Posted 30 August 2013 - 11:10 AM
I've had a few opportunities now to test the scope out further. The 1/12 inch shim did not make a difference and even when I move the OTA ever so slightly to make sure that the bearing was not touching the side board, there was still vibration. I guess is just something you have to live with. It can be exacerbated by poor seeing and thermals, but when those two issues are at bay, the tracking is "good". Now Saturn is a bit too low or already has set by the time I am able to observe nowadays, so high power planetary testing can't be done, but I had the Moon at 144x with BV'ers and there was no noticeable vibration.
So overall, I have not quite nailed down the cause. But I will still test with perhaps adding weight to the base or maybe adding to the shims and re-test, in case my first test was flawed and then I'll try whatever else comes to my mind. But I won't worry sooo much about it. While using this scope, I've had a lot of fun. It combines the capability of my XT8i and Nexstar 8SE in one tidy package (those two scopes are gonna hit the selling block!). I find the software/controller on this unit is more user friendly than either the XT8i or the 8SE (though not perfect) and doing the alignment is a snap. Even if I have to turn off the tracking and 'hand-track' with the controller for high-power planetary/double star observing I am ok with that since I am mainly a DSO observer anyways and this scope does well in that regard.