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Agena Crayford Focuser Adapter for Celestron C100ED Refractor

4.9 (19 Reviews) Read Reviews Write Review
Brand Agena AstroProducts
Part Number -
Availability available

Product Info

Manufacturer Description

The Celestron C100ED refractor is an excellent telescope. However, owners have long complained of the poor quality of the telescope's stock R&P focuser as its weakest point. Complicating the matter further is the fact that the stock focuser screws into the rear of the telescope tube. Unlike 95% of the other telescopes in the market, the focuser does not bolt to the tube. For those looking to upgrade the focuser, the only alternative until recently was to upgrade to a competing Crayford focuser + adapter costing over $300 - over half the cost of the entire telescope itself!

However, with Agena's new coupling adapter for the Celestron C100ED, you can now attach the very affordable and excellent 86mm GSO Crayford focuser to the C100ED in a few minutes. Installation is easy - just unscrew the stock R&P focuser from the Celestron C100ED tube, screw this adapter into the tube in its place, slide the GSO focuser into this adapter, and bolt it to the adapter using three M4 screws (included with the adapter). The only tool you need to provide is a Philips (cross-head) screwdriver. This upgrade will turn your C100ED telescope into the little beauty it was meant to be.

This adapter will work with GSO's single or dual speed Crayford focusers that have an 86mm flange/base plate (focuser sold separately). It is precision CNC-machined from aluminum and anodized black to match the surface finish of the C80ED tube.

Relative to the stock R&P focuser, the GSO Dual-Speed Crayford/Agena Adapter combination will allow 22mm of additional in-focus travel which is a plus for imaging applications. On the flip side, our configuration will provide 7mm less of back-focus travel compared to the stock focuser but this is easily remedied with an extension tube, if necessary.

If you upgrade your stock C100ED focuser, note that you will loose the built-in finder base on the stock C100ED focuser body when you remove it. To use a finder, you will have to mount a finder bracket directly on the telescope tube, or you can mount it on the GSO focuser body using a special dovetail base (sold separately).

Important Note:

- Before ordering this item, please make sure you can unscrew the stock focuser from your telescope tube. It can be very stiff on some C100ED telescopes due to poor machining of threads, and a couple of people have been unable to unscrew the original R&P focuser from their telescope.

Reviews

4.9 (Based on 19 Reviews) 100% of reviewers recommended this product.
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    1. Guest

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      Review by Jerome A.
      1523073691
      Apr 6, 2018

      4.0 Couldn't use, but good Reasonable

      Pros:

      Cons:

      Comments:

      Couldn't use, but good Reasonable adapter,

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    2. Guest

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      Review by Mihai R.
      1508397272
      Oct 19, 2017

      5.0 Perfect match for a long needed upgraded

      Pros:

      Cons:

      Comments:

      My C80ED has never been so happy :)

      This adapter fits like a glove, and now, with the dual speed 2" GSO Crayford focuser in place, the stars finally stay put whenever i go through various focus points (native, with reducer, with Barlow lens, extensions etc). And this ring made it all happen. Highly recommend if you are planning to revamp your refractor. Nice black shiny finish matches the OTA look. Plenty of clearance for both fitting thread and focuser mounting holes; although holes' position pushes the focuser 0.5mm back, away from face-to-face contact with the ring, but that's fine since it won't cause any tilt - i might just add a thin gasket in there.

      "Let's make the ED80 great again!" :))

      p.s.: no offense, Celestron (or Synta, or whoever..) - aside from the fancy look, that R&P is a joke.. not for low-power visual observations though, but the scope can perform better than just that; at least now it does :)

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    3. Guest

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      Review by Keith H.
      1504070379
      Aug 29, 2017

      5.0 Solid feel and machined well.

      Pros:

      Cons:

      Comments:

      Solid feel and machined well. Installed easily. Very suitable for casual visual observing with small grab and go telescope.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    4. Guest

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      Review by Giulio P.
      1503517459
      Aug 23, 2017

      5.0 Total satisfaction

      Pros:

      Cons:

      Comments:

      As soon as the long sought connection ring for my Celestron 80mm ED became available, I was informed by the staff and could finally buy it, together with a new 2" focuser. Agena Astro knows how to take care of its customers.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    5. Guest

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      Review by Skyhiker
      1496951238
      Jun 8, 2017

      5.0 Works and looks great

      Pros:

      Cons:

      Comments:

      I had been wanting to replace my stock focuser on my Celestron 100ED, but I had a version where the focuser threads on to the barrel, rather than attaching with three screws. Took surprisingly long to find this very simple adapter. One end has threads on its interior, so it screws on to the telescope tube, right where your stock rack and pinion focuser was. The other end has three holes drilled at 120 degree distances, and the kit comes with three screws that will hold your GSO Crayford sturdily in place. It is literally a five minute swap, assuming you have a Phillips head screw driver. In fact, if you are poorly organized, you'll spend more time looking for your screw driver than you will doing the swap out. :D

      Also nice is that the finish of the adapter is the same shade of black as the 100 ED tube and the Crayford focuser. When you're done, it looks natural, like that's the way the telescope was always intended to look.

