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

Problem with Helical Focuser on TeleVue Ranger

refractor
  • Please log in to reply
11 replies to this topic

#1 ljohnson

ljohnson

    Lift Off

  • -----
  • topic starter
  • Posts: 4
  • Joined: 25 Apr 2016

Posted 25 April 2016 - 06:17 PM

I recently picked up a brass TeleVue Ranger on a beautiful wood alt-az mount for $100--a good deal, I believe. Everything is in very good condition, except the helical focuser seems to be stuck in the fully extended position. When I try to turn it, it will not budge. I pushed as hard as I dared, but I did not want to damage anything. Does anyone know how to disassemble and fix that helical focuser?


  • Charlespl likes this

#2 jeff gill

jeff gill

    Mariner 2

  • *****
  • Posts: 286
  • Joined: 14 May 2012

Posted 25 April 2016 - 06:38 PM

That's a steal of a deal.  Is it fully extended?  Or fully retracted?  Ive had helical focusers jam when ran all the way out or all the way in, but i wouldn't expect that of a televue focuser, unless it had been left that way for a long time.



#3 sydney

sydney

    Viking 1

  • -----
  • Posts: 656
  • Joined: 07 Apr 2010
  • Loc: Upstate NY

Posted 26 April 2016 - 06:34 PM

I don't remember the specifics, but taking it apart is easy.  Start with the small hex screws (2) on the black ring that's attached on the end of the knurled knob.  I believe that ring then unscrews.  Work your way in from there.  Here are some pics of the parts when I took mine apart to re-grease.

Attached Thumbnails

  • photo 1.JPG
  • photo 2.JPG

  • Piero DP likes this

#4 ljohnson

ljohnson

    Lift Off

  • -----
  • topic starter
  • Posts: 4
  • Joined: 25 Apr 2016

Posted 27 April 2016 - 09:30 AM

Jeff--You were right. The helical focuser had been fully extended and had been left that way for years--the previous owner did not even know that the brass collar was a helical focuser.

 

Sydney--I removed the draw tube assembly, loosened the two set screws in the black ring, and unscrewed the black ring as you suggested. The brass collar was still stuck fast. I called TeleVue tech support to make sure I knew which way I should turn the collar. I then padded the draw tube and clamped it in a metal lathe, padded the brass collar, and forced the brass collar loose with large pliers. Now I just need to remove the original grease, add new grease, and reassemble everything.

 

Thanks for the help!


  • LTZ, Peter Besenbruch and Piero DP like this

#5 KerryR

KerryR

    Soyuz

  • *****
  • Posts: 3868
  • Joined: 05 Dec 2007
  • Loc: West Michigan

Posted 28 April 2016 - 08:45 PM

Good job! That'll be a great scope... even more so at $100-- a real steal!

 

Enjoy!


  • Ravenous likes this

#6 DeSoto Kid

DeSoto Kid

    Vostok 1

  • -----
  • Posts: 104
  • Joined: 24 Aug 2007
  • Loc: DeSoto, Texas

Posted 30 April 2016 - 09:54 PM

Jeff--You were right. The helical focuser had been fully extended and had been left that way for years--the previous owner did not even know that the brass collar was a helical focuser.

 

Sydney--I removed the draw tube assembly, loosened the two set screws in the black ring, and unscrewed the black ring as you suggested. The brass collar was still stuck fast. I called TeleVue tech support to make sure I knew which way I should turn the collar. I then padded the draw tube and clamped it in a metal lathe, padded the brass collar, and forced the brass collar loose with large pliers. Now I just need to remove the original grease, add new grease, and reassemble everything.

 

Thanks for the help!

 

Did TeleVue recommend a grease for your Ranger helical ?

 

Wayne R.

DeSoto, Texas



#7 beanerds

beanerds

    Apollo

  • -----
  • Posts: 1006
  • Joined: 15 Jul 2008
  • Loc: Darwin Australia

Posted 01 May 2016 - 05:41 AM

Good news , I echo the  ' $100 , a steal of a deal ' ) , I hade a Pronto years ago ( same optics ) and it was a jem of a scope .

I still kick myself for selling it ....

 

Brian.



#8 Kutno

Kutno

    Surveyor 1

  • *****
  • Posts: 1590
  • Joined: 17 Aug 2009

Posted 01 May 2016 - 07:37 PM

 

 

Did TeleVue recommend a grease for your Ranger helical ?

 

Wayne R.

DeSoto, Texas

 

 

A while back, when I had a similar question, the gentleman on the phone indicated regular automotive grease.



#9 LTZ

LTZ

    Messenger

  • *****
  • Posts: 487
  • Joined: 01 Jan 2007
  • Loc: Arizona

Posted 16 November 2016 - 02:21 AM

Jeff--You were right. The helical focuser had been fully extended and had been left that way for years--the previous owner did not even know that the brass collar was a helical focuser.

 

Sydney--I removed the draw tube assembly, loosened the two set screws in the black ring, and unscrewed the black ring as you suggested. The brass collar was still stuck fast. I called TeleVue tech support to make sure I knew which way I should turn the collar. I then padded the draw tube and clamped it in a metal lathe, padded the brass collar, and forced the brass collar loose with large pliers. Now I just need to remove the original grease, add new grease, and reassemble everything.

 

Thanks for the help!

I'm experiencing the identical issue with a recently acquired brass Ranger.  I have removed the grub screws and metal ring, but I'm stuck on how to leverage the brass focus ring loose without damaging it.  Does loosening the brass collar / focus ring follow the left loosey righty tighty rule, like the ring or is it opposite?  I don't want to make it worse guessing the wrong way!!  Thanks!!


Edited by LTZ, 16 November 2016 - 02:23 AM.


#10 gillmj24

gillmj24

    Fly Me to the Moon

  • *****
  • Posts: 5182
  • Joined: 06 Dec 2005
  • Loc: PA

Posted 26 April 2018 - 08:22 PM

Me three

#11 gillmj24

gillmj24

    Fly Me to the Moon

  • *****
  • Posts: 5182
  • Joined: 06 Dec 2005
  • Loc: PA

Posted 24 May 2018 - 10:47 PM

Took it apart and was able to work the helical free. Still stiff with the old grease but was usable and good to kbow a regrease (and some brass polish) will make it like new.

#12 Neal Smith

Neal Smith

    Lift Off

  • -----
  • Posts: 2
  • Joined: 28 Sep 2012

Posted 06 November 2019 - 06:10 PM

Anyone know of a Crayford type retrofit for these little Rangers?




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: refractor



Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics