[rcheshire (Rowland)]

Thanks Alistair and Brett.

I'm feeling out the options and really appreciate the feedback. Thanks again Alistair for comprehensive reply.

Other than the engineering difficulty of accurately aligning/offsetting the encoder lines the rest of the double sided encoder is not too difficult, even for me. I will post a working test sample out of interest - Christmas is upon us. A professionally made disk would be best. Some Chinese suppliers do small quantities. I saw a define your own design option as well.

In context. My mount is 15 years old and from what I can see and confidently turn my hand to, is not given to significant modification and requires either hollow shaft encoders such as those supplied by Takahashi or a geared assembly, a'la Argo Navis.

I understand the various tracking rates and accept the potential limitation of a siderial only system. Interestingly, the mount has potentiometers to adjust for other tracking rates - trial and error.

I am more inclined toward the guiding solution, but really want to simplify things - an encoder system to improve tracking is the minimalist option. Having exhausted all reasonable possibilities, I will move onto Alistair's recommendation of guiding.

Seriously, if not for the mental and creative stimulation, I would probably buy myself an ieq45-GT, all singing and dancing accurate little beast and be done with it. It's mostly cloudy down this way, so it wouldn't get much use anyway. With the Tak's raw tracking accuracy, I could get away with nothing but that.

I have gone from interfacing with a PC for tracking, to a closed loop system to iron out tracking errors (which depending on what you read is good or bad) to guiding, which is a completely new paradigm. Standby for more dumb questions.