Bob's Knobs for Celestron C11 f/10 with Flat Secondary Housing and Standard Collimation Screw Threads
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 (account login required).
- This item is out of stock.
- Sign up for back-in-stock alerts to be notified when this item becomes available (account login required).
Contiguous US / Lower 48:
Free shipping applies to orders over $50 using our chosen carrier/method. Faster paid options are available at checkout.
Alaska, Hawaii & US Territories:
Free shipping applies to many—but not all—products. Enter your ZIP code in cart or upon checkout to confirm options and costs.
International:
International orders do not qualify for free shipping. Shipping, duties, brokerage, tariffs, and taxes are the customer’s responsibility. Some items may be restricted due to export, size, or manufacturer limitations.
Special Note: The Celestron 11” SCT uses either standard 6-32 or metric M3 collimation screws. Allen, most silver Phillips, and set-style factory collimation screws have standard threads. Most black Phillips screws are metric. See our hints for more information.
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: C11std
Fits: Celestron 11” (28 cm) f/10 SCT versions (metal or carbon fiber tube) with flat secondary housing and standard collimation screw threads (not for CPC 1100 or EdgeHD). Does not fit the Starizona Hyperstar secondary.
Knobs: Black plastic, 16 mm (5/8") diameter
Threads: Black anodized aluminum alloy
Notes:
- Silver factory collimation screws (see second photo) usually have standard threads, but some silver Phillips screws have metric threads. Our hints will help you determine which screws are on your telescope. Make sure the knob threads match the factory screw threads before installing the knobs.
- The factory dust cover will fit normally with Bob's Knobs installed.
- Celestron 11" SCTs manufactured prior to 2006 have standard collimation screw threads.
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: C11std
Fits: Celestron 11” (28 cm) f/10 SCT versions (metal or carbon fiber tube) with flat secondary housing and standard collimation screw threads (not for CPC 1100 or EdgeHD). Does not fit the Starizona Hyperstar secondary.
Knobs: Black plastic, 16 mm (5/8") diameter
Threads: Black anodized aluminum alloy
Notes:
- Silver factory collimation screws (see second photo) usually have standard threads, but some silver Phillips screws have metric threads. Our hints will help you determine which screws are on your telescope. Make sure the knob threads match the factory screw threads before installing the knobs.
- The factory dust cover will fit normally with Bob's Knobs installed.
- Celestron 11" SCTs manufactured prior to 2006 have standard collimation screw threads.
Special Note: The Celestron 11” SCT uses either standard 6-32 or metric M3 collimation screws. Allen, most silver Phillips, and set-style factory collimation screws have standard threads. Most black Phillips screws are metric. See our hints for more information.
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: C11std
Fits: Celestron 11” (28 cm) f/10 SCT versions (metal or carbon fiber tube) with flat secondary housing and standard collimation screw threads (not for CPC 1100 or EdgeHD). Does not fit the Starizona Hyperstar secondary.
Knobs: Black plastic, 16 mm (5/8") diameter
Threads: Black anodized aluminum alloy
Notes:
- Silver factory collimation screws (see second photo) usually have standard threads, but some silver Phillips screws have metric threads. Our hints will help you determine which screws are on your telescope. Make sure the knob threads match the factory screw threads before installing the knobs.
- The factory dust cover will fit normally with Bob's Knobs installed.
- Celestron 11" SCTs manufactured prior to 2006 have standard collimation screw threads.
Other Information
- Country of Manufacture: United States
Bob's Knobs for Celestron C11 f/10 with Flat Secondary Housing and Standard Collimation Screw Threads