Bob's Knobs Celestron 8'' EdgeHD Collimation Knobs
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Bob's Knobs Celestron 8" EdgeHD Collimation Knobs

  (3 Reviews)
✓ 2 year warranty


3x in stock shipped 1-2 working days

About this product

Model:  bk_c8_edge_met_bo
Part Number:  C8edgBO

Bob's Knobs are the BEST option for tool-free collimation.

Simple to fit and easy to use.

Collimate your telescope without an Allen key or screwdriver!

Instructions are supplied but can also be found online as well as useful FAQ.

Images are representative and may not show the exact knob size / threads.

IMPORTANT: Please ensure the Bob's knobs threads and factory screw threads match before installation.

Knobs for C8 f/10 Secondary with EdgeHD Optics

Part: C8edgBO (black oxide steel); C8edgSS (stainless steel)
Fits: Celestron 8” (20 cm) f/10 SCT with Fastar secondary and EdgeHD optics.

Knobs: Black oxide steel (black) or stainless steel (silver), 12 mm (1/2”) diameter
Threads: Black oxide or stainless steel

  1. These knobs will fit only the Celestron 8” SCT with Fastar secondary and EdgeHD optics. These telescopes are marked “EDGEHD OPTICS” on the corrector ring. Do not use these knobs on the non-EdgeHD Fastar secondary; the screws on these knobs are too long. Be sure to check that the thread length on our knobs matches the thread length on the factory collimation screws.
  2. Black oxide steel (shown in photo) is for dry environments. Lightly oil the knobs periodically as an anti-corrosion measure. Stainless steel provides better corrosion protection in coastal or high humidity areas, or in places where dew or other condensation is common.
  3. The factory dust cover will fit normally with Bob’s Knobs installed.

Customer reviews

Average Rating (3 Reviews):  
Write a Review and share your opinions!

Rating (max 5):  
Make collimating easy
Monday, 2 March 2020  | 

Very easy to use, best Collimation I have got in years. Should have got som earlier.

Rating (max 5):  
Thanks Bob!
Sunday, 18 November 2018  | 

The fear of using a sharp screwdriver at night on my 8" EdgeHD front lens has gone, they may only be simple knobs but they really work. I collimated my EdgeHD within 5 mins first time, I had no idea it was so out, real improvement to my astro photography made possible with these and I will now check this every time I set up. A bit expensive maybe, a quality item with real usefulness - double yes. Thanks Bob (wherever you are!) and FLO of course.

Rating (max 5):  
Perfect Engineering
Monday, 16 April 2018  | 

This is a quality product that does what it should do. Very rapid service from FLO as always


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