{"product_id":"bobs-knob-for-common-newtonian-primary","title":"Bob's Knob for Common Newtonian Primary (Starfield  \u0026 GSO 6\" to 16\")","description":"\u003ch2\u003eBob's Knob for Common Newtonian Primary\u003c\/h2\u003e\n\u003cp\u003eCommon 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 \u003ca title=\"MLBFactoryScrews\" href=\"http:\/\/www.bobsknobs.com\/Newt\/styled-2\/page127\/index.html\"\u003efactory primary collimation screws\u003c\/a\u003e. If your telescope has \u003ca title=\"MLBFactoryKnobs\" href=\"http:\/\/www.bobsknobs.com\/Newt\/styled-2\/page36\/index.html\"\u003efactory primary collimation knobs\u003c\/a\u003e, these knobs will not fit because the factory knobs have a different diameter.\u003cbr\u003e\u003cbr\u003eOur 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 \u003cu\u003e\u003ca title=\"Custom Knobs\" href=\"http:\/\/www.bobsknobs.com\/page59\/custom.html\"\u003ecustom knobs\u003c\/a\u003e\u003c\/u\u003e 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.\u003cbr\u003e\u003cbr\u003eWe 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.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003cstrong\u003eA. Knobs for Common Newtonian 8” Primary\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFits:\u003c\/strong\u003e\u003cspan\u003e 8” \u003c\/span\u003e\u003cspan\u003eNewtonian telescopes manufactured by Guan Shen Optical (GSO), including Meade LIghtbridge, Hardin Optical, and Zhumell.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003ePrimary collimation\u003c\/strong\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cul class=\"dashed\"\u003e\n\u003cli\u003e\n\u003cspan\u003eKnobs:\u003c\/span\u003e\u003cspan\u003e Black plastic, 30 mm (1-1\/4”) diameter, 5-point fluted\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eThreads:\u003c\/span\u003e\u003cspan\u003e Plated steel\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003ePrimary Lock\u003c\/strong\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cul class=\"dashed\"\u003e\n\u003cli\u003e\n\u003cspan\u003eKnobs: \u003c\/span\u003e\u003cspan\u003eBlack plastic, 25 mm (1”) diameter, knurled\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eThreads:\u003c\/span\u003e\u003cspan\u003e Stainless steel\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eNotes:\u003c\/strong\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003col class=\"arabic-numbers\"\u003e\n\u003cli\u003e\u003cspan\u003eThese 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.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp style=\"text-align: left;\" data-mce-style=\"text-align: center;\"\u003e\u003cspan\u003e_____________________________\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eB. Knobs for Common Newtonian 10” Primary\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFits:\u003c\/strong\u003e 10” Newtonian telescopes manufactured by Guan Shen Optical (GSO), including Meade LIghtbridge, Hardin Optical, and Zhumell.\u003cstrong\u003e\u003cspan\u003e\u003cbr\u003e\u003cbr\u003e\u003c\/span\u003e\u003cspan\u003ePrimary collimation\u003cbr\u003e\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul class=\"dashed\"\u003e\n\u003cli\u003e\n\u003cspan\u003eKnobs:\u003c\/span\u003e\u003cspan\u003e Black plastic, 30 mm (1-1\/4”) diameter, 5-point fluted\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eThreads:\u003c\/span\u003e\u003cspan\u003e Plated steel\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003ePrimary Lock\u003cbr\u003e\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul class=\"dashed\"\u003e\n\u003cli\u003e\n\u003cspan\u003eKnobs: \u003c\/span\u003e\u003cspan\u003eBlack plastic, 25 mm (1”) diameter, knurled\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eThreads:\u003c\/span\u003e\u003cspan\u003e Stainless steel\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp style=\"text-align: left;\" data-mce-style=\"text-align: center;\"\u003e\u003cspan\u003e_____________________________\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eC. Knobs for Common Newtonian 12” Primary\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFits:\u003cspan\u003e 12” \u003c\/span\u003e\u003cspan\u003eNewtonian telescopes manufactured by Guan Shen Optical (GSO), including Meade LIghtbridge, Hardin Optical, and Zhumell.\u003cbr\u003e\u003cbr\u003e\u003c\/span\u003e\u003cspan\u003ePrimary collimation\u003cbr\u003e\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul class=\"dashed\"\u003e\n\u003cli\u003e\n\u003cspan\u003eKnobs:\u003c\/span\u003e\u003cspan\u003e Black plastic, 30 mm (1-1\/4”) diameter, 5-point fluted\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eThreads:\u003c\/span\u003e\u003cspan\u003e Plated steel\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003ePrimary Lock\u003cbr\u003e\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul class=\"dashed\"\u003e\n\u003cli\u003e\n\u003cspan\u003eKnobs: \u003c\/span\u003e\u003cspan\u003eBlack plastic, 25 mm (1”) diameter, knurled\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eThreads:\u003c\/span\u003e\u003cspan\u003e Stainless steel\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ch3\u003e\u003cspan\u003eIn the Box :\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cspan\u003eKnob for selected primary Newtonian mirror size :\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003eFor Newtonian 8\" Primary\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eFor Newtonian 10\" Primary\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eFor Newtonian 12\" Primary\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Bob's Knobs","offers":[{"title":"For Newtonian 8\"","offer_id":44180599210213,"sku":"BOB-MLB8pri","price":49.0,"currency_code":"CAD","in_stock":true},{"title":"For Newtonian 10\"","offer_id":44180599406821,"sku":"BOB-MLB10pri","price":49.0,"currency_code":"CAD","in_stock":true},{"title":"For Newtonian 12\"","offer_id":44180599439589,"sku":"BOB-MLB12pri","price":49.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/products\/bob-s-knob-for-common-newtonian-primary-astronomy-plus-1.jpg?v=1715808972","url":"https:\/\/istronomyplus.com\/products\/bobs-knob-for-common-newtonian-primary","provider":"Astronomy Plus – Telescopes \u0026 Astrophotography Canada","version":"1.0","type":"link"}