A 12-inch Newton that you regularly transport should also be aligned regularly. Looking for the correct bolt behind the tube with a wrench or screwdriver in the dark is not convenient. These adjustment screws for a 12-inch Newton from Bob\u2019s Knobs have a large button, so you can adjust the main mirror with your fingers.<\/p>\n\n\n\n
They replace the screws of the main mirror cell. Many large Dobson telescopes<\/a> have such a Newton tube, but the structure of the mirror cell differs merk per model. Therefore, check beforehand whether this set fits your telescope.<\/p>\n\n\n\n Replace the screws one by one so that the mirror does not shift. Then check the collimation with a collimation tip or a Hotech point laser collimator<\/a>. Keep turning just a little bit and look again in between.<\/p>\n\n\n\n If you have a Sky-Watcher Newton, there is also one Set for the Sky-Watcher spotting scope<\/a>. For a 10 inch Newton there is one set for the 10 inch head mirror<\/a>.<\/p>","protected":false},"excerpt":{"rendered":" Bob\u2019s Knobs for the main mirror cell of a 12-inch Newton, which allows you to align the mirror without tools.<\/p>","protected":false},"featured_media":112858,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false},"product_brand":[1559],"product_cat":[56,3091],"product_tag":[],"class_list":["post-112859","product","type-product","status-publish","has-post-thumbnail","product_brand-bobs-knobs","product_cat-telescoop-accessoires","product_cat-telescoop-onderdelen","first","instock","taxable","shipping-taxable","purchasable","product-type-simple"],"bundled_by":[],"bundle_stock_status":"instock","bundle_stock_quantity":null,"bundle_virtual":false,"bundle_layout":"","bundle_add_to_cart_form_location":"","bundle_editable_in_cart":false,"bundle_sold_individually_context":"","bundle_item_grouping":"","bundle_min_size":"","bundle_max_size":"","bundle_price":[],"bundled_items":[],"bundle_sell_ids":[],"acf":[],"jetpack_sharing_enabled":true,"jetpack-related-posts":[{"id":112857,"url":"https:\/\/www.telescoop.nl\/en\/afstelschroeven-voor-de-hoofdspiegel-van-een-10-inch-newton-bobs-knobs\/","url_meta":{"origin":112859,"position":0},"title":"Adjusting screws for the main mirror of a 10 inch Newton | Bob\u2019s Knobs","author":"Info telescoop","date":"09-10-2026","format":false,"excerpt":"Large adjustment buttons from Bob's Knobs for the main mirror cell of a 10-inch Newton. Alignment then takes place by hand.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/55356_1.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/55356_1.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/55356_1.jpg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":30386,"url":"https:\/\/www.telescoop.nl\/en\/bobs-knobs-afstelschroeven-voor-skywatcher-newton-secundaire-spiegel\/","url_meta":{"origin":112859,"position":1},"title":"Bob's Knobs Adjusting Screws for SkyWatcher Newton Secondary Mirror","author":"","date":"08-10-2025","format":false,"excerpt":"Bob's Knobs for the secondary mirror of Sky-Watcher Newtonians: collimating without a screwdriver above the open tube.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"Bob\u2019s Knobs Afstelschroeven voor SkyWatcher Newton Secundaire Spiegel","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-Kartelschroeven-voor-vangspiegel-van-Skywatcher-Newton-tot-12-.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-Kartelschroeven-voor-vangspiegel-van-Skywatcher-Newton-tot-12-.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-Kartelschroeven-voor-vangspiegel-van-Skywatcher-Newton-tot-12-.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-Kartelschroeven-voor-vangspiegel-van-Skywatcher-Newton-tot-12-.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-Kartelschroeven-voor-vangspiegel-van-Skywatcher-Newton-tot-12-.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-Kartelschroeven-voor-vangspiegel-van-Skywatcher-Newton-tot-12-.jpg?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":30381,"url":"https:\/\/www.telescoop.nl\/en\/bobs-knobs-springveren-voor-newton\/","url_meta":{"origin":112859,"position":2},"title":"Bob's Knobs springs for Newton","author":"","date":"08-10-2025","format":false,"excerpt":"Bob's Knobs collimation springs for 8 to 10 [Note: the original says 8 tot 12, so use 8 to 12] inch Newtonians: higher spring tension holds the primary mirror in place so that collimation is maintained.