In order to supply encoder hardware for the fork mounted Celestron C8 telescope, we need to have information about the right ascension axis center screw hole. Generally we can guess at this information based on the date of manufacture. However, there were great variations and inconsistencies in the manufacturing specifications from inception through 1985. The more information you can provide us, the more likely we will be able to provide the correct main gear for the right ascension axis. Use the following as a guide, remembering that we have seen exceptions to almost every bit of information listed.
If the C8 was manufactured after 1985:
If the C8 was manufactured between 1980 and 1985:
If the C8 was manufactured between 1975 and 1980:
If the C8 was manufactured before 1975:
Please note that the fork mounted C8 is not the same as the Ultima 8, Celestar 8, Celestar 8 Deluxe, Fastar 8 or any German equatorially mounted C8 which all require different hardware.
The C8 Powerstar PEC, with the central right ascension locking knob, needs some special consideration. This telescope was built for encoders but included a flaw in the design. The clock drive movement is not registered by the encoders. This leaves two options with both having drawbacks that must be considered. The first option is to use the Argo Navis Equatorial Table mode since normal R. A. tracking will not be seen by the encoders. The drawback here is that the telescope must be polar aligned for the encoder system to work properly. The second option is to set Argo Navis into Fork Exact align or Fork Rough align mode and turn off the clock drive. With this option, the scope does not need to be polar aligned. The obvious drawback is that the telescope will not be able to track in right ascension.