Jump to content


Photo

Who knows how to disassemble an Astro-Tech AT-111EDT Lens Cell?

equipment refractor optics
  • Please log in to reply
13 replies to this topic

#1 HBNorm

HBNorm

    Mariner 2

  • *****
  • Posts: 204
  • Joined: 24 Aug 2012
  • Loc: Huntington Beach, CA

Posted 19 August 2014 - 04:19 PM

Hi all,

 

I just received an Astro-Tech AT-111EDT that I purchased from Astromart for what I though was a smoking deal at $750 because of small spots on the coating of the primary elements.  To my horror, when I inspected the telescope upon receipt, it has the beginnings of fungus internally on the air-spaced triplet elements and the outside facing surface spots were likely due to fungus removal.  I live in So Cal so I doubt it'll spread due to the relatively dry climate and the fact that I store my scopes with desiccant, however, I want to remove it to minimize the potential for spreading and also cross-contamination with my imaging equipment (e.g., cameras, field flatteners, powermates, etc.).  I reached out to Astronomics via their website without response and the gentleman that answered the help line was of ZERO help as he recommended that I go back to the website.

 

I need to know two things:

 

1) Is there anyone or any company that services lens elements for telescopes.  Optimally, I'd like to send over the lens cell and have it dismantled, cleaned, and collimated (e.g., with Hydrogen Peroxide and Ammonia) to eradicate the fungus.  If not, 

 

2) Does anyone here have any insights into how to disassemble the lens cell holding the three air-spaced elements.  I was able to remove the lens cell from the OTA.  I just cant get any further as everything is too tight.  I need some pointers.  (i.e., is the primary locking ring locked in place with any type of thread locker?, how easy will it be to screw up collimation once the cell is disassembled?, Are threads reversed?, etc.)  It also looks like some of the smaller rings have been locked in place with a center punch to prevent disassembly. 

 

Any pointers would be greatly appreciated!

 

Thanks and clear skies!!!

 

Norm

 



#2 jrbarnett

jrbarnett

    Eyepiece Hooligan

  • *****
  • Posts: 20283
  • Joined: 28 Feb 2006
  • Loc: Petaluma, CA

Posted 19 August 2014 - 04:39 PM

Norm, I'd contact Astro-Tech first.

 

https://www.astronom...ntact-us_t.aspx

 

They are owned and operated by our host, Astronomics.

 

Good luck!

 

- Jim



#3 HBNorm

HBNorm

    Mariner 2

  • *****
  • Posts: 204
  • Joined: 24 Aug 2012
  • Loc: Huntington Beach, CA

Posted 19 August 2014 - 05:04 PM

Norm, I'd contact Astro-Tech first.

 

https://www.astronom...ntact-us_t.aspx

 

They are owned and operated by our host, Astronomics.

 

Good luck!

 

- Jim

Thanks Jim,

 

I tried that without luck.  No response on the web form.  And the gentleman that answered the phone directed me back to the web form.  That's why I'm reaching out to the expert community on CN!!!  ;-)

 

Norm 



#4 csrlice12

csrlice12

    Voyager 1

  • *****
  • Posts: 10806
  • Joined: 22 May 2012
  • Loc: Denver, CO

Posted 19 August 2014 - 06:43 PM

I'd try again....there are still some things best left to the experts, especially on expensive equipment.....



#5 HBNorm

HBNorm

    Mariner 2

  • *****
  • Posts: 204
  • Joined: 24 Aug 2012
  • Loc: Huntington Beach, CA

Posted 19 August 2014 - 09:58 PM

I'd try again....there are still some things best left to the experts, especially on expensive equipment.....

Will try again.  Hopefully they'll respond.  Not good customer service to go dark...



#6 orlyandico

orlyandico

    Fly Me to the Moon

  • *****
  • Posts: 5457
  • Joined: 10 Aug 2009
  • Loc: Singapore

Posted 19 August 2014 - 10:47 PM

You can do this trick.  I did it to remove radioactive yellowing on a camera lens but this will work as well for your purposes:

 

http://orlygoingthir...rium-glass.html

 

1) Buy a UV fluorescent bulb (used for money detectors) - do not get the incandescent!

 

2) stick it next to your lens (inside the dew shield) so that the UV light shines on the objective

 

3) Close the dew shield with some reflective material so that as much of the UV as possible goes into the objective

 

4) Leave it this way for a few days. A week even.  This is why you don't want to use the incandescent (used in bug zappers) - the incandescent UV bulb puts out too much heat and not much UV

 

The theory here is that the prolonged UV exposure will kill the fungus and any spores, thus arresting the growth. It won't get rid of any existing fungus but the reality is those fungus spots probably have zero to minimal effect on the image.  So the UV process is to prevent further spreading.



