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Bob's Knobs for Celestron C8 f/10 Post-1980 Secondary with Standard Collimation Screw Threads # C8std

5.0 (4 Reviews) Read Reviews Write Review
Brand Bob's Knobs
Part Number C8std
Availability available

Product Info

Manufacturer Description

Collimate your Catadioptric or Newtonian reflector style telescopes without tools!

It's easy...just grab a Bob's Knob collimation thumbscrew and turn. You can even do it while looking through the eyepiece on most scopes. These thumbscrews are also much easier to use with gloves on. And perhaps most importantly, you'll never drop that pesky little Allen wrench or screwdriver into the grass again. Installation is a snap with the included instructions, and you can undo the modification at any time.

Part: C8std
Fits: Celestron 8" (20 cm) f/10 post-1980 SCT with factory Allen or silver Phillips collimation screws, with or without Fastar secondary with silver collimation screws (C8 black, or gray; Ultima 2000; NexStar 8; others). This includes the post-2000 orange-tube. Will not fit pre-1980 orange tube or most scopes with black Phillips factory collimation screws.

Knobs: Black plastic, 13 mm (1/2") diameter
Threads: Black anodized aluminum alloy

Notes:
1. These knobs will fit C8 models made prior to 2005 (except pre-1980 orange tube), and most post-2005 models with silver factory collimation screws.
2. Most models with black Phillips factory collimation screws require C8 metric knobs (Item C below) A few post-2005 scopes have black Phillips collimation screws with standard threads. Here are some hints to help determine which screws your telescope has. Make sure the knob threads match the factory screw threads before installing the knobs. More information is in our Celestron Technical Paper.
3. We provide spacers to raise the knobs slightly for easier use, but the spacers can be omitted if the knobs contact the inside of the full-aperture dust cover. Spacers are required for knobs installed on the Fastar secondary with silver collimation screws for proper clearance.
4. Some telescope versions have a small plastic cover over the factory collimation screws. This cover must be removed and set aside when Bob's Knobs are installed. The cover is cosmetic only and will not affect operation of the scope.

Reviews

5.0 (Based on 4 Reviews) 100% of reviewers recommended this product.
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    1. Guest

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      User Notes:
      Review by Michael G.
      1542379920
      Nov 16, 2018

      5.0 A must for easy collimation!

      Pros:

      Cons:

      Comments:

      great product with fantastic support from AgenaAstro when I had questions as to which product would fit my '90's C8.

      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 George G.
      1534939752
      Aug 22, 2018

      5.0 Agena Astro

      Pros:

      Cons:

      Comments:

      I have always used Bobs Knobs. The best. But for this review its Agena's shipping the gets as always 5 big stars. I am 3000 miles away get stuff so fast it's mindblowing

      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 Robert G.
      1503517417
      Aug 23, 2017

      5.0 They're everywhere!

      Pros:

      Cons:

      Comments:

      I have a set of Bob's Knobs on just about every Celestron cat I have. I don't have to use them often, but it's nice when they are there. In addition to making it easy to re-collimate, it also makes it easy to tweak the collimation a bit to see if a problem is being caused by the collimation being off or not.

      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 Moonrider of FL.
      1390694400
      Jan 25, 2014

      5.0 Must Have for any SCT

      Pros:

      Lightweight,Accurate,Easy to Use

      Cons:

      Comments:

      Makes collimation easy.

      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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