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Newtonian on GEM tube ring modification

Discussion in 'Telescopes and Mounts' started by Nebula, Jun 16, 2017.

Newtonian on GEM tube ring modification

Started by Nebula on Jun 16, 2017 at 4:02 PM

21 Replies 4716 Views 0 Likes

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  1. Nebula

    Nebula Well-Known Member

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    Hello, I am looking for the tutorial on how to add an extra set of rings on my telescope, to be able to pivot the tube while it's at an angle, and making it easier to work with the GEM.

    Dave in Vermont, maybe you know there is a PDF from Astrobaby, I can't find it anywhere right now... It has the whole modification procedure..

    Thanks.
     
  2. Dave In Vermont

    Dave In Vermont Well-Known Member

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    I just found burning flare from your flare-gun in my lap, Neb! I've got hunting this down on my ToDo-List!

    I'll let you know a.s.a.p,

    Dave
     
    Zigarro likes this.
  3. Dave In Vermont

    Dave In Vermont Well-Known Member

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    Neb - no found one from Astro_Baby, though I'll keep my eyes peeled. You wouldn't believe the GIG's of material I've got - though generally well-organized - but not seeing that particular one. And her site has been down a long while. Have you considered a flare in other places? But all is NOT lost.....

    I did locate another very good tutorial on constructing such with easy-to-find materials and minimal mechanical-skills. So this may well solve your situation:

    How to Install Wilcox Rotating Rings.pdf

    Let me know how this does for you?

    Thanks!

    Dave - File Clerk hat on...
     

    Attached Files:

  4. Nebula

    Nebula Well-Known Member

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    Hello! thanks Dave for this alternative solution. It seems like a much less expensive solution and new rings are 100CAD for 2 which I think it's quite expensive for what they are.

    But there is a second problem with my tube, in order to balance it and depending of the position, especially pointing the zenith and using 2" eyepiece, i have to slide the tube horizontally too, not just rotating it to have better EP position.... it can be really really exhausting to use some day.
     
  5. Dave In Vermont

    Dave In Vermont Well-Known Member

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    Perhaps a sort of series of PTFE-ball-bearings in some kind of elastic cord with tightness-adjustment.....I'll think about some sort of solution. I LOVE problems like this! :p

    As for prices: As soon as you put the word 'ASTRO' in front of a product - the price becomes 'astronomical!' I always look for the item I need WITHOUT that word in the equation. Heaven <koff!> knows how much $$$ I've saved by this!

    See ya 'round the Universe!

    Dave
     
  6. Nebula

    Nebula Well-Known Member

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    I saw a nice solution on SGL which I prefer over the Wilcox concept.

    [​IMG]

    He used a thin plastic ruler has a stopper and it's clearing the bolt of the existing tube ring, without modifications to it. I like that very much and if I could find something else 1/8" thick to do the same thing.

    Otherwise I am not going to pay 75$ +tx +shipping for 2 rings, it's overpriced, I am not the Santa Claus... crazy world.
     
  7. Dave In Vermont

    Dave In Vermont Well-Known Member

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    Looks good to me! Can you find me a link to this piece in SGL? I'd like to get a copy made and add it to my 'Miles-'O-Files' of such. I thought I'd spotted something similar in there, but couldn't locate it when I looked yesterday for it.

    Good job!

    Dave
     
  8. Nebula

    Nebula Well-Known Member

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  9. Dave In Vermont

    Dave In Vermont Well-Known Member

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    Thanks! But which one in particular are you going with? I noted this thread started in 2012. Some are deceased. If it's a written-word piece in the thread, I'll see if I can't consolidate it into a step-by-step sheet.

    Thanks!

    Dave
     
  10. Nebula

    Nebula Well-Known Member

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    Hi Dave,
    I started my own project today, molding a lexan strip. I built the template out of wood today, but with the wrong dimensions... I have to start all over again. Anyway my jigsaw is a really poor tool, i am going to cut the new template (with the right dimension) tomorrow at the workshop.

