West Veil Nebula (NGC6960) and Equipment Tuning

My objectives for this session were to try Drift Alignment without Polemaster, and to get about 2.5 hours on Western Veil Nebula.

After getting the best guiding that I thought that I could get after tinkering for about an hour, I got a really bad final slew to the target. I was really tired, so I shut everything down and went inside. I was in bed by 2330, and slept 10 hours. Wow!

I tried bypassing PoleMaster and going straight to Drift Alignment. I found that I was not able to start Drift Alignment any sooner than I would have started with Polemaster.

Keep in mind that I had the scope off of the mount, and the mount off of the tripod for a backlash adjustment during the day yesterday, so my starting alignment was probably off more than from settling alone. In the az phase of the drift alignment, the trend line started very steeply downward, and after something approaching ten adjustment attempts, it still wasn’t at zero. Thinking that after that many attempts that something must be very wrong, I resorted to Polemaster to get a read on the situation. Polemaster showed me that I had reached an alignment that was actually very close on azimuth and even though I hadn’t touched elevation, it was close as well. I trued up NCP in Polemaster and went back to PHD Drift Alignment. This time I found a better trend line in both az and el, and a 1.9’ polar alignment error, so I accepted that and moved on.

I next did a calibration run, and got a squigglier Dec leg than I did the night before, and orthogonality was way off. I tried a guiding assistant run, and found the same 1.9’ PAE, and that backlash was 1850ms, up 500ms from the night before, even after what I had hoped would be a better adjustment. But even that amount of backlash is reasonable, so I am going to stick with the present adjustment though this new moon period, as the period is already upon us.

Deciding not to adjust anything else, I rough slewed (without a star alignment) to Western Veil Nebula just to see what my guiding looked like. The Dec line was not too noisy (not varying too much) and was staying within .5” with almost no guide impulses, which is really good. Ra, was just outside of the 1’ bounds, but with lots of guide impulses in both directions. I adjusted the counterweights outward to increase the balance toward the east side, and the guiding impulses settled down just a little.

It is worth noting that I am beginning to discern more and more from watching what is going on in the charts that PHD provides. I am certain that I have a lot more to learn.

I then decided to start the NINA sequence, which I thought that I had set up for a final slew and plate solve on Western Veil Nebula. The telescope was already pointing at or close to the target when I initiated the slew, but the telescope took off to the west until I stopped it near the western safety limit. I have no idea why this happened.


Since Polemaster takes just five minutes ad makes certain that I have a good starting point for Drift Alignment, and since I cannot start drift alignment any earlier than I can start a Polemaster alignment, I am going to keep Polemaster in my workplan. Last night I could have done Polemaster then Drift Alignment in way less time than I spent on Drift Alignment alone. So starting with Polemaster then tweaking in Drift Alignment like I did the night before seems to be the way to go.

Last night, and even right here in the clear light of day, I am not clear on the right order to do drift alignment, calibration and a guiding assistant run to get the best result, so I want to get clear on that topic.

And finally, I need to work with the mount, especially with east-heavy balancing to get the Ra axis to calm down.

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