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How to remove the lens from a Telrad?

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#1 mconnelley

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Posted 29 June 2020 - 06:02 PM

Hello:

  I have a dead Telrad.  It's very dead, for several reasons, and I'm not going to try to further to revive it.  I want to remove the lens to make a split pupil finder.  So far, my efforts to remove the lens have failed.  I don't see any glue holding it in place, but I can't get it budge.  There are two plastic parts helping to hold the lens in place, so my next step was to saw those off then hope maybe the lens falls out.  

 

   Before I start hacking this poor telrad apart, I'd like to ask if there is any out there who's taken the lens out of a telrad, and how they did it.  Thank you.

 

Cheers

Mike 



#2 MellonLake

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Posted 29 June 2020 - 06:07 PM

The glass is held in by something like hot glue. I would warm it up with a hair drier and see if it will slide up and out.

I have taken mine out to clean it just by tugging on it firmly.
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#3 jtsenghas

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Posted 30 June 2020 - 09:25 AM

Are you referring to the convex lens that is at the focal length from the reticule, or the flat rectangular glass window/ mirror "beam splitter"?

 

I pulled the latter out to repair another Telrad and saw only a trace of adhesive on the lowest edge. 


Edited by jtsenghas, 30 June 2020 - 09:25 AM.

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#4 mconnelley

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Posted 02 July 2020 - 03:44 PM

Hello:

  I mean the convex that is at the focal length from the reticule.  I've already pulled out the mirror below the lens, and the glass window above it.  

 

Cheers

Mike



#5 jtsenghas

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Posted 02 July 2020 - 03:54 PM

One of the junk Telrads I was given as a parts instrument actually had that lens bouncing around loose inside. 

 

That makes me think it is not captured in the assembly, but simply adhered from inside. 

 

When I get home today Ì'll look for more clues but I suspect a whack with a soft blunt instrument from the outside may do it. 




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