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 C9.25 f/10 Secondary with Metric Collimation Screw Threads and “Trifid” Fastar HousingPart:
Celestron 9.25” (23.5 cm) f/10 SCT versions with "Trifid" Fastar secondary housingKnobs:
Black plastic, 15 mm (5/8”) diameterThreads:
- These knobs fit the Celestron 9.25” f/10 SCT with a Fastar secondary which has black Phillips factory collimation screws that are recessed into the secondary housing. These versions may or may not have EdgeHD optics.
- 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.
- Knobs include a set of long spacers so they sit slightly above the rotary cover opening.
- 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.