      I still need to work out the tension adjustments of the actual Crayford focuser, but I am completely happy with this adapter.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    6. Guest

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      Review by Joe D.
      1495452188
      May 22, 2017

      5.0 A great adapter for the C80ED

      Pros:

      Cons:

      Comments:

      The adapter fits perfectly and looks like it is meant to be part of the scope. It opens the possibilities for Crayford single and dual speed focusers to be added to the scope. A must have for C80ED owners.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    7. Guest

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      Review by Frank B.
      1482616585
      Dec 24, 2016

      5.0 Perfect!

      Pros:

      Cons:

      Comments:

      Fits perfect, works great with GSO focuser!

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    8. Guest

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      Review by Todd B.
      1482588547
      Dec 24, 2016

      5.0 Focuser adapter for C80ED

      Pros:

      Cons:

      Comments:

      Bought this for my C80ED- worked like a charm! Screws right onto the scope tube. Nice to have a dual speed focuser on the C80!

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    9. Guest

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      Review by Ed of Tarrytown NY.
      1336953600
      May 13, 2012

      5.0 Adapter made good things possible

      Pros:

      Cons:

      Comments:

      This adapter seamlessly let me upgrade from a rack and pinion focuser threaded to the telescope tube to a more precise Crayford style focuser attached with conventional screws.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    10. Guest

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      Review by Marvaz of Watford, United Kingdom.
      1306627200
      May 28, 2011

      5.0 I would like to buy this product again.

      Pros:

      Strong Construction

      Cons:

      Comments:

      Simply fantastic product.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    11. Craig

      Craig New Member

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      Review by Scope up north of Calgary Alberta Canada.
      1306627200
      May 28, 2011

      5.0 Required upgrade:)

      Pros:

      Well finished,Accuratly made,Easy to install

      Cons:

      None in my instance

      Comments:

      Very nice item that makes upgrading from the stock 'clunker' focuser to the lighter and smoother crayford an easy task.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    12. Guest

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      Review by Ilias of Athens, Greece.
      1294012800
      Jan 2, 2011

      5.0 Fits like a glove

      Pros:

      Strong Construction,Accurate,Compact

      Cons:

      Comments:

      Excellent construction, fit and finish! It worked great!

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    13. Guest

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      Review by laser of England.
      1294012800
      Jan 2, 2011

      5.0 Upgrade your Celestron C100 ED

      Pros:

      Accurate,Precision,Strong Construction,Compact

      Cons:

      Comments:

      A precision engineered and finished adapter that allows you to bolt on (for relatively low cost) a GSO dual Crayford focuser to the older Celestron C100 ED telescopes. This adapter fitted easily to the tube once I had carefully unscrewed the original focuser. I have heard some Celestron ED tubes have different threads, but the adapter screwed ok on to mine. My only gripe was that the adapter was out of stock when I ordered and took many weeks to come back into stock which was frustrating. Communication with Agena is excellent.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    14. Guest

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      Review by Coco of United Kingdom.
      1292889600
      Dec 20, 2010

      5.0 C80 Essential Add-on

      Pros:

      Accurate,Quality Lenses,Compact,Strong Construction

      Cons:

      Comments:

      This is the essential a piece needed to marry the C80 tube to the GSO focuser, its well made and matches the anodising of the GSO Crayford focuser. Very well made.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    15. Guest

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      Review by Aragorn of Denver, CO.
      1271289600
      Apr 14, 2010

      4.0 Great adapter, looks great too

      Pros:

      Right product and price,Perfect Fit

      Cons:

      Comments:

      This adapter is the perfect fit for our Celestron C80ED, whose original focuser left a lot to be desired. Combined with the dual-speed Crayford focuser, it has completely changed our scope for the better.

      Highly recommended.

      Agena's service has always been outstanding too.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    16. jshalpha

      jshalpha New Member

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      Review by James of California.
      1266883200
      Feb 22, 2010

      5.0 Works well and looks great

      Pros:

      Compact,Accurate,Strong Construction

      Cons:

      Comments:

      I read the caution about poor threads on the C80ED that could result in the adapter not screwing on well. However for my scope the adapter went on very smoothly and completely. There were no exposed threads left after the installation. This is a great way to adapt another focuser to this scope.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    17. Guest

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      Review by BradleyB of Olympia, WA.
      1257984000
      Nov 11, 2009

      5.0 Adapt your adapter

      Pros:

      Compact,Well Made

      Cons:

      Comments:

      The description for this item mentions that it may not fit well on some of the C80ED's tubes. Well in actuality, some of the C80ED's tubes were apparently made with completely different threads, not just poor threads. Mine was one such tube. However, since I really wanted to use the new focuser I purchased, I made this adapter work anyway. I did this by filing down the threads on the telescope tube (not completely, only enough so the adapter fits on) and used epoxy to glue the adapter onto the tube. Make sure that the adapter bottoms out on the edge of the tube to make sure it's aligned properly. This worked like a charm. After a suitable time to cure the adhesive, the new focuser screwed right into the adapter and I was good to go.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    18. Guest

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      Review by Antony of United Kingdom.
      1257897600
      Nov 10, 2009

      5.0 Does exactly what is needed

      Pros:

      Looks great,Does perfect job,Affordable

      Cons:

      None

      Comments:

      All I can say about the adapter ring is basically that it does exactly what is needed and is finished off very nicely and perfectly matches the 'scope in all ways.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    19. Guest

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      Review by Ron of Wilson, NC.
      1257724800
      Nov 8, 2009

      5.0 Works great.

      Pros:

      Accurate,Strong Construction

      Cons:

      Comments:

      The adapter mounted up to my Celestron 80ED very smoothly with no trouble.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

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