Astronomy telescopes, Dobsonian telescope kits, primary mirrors, elliptical secondary mirrors, (Also WHEN AVAILABLE: mirror holders, spiders, lenses, telescope parts, astronomy accessories, eyepieces, filters, diagonals, finder scopes, Telrads, photo adaptors, close-out specials) Exclusively using Coulter Optical ® optics. After researching several possible sources for a primary mirror, I decided to order an f/5 12.5 inch mirror from Discovery Optics. Yes, you can use the kit on other telescopes as well.--$45 for 2 "string" kit. The company has a reputation for excellent optics, and it was neither the most expensive, nor the least. If you have a question or need a spider not listed, send your specs. String Telescope Component Kit. The threaded stainless steel vane tips (#10-32) are solidly TIG welded to the vanes, making this the strongest spider on the market. Shop with confidence. This isn't my idea. Parts List (the full story of acquiring the parts) The primary, secondary, spider and secondary holder—Discovery Optics. Instead of using single-point swivel bolts, like other spider vanes, VSI uses a full-length slotted bar, which is bolted at both ends of the vane to prevent this swivel motion. FIGURE 108: Visual appearance of a bright star without spider effect (a), with three-vane spider effect (b), and four-vane spider effect - the two most common spider forms - (c).The effect is noticeable mainly on objects of high telescopic brightness. Spider head/vane/hub (3"Lx2"D) 3/4" SS shaft, up to 12", Item SH2: $795 ... At right is a close-up picture of the the end of each vane, where it attaches to your telescope's tube assembly. This spider is easy to make, it's inexpensive, the vanes are very thin yet extremely strong, and it's light weight, too. Custom-made and sized for your tube, utilizing high-tensile steel TIG welded at the hub, giving the vanes extra stability. Convert your parallel strut telescope into a virtual truss design (see here for a complete discussion), Kit includes everything you'll need for your DobSTUFF telescope. Clearance - Parts & Accessories; Clearance - Telescopes; Clearance - Binoculars; Sales & Special Offers; Baader 2020 Christmas Sale; Pentax Eyepiece Sale; QHYCCD 2020 Holiday Sale; Vixen Crazy November Sale; ZWO Holiday Sale; Home; Brands; New Products; Articles / Guides; Clearance / Sales. Astrosystems rigid 4-vane Spider and Secondary Mirror Holder with four-point collimation adjustment. Observatory Curved Four Vane Telescope Spider (recommended for 16 to 24 inch tubes with secondarys less than 5 inch) Extreme Curved Vane Telescope Spider (recommended for 20 to 36 inch tubes with secondarys less than 6 inch)* * Sale * * Pyrex Secondary Mirrors. Find great deals on eBay for telescope spider. I don't know who came up with this idea, but I first saw it at the Chabot Telescope Maker's workshop in … I need to give credit where credit is due.