Bob's Knobs for Celestron C8 f/10 EdgeHD 8" Secondary

Stock count is accurate & shown in real time.
- This item is out of stock.
- Sign up for back-in-stock alerts to be notified when this item becomes available.
- This item is out of stock.
- We have no ETA from the manufacturer at this time.
- Sign up for back-in-stock alerts to be notified when this item becomes available.
Lower 48 States:
Orders over $50 ship free within the Lower 48 using a carrier and service we select based on your items and delivery location. Faster shipping options may be available at checkout.
U.S. Outside the Lower 48 (AK, HI, PR):
Free shipping on orders over $50 applies to many—but not all—items. Add items to your cart and enter your ZIP code to see available shipping options and any costs.
International Orders:
Free shipping does not apply to international orders. You’ll see available shipping options and costs during checkout. Some items can’t be shipped internationally due to size or manufacturer restrictions. Duties, taxes, brokerage fees, and tariffs are not included and are the customer’s responsibility.
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: C8edgBO
Fits: Celestron 8" (20 cm) f/10 SCT with Fastar secondary and EdgeHD optics.
Knobs: Black oxide steel, 12 mm (1/2") diameter
Threads: Black oxide steel
Notes:
- 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.
- Black oxide steel is for dry environments. Lightly oil the knob top and knob serrations periodically as an anti-corrosion measure.
- The factory dust cover will fit normally with Bob's Knobs installed.
Other Information
- Country of Manufacture: United States
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: C8edgBO
Fits: Celestron 8" (20 cm) f/10 SCT with Fastar secondary and EdgeHD optics.
Knobs: Black oxide steel, 12 mm (1/2") diameter
Threads: Black oxide steel
Notes:
- 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.
- Black oxide steel is for dry environments. Lightly oil the knob top and knob serrations periodically as an anti-corrosion measure.
- The factory dust cover will fit normally with Bob's Knobs installed.
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: C8edgBO
Fits: Celestron 8" (20 cm) f/10 SCT with Fastar secondary and EdgeHD optics.
Knobs: Black oxide steel, 12 mm (1/2") diameter
Threads: Black oxide steel
Notes:
- 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.
- Black oxide steel is for dry environments. Lightly oil the knob top and knob serrations periodically as an anti-corrosion measure.
- The factory dust cover will fit normally with Bob's Knobs installed.
Other Information
- Country of Manufacture: United States
| Free Shipping Graphic | Free US Shipping |
|---|---|
| Hide Found a better Shipped Price on Frontend? | No |

Bob's Knobs for Celestron C8 f/10 EdgeHD 8" Secondary


















