Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

CPC 1100

SCT optics
  • Please log in to reply
6 replies to this topic

#1 Oops!

Oops!

    Lift Off

  • -----
  • topic starter
  • Posts: 3
  • Joined: 20 May 2019
  • Loc: Idaho

Posted 20 May 2019 - 08:40 PM

Hello!

long time reader first time posting.  If this topic is somewhere else I apologize for posting this question in the wrong place.

 

I recently purchased a CPC 1100 and was attempting to install a camera mount on the tube.  I unscrewed the wrong screw and a nut fell off inside. So In my haste and knowing better, I removed the corrector plate retainer, and before I marked shim or plate positions I foolishly took it off.  The cork shims fell out and now I have no way to align the plate.  There is a permanent marker line on the plate but no matching mark on the tube.  So both alignments will be incorrect.  

 

If there is a procedure to rectify my problem I would appreciate hearing about it!

 

Thanks!

Dave



#2 Neptune

Neptune

    Apollo

  • *****
  • Posts: 1032
  • Joined: 16 Apr 2007
  • Loc: Georgia

Posted 20 May 2019 - 08:47 PM

The only way to remedy the problem that I am aware of is to replace the plate and the cork shim's (evenly spaces around the outer perimeter of the plate), observer with the scope and see what the diffraction pattern looks like. if it looks less than stellar, rotate the plate ever so slightly and look again, until the star looks good. This could take some time by yourself, maybe get a helper to turn the plate ever so slowly while you look at the star image.


  • Augustus and Oops! like this

#3 ShaulaB

ShaulaB

    Apollo

  • *****
  • Posts: 1389
  • Joined: 11 Oct 2012
  • Loc: Missouri

Posted 20 May 2019 - 09:49 PM

Probably the most expensive solution would be to send it back to Celestron. If the loose nut damaged the coating on the primary mirror, or secondary, they might get them re-coated for you. None of this will be cheap. So sorry about your mishap. C#@p happens.


  • Oops! likes this

#4 Dynan

Dynan

    Mercury-Atlas

  • *****
  • Posts: 2537
  • Joined: 11 Mar 2018
  • Loc: NOLA

Posted 20 May 2019 - 09:51 PM

Also look for and ever-so-small etching on the corrector, possibly by the marker . The mark/etching goes to the 3 o'clock position as you look at the scope from the corrector end. I had to research that fact for the same reason of having to remove the corrector (that had been removed before by previous owner) in my C-11. There is also a mark on the corrector side of the secondary that goes to the 3 o'clock position.

 

While the corrector was out I drilled and tapped four #8-32 holes and inserted delrin tipped set screws. The 'cardboard' shims I found in place when I originally removed the corrector indicated to me that I didn't have much to lose. I'm looking to buy/use a HOTECH Advanced CT Laser Collimator to get the alignment/collimation right. I'm really close, but would like to verify the adjustment(s).

 

EDIT:

OH! And welcome to Cloudy Nights! Your source of remedies for heartache, frustration, stupidity, and general 'noobosity' (noobocity?)...welcome.gif


Edited by Dynan, 20 May 2019 - 09:56 PM.

  • PrestonE, Neptune and Oops! like this

#5 Oops!

Oops!

    Lift Off

  • -----
  • topic starter
  • Posts: 3
  • Joined: 20 May 2019
  • Loc: Idaho

Posted 21 May 2019 - 12:09 AM

Yes there is an etching near the marker line! I will start there!  Great idea with the set screws. I knew I could count on Cloudy Nights to steer me in the right direction!

Thank you all!

Dave



#6 Dynan

Dynan

    Mercury-Atlas

  • *****
  • Posts: 2537
  • Joined: 11 Mar 2018
  • Loc: NOLA

Posted 21 May 2019 - 12:34 AM

If you go the set screw route, MAKE SURE you reclaim ALL of the drilled metal! (Vacuum as you drill, vacuum after, duct tape to pick up the remnants, etc. You CANNOT be too careful or clean. You don't want any shavings in the OTA!


Edited by Dynan, 21 May 2019 - 09:52 AM.


#7 Oops!

Oops!

    Lift Off

  • -----
  • topic starter
  • Posts: 3
  • Joined: 20 May 2019
  • Loc: Idaho

Posted 21 May 2019 - 09:43 AM

Thanks for the advice!


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics





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



Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics