Hello all:
The recent discussions on PEC curves had led me to some thinking. Do I need to redo the PEC curves when I change payloads? During the winter I primarily use my Celestron C925 Edge HD, especially for galaxy season. And then in the summer I switch to my Explore Scientific ES102mm, for capturing nebulae. As a rough statement I will say the the latter apparatus with counterweights is only half the weight of the former. With the C925 I use an 80mm guide scope with the ES102, a 50mm guide scope. The G11G (w. Gemini 2) I'm using has a one piece worm as far as I know, but I have yet to take it apart in my 3 years of ownership.
Often my best guiding with the C925 is around 0.5 arcsec, while with the ES102 it is about 0.7 arcsec. My assumption was that the smaller guide scope would lead to greater guiding error. But now I am considering whether the total weight could effect the way the gears mesh together, strain on the motors, effects from load balance, etc.
PEMPro is where I get my curves which are then uploaded to the Gemini 2 unit. The best answer would be better safe than sorry and just redo. But other payload combinations are also used and I'm wondering how much weight change makes a difference. Any suggestions or thoughts would be appreciated. I go east heavy in RA, and camera heavy in Dec. Guiding is about the same on either side of the meridian, and best closer to zenith.
Thanks,
John