#7 sgorton99

sgorton99

    Gemini

  • *****
  • Posts: 3469
  • Joined: 30 Apr 2008
  • Loc: Wisconsin, Madison

Posted 20 August 2014 - 06:32 AM

I have had good luck with the Astronomy-Shoppe (Tony) and found him very responsive and helpful. I have sent 2 lenses to him for cleaning, with one needing new spacers. I also take my lenses out for the occasional Sun bath on nice days!

Attached Files



#8 ken svp120

ken svp120

    Surveyor 1

  • -----
  • Posts: 1902
  • Joined: 19 Dec 2004
  • Loc: Ohio

Posted 20 August 2014 - 08:48 AM

Norm,

 

I would not try working on this myself unless you are already knowledgeable with this sort of thing.  I think you are right to try contacting the vendor.  It is my understanding that Astro-Tech, our host, is concerned with good customer service.  I would get ahold of someone there and discuss what options you have.  If this is not covered by warranty then I wouldn't think they are under any obligation to make this right but they may be able to point you to someone who can.

 

Good Luck and keep us posted!



#9 KevH

KevH

    Ranger 4

  • *****
  • Posts: 334
  • Joined: 08 Mar 2010
  • Loc: Maine

Posted 20 August 2014 - 10:56 AM

I very recently called Astronomics about a discontinued AT product and they spent quite a bit of time with me on the phone.  I was impressed considering I was not the original owner.  They also indicated that they would be happy to take a look at my issue if I wanted to send it to them.  I agree with others... I'd try calling again.



#10 HBNorm

HBNorm

    Mariner 2

  • *****
  • Posts: 204
  • Joined: 24 Aug 2012
  • Loc: Huntington Beach, CA

Posted 20 August 2014 - 01:12 PM

Thanks all for the input.  I'm giving the objective cell daily sun bathes to arrest growth and kill any current growth and spores.  The amount of growth is minimal so I doubt there will be any degradation of image quality, and if there is a little, I'm sure flats will take care of that.  This wouldn't be covered by warranty so I'm happy to pay for the service.  Just want to get it cleaned as I'm a little OCD that way.. ;-)

 

Norm



#11 Astronomics

Astronomics

    Vendor: Astronomics

  • *****
  • Administrators
  • Posts: 4799
  • Joined: 07 Jun 2004
  • Loc: Right Here

Posted 20 August 2014 - 03:20 PM

I have checked the mailbox and don't see a question about the 111.  I am sure it is somewhere in cyberspace.  As far as taking apart the lens cell, there are a few ways to go about taking the glass out.  The hankey and drinking glass method is one.  We have some contacts as well for cleaning the optic.  Being a triplet lens system, I for one would not want to try doing it at home myself.  I am just not that adventurous.  



#12 Astronomics

Astronomics

    Vendor: Astronomics

  • *****
  • Administrators
  • Posts: 4799
  • Joined: 07 Jun 2004
  • Loc: Right Here

Posted 20 August 2014 - 03:49 PM

This is the local gent we have sent people to in the past.  http://www.suddartho...m/Services.html



#13 HBNorm

HBNorm

    Mariner 2

  • *****
  • Posts: 204
  • Joined: 24 Aug 2012
  • Loc: Huntington Beach, CA

Posted 20 August 2014 - 07:35 PM

Michael,

 

Thanks for commenting on my post.  I reached out to Suddarth Optics and Cory came back with a great quote.  Really appreciate your guidance.  I'll leave it to a pro so I don't screw up collimation.  I'm a big fan of your Astro-Tech line so I'm looking forward to using the 111EDT once it's cleaned up.  It was a used scope that came from Puerto Rico so the high humidity climate obviously got to it.  Fortunately the fungus is reversable at this point.

 

Norm



#14 Geo.

Geo.

    Mercury-Atlas

  • *****
  • Posts: 2843
  • Joined: 01 Oct 2008
  • Loc: Upstate NY

Posted 22 August 2014 - 12:33 PM

Dealing with collimation is not a biggy provided the adjusting screws are not glued so tightly that they can be used. I've got a triplet here I thought I'd have to collimate, fortunately the focuser is out of collimation.

 

What would scare me possible damage while disassembling the cell. And then there's, what? 15 parts and maybe 200 ways to assemble it incorrectly.







Also tagged with one or more of these keywords: equipment, refractor, optics



Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics