The knobs below will fit all versions of the Celestron 6” Schmidt-Cassegrain secondary.
A. Knobs for C6 f/10 Secondary with Metric Collimation Screw Threads
Part: 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”) diameter
Threads: Black oxide or stainless steel
- 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.
$20.95 (black oxide steel)
$25.95 (stainless steel)