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1940s Tinsley Saturn 6" F/20 Cassegrain Restoration

Discussion in 'Vintage Telescopes & Equipment' started by Bomber Bob, Sep 2, 2015.

1940s Tinsley Saturn 6" F/20 Cassegrain Restoration

Started by Bomber Bob on Sep 2, 2015 at 8:28 AM

30 Replies 4519 Views 1 Likes

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  1. Bomber Bob

    Bomber Bob Well-Known Member

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    Up to this scope, my classic telescope restores were minor cosmetic and/or mechanical issues. Here's what I started with:

    Tinsley Saturn 15CM OTA - Bob Midiri P01.jpg

    The OTA shell of a rare - maybe VERY rare - Tinsley Saturn 6" Cassegrain. No mirrors. No mount. Just lots of heavily tarnished & stained brass.
     
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  2. Bomber Bob

    Bomber Bob Well-Known Member

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    The 12 lb rear assembly holds the primary mirror cell and the rotating focuser. Both it and the thick end ring got an all day soak in vinegar, followed by hours of cleaning & polishing:
    Tinsley Saturn - Brass AFTER 1st Polish.jpg
     
  3. Bomber Bob

    Bomber Bob Well-Known Member

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    With the odds of my ever acquiring a Tinsley EQ mount slim to none, I opted to use a vintage 1980s Meade MTS GEM, and fitted it to a tall 4" pipe:
    Tinsley Saturn - Meade GEM on Painted Tall Pedestal.jpg
     
  4. Bomber Bob

    Bomber Bob Well-Known Member

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    Thanks to another forum member, I got a replacement mirror set:
    CN - 15CM CSC P01 - Dirty Mirrors.jpg
     
  5. Bomber Bob

    Bomber Bob Well-Known Member

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    I tested the optics and measured to mirror distances several times before restoring the tube. The color is not blue, it's a mint green & silver, but not to my digital cameras.
    Tinsley Saturn - Official 20150613 CN1.jpg
     
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  6. Bomber Bob

    Bomber Bob Well-Known Member

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    For a lifelong refractor guy, this restoration was a personal challenge: I've never owned a Cassegrain, had heard horror stories for decades about fussy collimation; and, I've never worked on / with 70+ year old brass. But it was worth it - every time I use it confirms that. And... my success with this restore is why I recently bought a 100 - 130 year old all brass 3" refractor. Bring it on! These projects are learning experiences with practical & useful outcomes; and, if I can save a few from the junkyard, that also makes it worth the time & trouble.
     
  7. clintwhitman

    clintwhitman Well-Known Member

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    So JW, That is nothing short of incredible that you were able to find a mirror set to fit this! Is that sticker from L&L optical? I had been to his shop that used to be in laguna Niguel. Nice save bro Tinsley Labs made a couple of my favorite Classics....
     
  8. Bomber Bob

    Bomber Bob Well-Known Member

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    I'd like to find out more about Delta Lambda, and whether Tinsley made 6" Casses on a regular basis, or if mine was a custom order / guide scope for one of their very large reflectors.
     
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  9. LewC

    LewC Well-Known Member

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    If memory serves, the old hotel at Mt. Wilson used to have a Tinsley 8-inch cass. That was before the hotel burned down. I don't know what happened to the cass., but I remember Tommy Cragg or Tom Cave saying that the optics weren't that good.

    One of our Cloudynights buddies, Steve Miller, acquired and restored an 8-inch Tinsley cass. but I never got to look thru it. Steve raved about how good the optics were but has since sold it. Clint Whitman can probably comment on its optical quality.
     
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  10. clintwhitman

    clintwhitman Well-Known Member

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    Side Note: The "Go to first unread" button at the top of the page is great!
    On that note, Steves 8" threw up a very nice image. We had my Uniponds, Dans 6" AP and I think Robert was up on the the mountain also with his 7" AP and Steve's Tinsley Cass kept up just great. As I remember Steve set up and fiddled with the optics for a time and of course Saturn was the first thing on the list.
    I remember being very impressed with the view. Later we star tested the mirrors and setup and it showed and very consistent pattern. The other scope is our 4" Tinsley Saturn, It has one of the best F15 objectives I have ever seen. Every time I test it I get the same result.:)
     
  11. clintwhitman

    clintwhitman Well-Known Member

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    Thats Kinda what I was wondering also. Nothing comes up for DL optical, but maybe the guy moved to Denmark? L&L Optical was in Laguna Nigel for years, Delta"s location is now a sofa shop, but the location looks like where L&L was before he move to Santa Ana....
     
  12. LewC

    LewC Well-Known Member

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    Delta Lambda might show up in old Sky & Telescope ads. If you have the digital collection of S&T, you could find out very quickly. Just a thought.
     
  13. clintwhitman

    clintwhitman Well-Known Member

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    I have the hard copies, Old school. Maybe I will thumb through a few and see if they are there. I have heard the name before but I don't remember where.
     
  14. BruceK

    BruceK New Member

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    FWIW, I found an ad for Tinsley Laboratories in the January 1949 S&T page 77:

    [​IMG]

    BTW - searching on Tinsley for the 40s decade results in numerous hits, not all of them ads (I don't think).
     
    Last edited: Sep 12, 2015
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  15. Bomber Bob

    Bomber Bob Well-Known Member

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    The OTA style is pretty much the same in Tinsley's 1930s catalogs as 15-20 years later. I've yet to find a 6" Cassegrain sold by Tinsley as a regular item - a mystery I'd like to solve!
     
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  16. Bomber Bob

    Bomber Bob Well-Known Member

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    The mirrors are back from Majestic and they both look mighty fine! The secondary had a bunch of linear scratches on one side, and now it is flawless!
    Tinsley Saturn 6 - Mirrors Recoated 20160303.jpg
     
  17. clintwhitman

    clintwhitman Well-Known Member

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    Thats great JW man,,,,, bet your ichin to get that back in the tube.....
     
  18. Bomber Bob

    Bomber Bob Well-Known Member

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    Clint, don't you know it! But I'm not gonna rush it too much: I'm rebuilding & improving the secondary mirror holder by enlarging & extending the baffle, and making a true 360* pivot point. But after last night observing & imaging Jupiter with the Mogey, yeah! I'm ready to put my big gun on the king of planets.
     
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  19. clintwhitman

    clintwhitman Well-Known Member

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    At F20 at least you wont need a 3mm eyepiece to see something...
     
  20. Bomber Bob

    Bomber Bob Well-Known Member

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    Here's the new & improved secondary mirror holder & baffle:
    Tinsley - New Secondary Mount and Baffle CN1.jpg
     
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