Bob's Knobs for C11 f/10 with “Trifid” Fastar Secondary Housing and Metric Collimation Screw Threads
Collimate your Schmidt Cassegrain Telescope without special tools when you use Bob's Knobs! It's easy: Just grab a Bob's Knob Collimation Thumbscrew and turn it. You can even do it while looking through the eyepiece on many scopes. 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 if you wish. The factory dust cover will fit normally with Bob's Knobs installed on your secondary.
- Installation is a snap with the included instructions
- Modification can be undone at any time
- Knobs are crafted from black plastic, black oxide steel (black) and/or stainless steel (silver)
- No tools required to perform a collimation!
These Bob's Knobs C11metfst screws will fit the Celestron 11” (28 cm) f/10 SCT versions (metal or carbon fiber tube) with metric thread collimation screws and "Trifid" rotary cover Fastar secondary housing. Factory collimation screws are silver Phillips.
These knobs will fit the C11 with EdgeHD optics. They will also fit the C11 with Starizona Hyperstar if the collimation screws have metric threads.
Knobs: Black plastic, 16 mm (5/8”) diameter
Threads: Black anodized aluminum alloy
- These telescopes can have factory collimation screws with either standard or metric threads. Most models with black Phillips collimation screws have metric threads. There are a few black Phillips screws with standard threads. If you discover your knobs have the wrong threads, you may return your knobs for exchange at no additional cost. Alternatively, you can order knobs with both standard and metric thread screws and return the unused set for a full refund.
- Collimation screws on these telescopes are small with very fine threads. Knobs must be tightened gently (just enough to hold the secondary in place) to prevent damage to either the knob or secondary assembly.
- The factory dust cover will fit normally with Bob’s Knobs installed.
- The rotary secondary cover must remain open when the knobs are installed. The cover is cosmetic only and will not affect operation of the telescope.