Bob's Knob for Common Newtonian Primary
Common Newtonian-style telescope primary configurations: These knobs will fit most Newtonian reflectors made by Guan Sheng Optical, including GSO, Hardin Optical, Meade, and Zhumell models, provided the telescope has factory primary collimation screws. If your telescope has factory primary collimation knobs, these knobs will not fit because the factory knobs have a different diameter.
Our knobs listed here have a screw diameter of 7 mm (collimation) and 6 mm (locking), and will usually fit your telescope if you select the knobs that match your scope’s aperture. If your screws are different, we can design custom knobs for your application. Contact us using the link at the bottom of this page for more information. Price is for a complete set of knobs.
We also offer stronger primary mirror support springs so collimation is retained while the locking screws are backed off for collimation adjustment. See Item D below. Price is for a complete set of springs.
A. Knobs for Common Newtonian 8” Primary
Fits: 8” Newtonian telescopes manufactured by Guan Shen Optical (GSO), including Meade LIghtbridge, Hardin Optical, and Zhumell.
Primary collimation
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Knobs: Black plastic, 30 mm (1-1/4”) diameter, 5-point fluted
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Threads: Plated steel
Primary Lock
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Knobs: Black plastic, 25 mm (1”) diameter, knurled
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Threads: Stainless steel
Notes:
- These knobs will fit telescopes with M7 (7 mm diameter) primary adjustment screws and M6 (6 mm diameter) primary lock screws. These knobs will not fit 8” GSO telescopes that have M5 (5 mm diameter) primary adjustment screws.
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B. Knobs for Common Newtonian 10” Primary
Fits: 10” Newtonian telescopes manufactured by Guan Shen Optical (GSO), including Meade LIghtbridge, Hardin Optical, and Zhumell.
Primary collimation
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Knobs: Black plastic, 30 mm (1-1/4”) diameter, 5-point fluted
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Threads: Plated steel
Primary Lock
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Knobs: Black plastic, 25 mm (1”) diameter, knurled
-
Threads: Stainless steel
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C. Knobs for Common Newtonian 12” Primary
Fits: 12” Newtonian telescopes manufactured by Guan Shen Optical (GSO), including Meade LIghtbridge, Hardin Optical, and Zhumell.
Primary collimation
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Knobs: Black plastic, 30 mm (1-1/4”) diameter, 5-point fluted
-
Threads: Plated steel
Primary Lock
-
Knobs: Black plastic, 25 mm (1”) diameter, knurled
-
Threads: Stainless steel
In the Box :
Knob for selected primary Newtonian mirror size :
- For Newtonian 8" Primary
- For Newtonian 10" Primary
- For Newtonian 12" Primary
