Celestron 8 inch (20 cm) f/10 SCT with factory Allen, silver Phillips, or headless set-style 6-32 collimation screws, with or without Fastar compatible secondary (C8 orange, black, or gray; Ultima 2000; NexStar 8) . Will not fit scopes with black Phillips factory collimation screws.
The extra images show all compatible systems.
Bob's Knobs - Celestron 8 inch (20 cm) F/10 SCT standard:
- Set van drie Bob's Knobs collimatieschroeven;
- Knoppen: zwart plastic, 13 mm (1/2 inch) diameter;
- Schroefdraad: zwart geanodiseerd aluminium legering.
These knobs will fit all C8 models made prior to 2005, and all 2005 and later models EXCEPT those with black Phillips factory collimation screws. The black-screw model requires C8 metric knobs. Check that our screw threads match the factory screw threads before installing.
The factory dust cover will fit normally with Bob's Knobs installed.
Some telescope versions have a small plastic cover over the factory collimation screws. This cover must be removed and set aside when Bob's Knobs are installed. The cover is cosmetic only and will not affect operation of the scope.
We provide spacers for knobs installed on the Fastar compatible secondary to raise the knobs slightly for easier use. These spacers can be optionally used on other models with Allen or Phillips factory collimation screws to raise the knobs for easier access, but check that the full-aperture dust cover fits without contacting the knobs. Spacers should not be used on telescopes with set-style factory collimation screws.