The Celestron C80ED refractor is an excellent little telescope. However, owners have long complained of the poor quality of the telescope's stock R&P focuser as its weakest point. Complicating the matter further is the fact that the stock focuser screws into the rear of the telescope tube. Unlike 95% of the other telescopes in the market, the focuser does not bolt to the tube. For those looking to upgrade the focuser, the only alternative until recently was to upgrade to a competing Crayford focuser + adapter costing over $300 - almost the cost of the entire telescope itself!
However, with Agena's new coupling adapter for the Celestron C80ED, you can now attach the very affordable and excellent 86mm GSO Crayford focuser to the C80ED in a few minutes. Installation is easy - just unscrew the stock R&P focuser from the Celestron C80ED tube, screw this adapter into the tube in its place, slide the GSO focuser into this adapter, and bolt it to the adapter using three M4 screws (included with the adapter). The only tool you need to provide is a Philips (cross-head) screwdriver. This upgrade will turn your C80ED telescope into the little beauty it was meant to be.
This adapter will work with GSO's single or dual speed Crayford focusers that have an 86mm flange/base plate (focuser sold separately). It is precision CNC-machined from aluminum and anodized black to match the surface finish of the C80ED tube. The thread pitch is 1mm and the adapter weighs only 1.8oz.
Relative to the stock R&P focuser, the GSO Dual-Speed Crayford/Agena Adapter combination will allow 22mm of additional in-focus travel which is a plus for imaging applications. On the flip side, our configuration will provide 7mm less of back-focus travel compared to the stock focuser but this is easily remedied with an extension tube, if necessary.
If you upgrade your stock C80ED focuser, note that you will loose the built-in finder base on the stock C80ED focuser body when you remove it. To use a finder, you will have to mount a finder bracket directly on the telescope tube, or you can mount it on the GSO focuser body using a special dovetail base (sold separately).
- The vast majority of C80 tubes have a focuser adapter thread pitch of 1mm. A small percentage of C80 tubes have poor threads machined to inexact tolerances, or threads of a slightly different pitch compared to most C80 scopes. It is therefore possible that our adapter may not mate well with your tube, even if the stock focuser has no problems screwing back on. In such cases, we have determined that the problem is with the variance in the tube threads on the C80 tubes, and not with our adapters, each of which is individually tested. To date, four customers have reported this problem (of the 80+ adapters we have sold). If you must return your adapter due to this issue, please note that our standard return policy terms will apply.
- Before ordering this item, please make sure you can unscrew the stock focuser from your telescope tube. It can be very stiff on some C80ED telescopes due to poor machining of threads, and a couple of people have been unable to unscrew the original R&P focuser from their telescope.