    Tomorrow it should be done.

    The materials can be found at the hardware store, no problems or special hard to find parts, it's going to be great for me I assure you. If my concept is good, ill do a walk trough PDF also.
     
  11. Dave In Vermont

    Dave In Vermont Well-Known Member

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    Ah! Good deal! I was going to suggest you craft a step-by-step guide! I see you're already on it.

    Great minds.....

    Dave
     
  12. Nebula

    Nebula Well-Known Member

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    Yes ! i am a fan of open source also!

    So far so good, this is a test I did about 15 minutes ago the strip of Lexan is melting around the template, when the plastic is really hot it's fairly easy to do while pulling the end. It Took maybe 10 minutes to achieve this result.

    It should work perfectly!

    [​IMG]

    [​IMG]

    [​IMG]
    Final result for the test, beautiful shape. For a first experience, I am quite happy :)

    [​IMG]
    [​IMG]
     
  13. Dave In Vermont

    Dave In Vermont Well-Known Member

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    Good Lord!! :eek:

    I am AMAZED!! :D
     
  14. Nebula

    Nebula Well-Known Member

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    ((; glad you like it.

    I just finished cutting the new wheel with a descent machine this time, it's a bit better then the previous version. The dimensions are spot on. 237mm diameter. It's the exact exterior diameter of my telescope.

    [​IMG]
    [​IMG]
     
  15. Nebula

    Nebula Well-Known Member

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    I finished the rotating ring tonight Dave it should do a fine job..

    [​IMG]

    [​IMG]
    I found some felt tissue for the inside at a local textile store, really great product for 2$ it will hold still on the Lexan with some simple stick glue. It's drying right now.
    [​IMG]
    [​IMG]
    [​IMG]
     
  16. Nebula

    Nebula Well-Known Member

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    Dave in Vermont, my project is finished, it's working fine so far, it's a big improvement over the previous condition. The eyepiece is AT LEAST 40% easier to adjust then before without losing balance.. waw it's great :)))

    I did a PDF it's not finished yet.

    Those are the final pictures
    [​IMG]
    [​IMG]

    [​IMG]
     
  17. Dave In Vermont

    Dave In Vermont Well-Known Member

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    It looks amazing - and if it's looks are anywhere near to how well it functions - WOW!

    Please do keep us informed on this project. I'd be happy to add a copy to my 'Miles-O'-Files' for distribution to any & all takers!

    A 'cottage-industry' is born...

    Dave
     
  18. Nebula

    Nebula Well-Known Member

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    Well everything is not perfect. Has discussed previously on SGL, the tube is heavy for the EQ5 so the system has it's limitations. For instance if it's is pointing up, above 45 degrees, it's hard to rotate even with the rotating ring because is not perfectly round and the cast iron rings (or aluminium?) are not round either.. The bottom line is, the tube is quite hard to rotate even in horizontal position.

    BUT the new ring will preserve the balance of the instrument pretty well. and that's major. I need to lift the tube a bit (1/16 of an inch) to help the rotation movement in order to position the EP. (doing so can unfortunately move the RA axis a bit even if it's locked, no big deal)

    The whole process of positioning the eyepiece is easier by maybe 40%. 40% is far from perfect but it's still a major improvement, for 14$ (Of course i already had the tools to build it for that price)

    I need to test it more too but last time it went well. The edge of the ring recieved a rough sanding onlu. The new revision is much smoother with the bench grinder polishing. there is far less friction then on my first attempt.

    Also, my version of the rotating ring should not scratch the paint job of the telescope and there is no need to do any modifications to the existing rings of the telescope which are really expensive. (drilling the ring to recede the bolts inside)
     
    Last edited: Jun 27, 2017
  19. Nebula

    Nebula Well-Known Member

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  20. Dave In Vermont

    Dave In Vermont Well-Known Member

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    Got it! Thank you - filed in enough places for cross-referencing easily.

    Excellent job!!

    Dave
     

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