Greetings fellow LX850 weight lifters!
I have been the proud owner of the LX850 mount now for almost seven months. During that time I have learned intensely and have literally gone through everything in the manual several times, at a minimum. I still have an intermittant problem of some significance. First, I am probably an advanced intermediate astroimager having several serious and very productive years on an Orion Atlas with a 120mm refractor.
After completing the entire initial (one star) and then drift alignment process, then PEC training, and finally the Automatic Rate Calculation, I typically get noticeably elongated stars on a ten minute exposure! The stars are consistently elongated E-W.
Yes, I have checked all adjustments and connections to ensure there is no line drag or optic train shift. The scope and equipment is balanced in all directions. I am using the StarLock on its side-saddleplate mount, the telescope is a Celestron 1100 EDGE HD with a Celestron 0.7 reducer, and the camera is an SBIG 8300 STF-M with 8 position filter wheel.
There have been times when the alignment has been nearly perfect with good results but, for example, last night after going through the entire time-consuming process, I had some of the most elongated stars I have ever seen on a GEM. Before imaging, I went through the drift alignment sequence twice and the hand-paddle message was "no-turns needed" on both axises. On the nights I have gotten good results, i have needed to go back and re-do the drift alignment manually. On those nights the elevation setting was in need of noticeable adjustment. Last night as I refocused after Starlock drift alignment, I noted the focus star (at 400% enlargement) was slightly drifting upwards during the focus process.
I presume that the elevation adjustment is the issue because of the E-W (RA) drift on a target just north of the equator. Notably, the difference between the one-star alignment and drift alignment in elevation settings was quite significant. After drift alignment, the scope would goto a star within an error of less than 5 arc-min using Sky-X near the equator, but had a significant error if I re-initiate setup on Polaris. The error when initializing setup on Polaris is around one degree, requiring use of the spotter scope to see Polaris.
Any help would be greatly appreciated, and thanks in advance!