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"Bob\u2019s Knobs springveren voor Newton ","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-Springveren-voor-hoofdspiegel-van-Newton-telescopen-van-8-tot-12-.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-Springveren-voor-hoofdspiegel-van-Newton-telescopen-van-8-tot-12-.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-Springveren-voor-hoofdspiegel-van-Newton-telescopen-van-8-tot-12-.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-Springveren-voor-hoofdspiegel-van-Newton-telescopen-van-8-tot-12-.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-Springveren-voor-hoofdspiegel-van-Newton-telescopen-van-8-tot-12-.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-Springveren-voor-hoofdspiegel-van-Newton-telescopen-van-8-tot-12-.jpg?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":112897,"url":"https:\/\/www.telescoop.nl\/en\/afstelschroeven-voor-de-hoofdspiegel-van-de-vixen-r200ss-bobs-knobs\/","url_meta":{"origin":112859,"position":3},"title":"Adjusting screws for the main mirror of the Vixen R200SS | Bob\u2019s Knobs","author":"Info telescoop","date":"09-10-2026","format":false,"excerpt":"Bob's Knobs for the main mirror cell of the Vixen R200SS. This allows you to adjust the mirror manually, even when the telescope is already outside.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/58103_1.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/58103_1.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2026\/10\/58103_1.jpg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":30378,"url":"https:\/\/www.telescoop.nl\/en\/bobs-knobs-afstelschroeven-voor-telrad-finder\/","url_meta":{"origin":112859,"position":4},"title":"Bob's Knobs Adjusting Screws for Telrad Finder","author":"Info telescoop","date":"08-10-2025","format":false,"excerpt":"Bob\u2019s Knobs for the Telrad: three stainless steel thumbscrews that allow you to precisely align the finder scope without tools.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"Bob\u2019s Knobs Afstelschroeven voor Telrad Finder","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-Kartelschroeven-voor-Telrad-zoeker.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-Kartelschroeven-voor-Telrad-zoeker.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-Kartelschroeven-voor-Telrad-zoeker.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-Kartelschroeven-voor-Telrad-zoeker.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-Kartelschroeven-voor-Telrad-zoeker.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-Kartelschroeven-voor-Telrad-zoeker.jpg?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":30398,"url":"https:\/\/www.telescoop.nl\/en\/bobs-knobs-afstelschroeven-voor-celestron-sct-11-f-10-metric\/","url_meta":{"origin":112859,"position":5},"title":"Bob's Knobs Adjusting Screws for Celestron SCT 11\u2033 f\/10 Metric","author":"","date":"08-10-2025","format":false,"excerpt":"Bob's Knobs for the Celestron 11-inch f\/10 SCT Metric: stainless steel thumb screws for secure, tool-free secondary mirror collimation.","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"Bob\u2019s Knobs Afstelschroeven voor Celestron SCT 11\" f\/10 Metric","src":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-SCT-11-f-10-metric.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-SCT-11-f-10-metric.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-SCT-11-f-10-metric.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-SCT-11-f-10-metric.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-SCT-11-f-10-metric.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/www.telescoop.nl\/wp-content\/uploads\/2025\/10\/Bobs-Knobs-SCT-11-f-10-metric.jpg?resize=1400%2C800&ssl=1 4x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product\/112859","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/comments?post=112859"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media\/112858"}],"wp:attachment":[{"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/media?parent=112859"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_brand?post=112859"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_cat?post=112859"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.telescoop.nl\/en\/wp-json\/wp\/v2\/product_tag?post=112859"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}