{"product_id":"rb-focus-carbon-fiber-double-spider","title":"RB-Focus Carbon Fiber Double Spider","description":"\u003ch1\u003eRB-Focus Carbon Fiber Double Spider\u003c\/h1\u003e\n\u003cp\u003eThe RB-Focus Carbon Fiber Double Spider is a replacement secondary mirror spider for Newtonian reflectors, built from stainless steel and carbon fibre around a double-vane design. It is made for astrophotographers who want their Newtonian to hold collimation, resist temperature swings and produce clean diffraction spikes, without giving up the simplicity of the optical design they already use.\u003c\/p\u003e\n\u003ch2\u003eThinner vanes, stiffer structure\u003c\/h2\u003e\n\u003cp\u003eThe double-vane layout made it possible to cut the thickness of each vane down to just 0.5 mm, which reduces obstruction and weight. At the same time the secondary holder is stiffer and more stable than the standard arrangement, so the mirror stays where it was set through long sessions, repeated trips to the field and the ordinary handling that normally nudges a Newtonian out of alignment.\u003c\/p\u003e\n\u003ch2\u003eBuilt for changing temperatures\u003c\/h2\u003e\n\u003cp\u003eCollimation shifts caused by temperature are one of the quieter frustrations of the design: everything is perfect at dusk and slightly off by three in the morning. Because the spider is made largely of carbon fibre — light and extremely rigid — it is highly resistant to temperature change, so collimation and focus remain intact as the night cools down instead of drifting with the tube.\u003c\/p\u003e\n\u003ch2\u003eWhat the double vanes do to your stars\u003c\/h2\u003e\n\u003cp\u003eThe first reaction to a double-vane spider is usually the fear of doubled diffraction spikes. In practice the paired vanes cancel when the image is focused, leaving elongated, fine diffraction spikes that give stars a stylised, subtle look — a trait that appeals to imagers who dislike the heavy cross produced by thick single vanes. Because the spikes only resolve cleanly at focus, the pattern doubles as a focusing aid: when the spikes are sharp and tight, the telescope is in focus.\u003c\/p\u003e\n\u003ch2\u003eCollimation in seconds, not evenings\u003c\/h2\u003e\n\u003cp\u003eThe spider uses four collimation points with factory bob knobs and a modified clutch system, which makes the whole alignment process much more controllable than pushing a secondary around by hand. Squaring the focuser and aligning the secondary mirror becomes a matter of small, repeatable adjustments, and a perfect diagonal alignment can be reached in a matter of seconds rather than an hour of trial and error.\u003c\/p\u003e\n\u003ch2\u003eFour sizes for common Newtonians\u003c\/h2\u003e\n\u003cp\u003eThe spider is offered in 150 mm, 200 mm, 250 mm and 300 mm sizes to suit different tube diameters, and the kit includes four adaptation parts specifically for Sky-Watcher telescopes so it can drop into the most common tubes without extra machining.\u003c\/p\u003e\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eDetails\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eRB-Focus\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct type\u003c\/td\u003e\n\u003ctd\u003eDouble-vane secondary mirror spider for Newtonian reflectors\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAvailable sizes\u003c\/td\u003e\n\u003ctd\u003e150 mm, 200 mm, 250 mm, 300 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaterials\u003c\/td\u003e\n\u003ctd\u003eCarbon fiber 3000K, stainless steel, brass, carbon fiber FDM PLA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVane width\u003c\/td\u003e\n\u003ctd\u003e0.5 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVane separation\u003c\/td\u003e\n\u003ctd\u003e10 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCollimation points\u003c\/td\u003e\n\u003ctd\u003e4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCollimation screws\u003c\/td\u003e\n\u003ctd\u003eBob knobs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eIn the Box\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e1 x RB-Carbon Fiber Double Spider\u003c\/li\u003e\n\u003cli\u003e4 x Bob knobs\u003c\/li\u003e\n\u003cli\u003e4 x Adaptation parts for Sky-Watcher telescopes\u003c\/li\u003e\n\u003cli\u003e1 x Collimation clutch\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eWarranty\u003c\/h3\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/astronomyplus.com\/pages\/rb-focus-warranty\" target=\"_blank\" rel=\"noopener\"\u003eRB Focus 2-Year Warranty\u003c\/a\u003e\u003c\/p\u003e","brand":"RBFocus","offers":[{"title":"150mm","offer_id":68167151419621,"sku":"RBF-RBFSP001","price":275.0,"currency_code":"CAD","in_stock":true},{"title":"200mm","offer_id":68167151452389,"sku":"RBF-RBFSP002","price":308.0,"currency_code":"CAD","in_stock":true},{"title":"250mm","offer_id":68167151485157,"sku":"RBF-RBFSP003","price":389.0,"currency_code":"CAD","in_stock":true},{"title":"300mm","offer_id":68167151517925,"sku":"RBF-RBFSP004","price":470.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0652\/6245\/2965\/files\/78d234_0716651570b845c39c177499cc0d1e5c_mv2.png?v=1794687520","url":"https:\/\/astronomyplus.com\/products\/rb-focus-carbon-fiber-double-spider","provider":"Astronomy Plus – Telescopes \u0026 Astrophotography Canada","version":"1.0","type":"link"}