focal plane.  I also found it is really tough on eyepieces, my 16t5 Nagler isn’t great with it at all.  Most satisfying are an old Celestron Silvertop 26mm, 10mm, and the matching 2x Barlow.  The Barlow is handy since it is parfocal with the eyepieces so the helical focuser hack lets me keep the sled locked in place since it creeps on its own and is hard to nail focus.

 

Dave

 

 

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[davidmcgo]

It is a really nice looking scope, pretty much mint when I got it.

 

Dave

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[davidmcgo]

Mine only came with the camera adapter.  The Svbony helical focuser fits, but doesn’t allow the Barlow to seat fully.  I recently switched to this item on a short 10mm M42 extension and the camera adapter and it works great

 

https://www.svbony.c...0-75-reflector/
 

It came without any grease on the threads, mainly meant to lock focus for a little guidescope but with a dab of Superlube it makes a nice helical and has a wide enough opening the Barlow can be inserted fully and still focus.

 

Dave

Edited by davidmcgo, 16 December 2023 - 11:39 AM.

[Soundboy121]

This was last summer  CC with a ZWO 183 MC …. 
*photo file size was reduced to be able to load …

I like it for EAA and Visual. 
 

So I have two …. One has a single screw for stalk the other has 2 

 

I haven’t got around to doing, but been wanting to insulate , dew heat both ends and a proper dew shield for them  

 

it’s a back heavy OTA so I think Rings and a longer vixen are needed.  
 

I took off the tripod thingie on both and covers holes 

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Edited by Soundboy121, 16 December 2023 - 11:51 AM.

[Soundboy121]

@telesonic  can u post picture of yours   the repainted one?  any advice on how to repaint an OTA ?

[Soundboy121]

I caught the Green Comet in February with my CC 

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