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.
C6 f/10 Secondary with Metric Collimation Screw ThreadsPart:
C6BO (black oxide steel); C6SS (stainless steel)Fits:
Celestron 6” (15 cm) f/10 SCT versions (C6-A-XLT, C6-GT, C6-S, C6-SE, C6-SGT, others)Knobs:
Black oxide steel (black) or stainless steel (silver), 12 mm (1/2”) diameterThreads:
Black oxide or stainless steelNotes:
- All versions of the Celestron C6 SCT have collimation screws with metric threads.
- 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.
- The factory dust cover will usually fit properly with Bob’s Knobs installed. However, some very early versions of this design have very little clearance between the factory dust cover and the secondary housing. To make room for the knobs, contact us for a free set of spacers that attach to the ring around the corrector plate to move the dust cover slightly away from the secondary assembly. These spacers are not needed for most versions of this telescope.