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Solving alignment problems with the Celestron NexStar 8SE — 8 Comments

  1. Instructive reading your experience. I just got a 1 year old SE, and had essentially no alignment problems with it. Fortunately, my handset must have been correct. I don’t know if I ever would have found that. I WILL check it though. The other morning I got up and it was 60 degrees out and crystal clear skies, so just as a test I decided to see how long it would take to set up and see. 5 Minute set up, 2 to align and the alignment was dead on. Could slew to anything. So I have been happy. I have had some difficulty after running the scope for only about 1.5 hours, and I think it is a power issue. The scope would slew to a point, and then keep moving in the az axis. Or it would slew to a point I told it and miss by 6 degrees or so.
    Here is something I did that I will pass on as a FWIW: because I was unsure if it was a power issue or alignment, I did alignment in my home office, simply pointing at a wall. Using auto two star, after I fake pointed it at Mizar, I told it to use Polaris. It slewed the right way, and I said it was OK. Then I test slewed it to some other stars. I could see it was moving appropriately. Then told it to go back to Mizar. It did, and I could verify by looking at the star pointer – pointed at the same point on the wall. I think this could be useful to debug problems, particularly if I were to get a laser pointer attached to the scope. Then, I could move it all over, tell it to go back to the original point, and it should be right on. Much easier than doing it in the cold dark night.

    • First let me say that I both am happy for you and hate you at the same time that your alignment worked perfectly out of the box. 🙂 And for me, the most frustrating part was thinking that’s how it SHOULD have been, but not what I was seeing. Now don’t get me wrong, I still needed to improve some of my other setup to eliminate some margins of error, but honestly if you’re setup is working, don’t change ANYTHING. 🙂

      I’m half certain that if Altitude is inverted, and you go DOWN / RIGHT on the HC, it will work properly. And with a Star Diagonal in the Western Hemisphere, you’re likely seeing it move from upper left quadrant to centre anyway (Down / Right, with inverted setting). I’m only half-certain as UP / RIGHT with NORMAL setting is working for me, and I’m not changing it now!

      Thanks for the debug tip, I like it.

      Paul

  2. I was having the same issue and came across this article from Cloudy Nights.

    Celeston has updated the naming of this setting in the Firmware for version 2.3.7111.

    Here is how to get to the settings from the control pad.
    Menu | Scope Setup | Goto Approach, then Alt Approach and Azm Approach. You select either POSITIVE or NEGATIVE.

    The User Manual does not outline that the alignment to center a star should use the UP and RIGHT approach.

    The snippet below is from the NexStar 6SE User Manual. It states to set the Alt approach to NEGATIVE if you have heavy optical or photographic equipment attached to the back of the scope.

    ===========================================================
    Goto Approach – lets the user define the direction that the telescope will approach when slewing to an object. This allows the user the ability to minimize the affects of backlash.

    For example, if your telescope is back heavy from using heavy optical or photographic accessories attached to the back, you would want to set your altitude approach to the Negative direction. This would ensure that the telescope always approaches an object from the opposite direction as the load pulling on the scope. Similarly, if using the telescope while polar aligned, you would want to set the azimuth approach to the direction that allows the scope to compensate for different load level on the motors and gears when pointing in different parts of the sky.

    To change the goto approach direction, simply choose Goto Approach from the Scope Setup menu, select either Altitude or Azimuth approach, choose positive or negative and press Enter.

    • Thanks Lance, that’s good to know. However, that is not quite the same setting. That setting was there previously too, for similar reasons. Since I rarely have a heavy load, I have mine set to positive, although I know there are some popular experts on Celestrons who say to ALWAYS make it negative.

      In my case, the setting wasn’t so much that (I had minimal backlash, after testing (a previous post), as the way the controller / handset interprets the right/up or left/down directions. My handset was set to reverse up / down so when I was going in the correct order, the scope was not. Hence slippage (or backlash of a different cause and sort). If I had reversed the setting you had, I might not have needed to correct the handset instead. But since I had the right setting for the other for what I was doing, it was easier to correct the handset. 🙂

      Thanks again,

      Paul

  3. I can’t express how much I appreciate finding this info. I’ve recently purchased a used 6se, and thought for sure it was defective. Using the advice found here, I achieved my first “successful” alignment. It would put just about every goto into my eyepiece, and more often than not, very near center.

    • Glad it helps. It’s one of the most satisfying comments to receive, honestly, because I struggled so hard with mine, it’s good to give something back to the community. It seems like 90-95% work perfect out of the box, no issues, and another 5% have some sort of alignment challenge. I just struggled alone with mine having no idea even that the alignment was the problem.

      P.

  4. Wow. Thanks for the “check up and to the right setting”, I never would have thought about that. My heart goes out to you for your troubles. This summer, I helped a lady who was totally befuddled and blamed herself for being stupid. Keeping the situation calm, it took us 2 frustrating nights (turning on-off-reset) to confirm that there was a significant issue. We hoped it was the controller, and Ken from All-Star (in Alberta), swapped it out, and bam! No problems now. When I began helping, I had no experience with hand controllers, but 30+ years as an observer – it is troubling to see how many people have problems with this and that all the flipping controllers and firmware numbers are mount specific. You hit the nail on the head – find yourself a buddy whose experience can defuse the startup issues.

    • Glad your friend was able to have you help her through the troubles! It’s frustrating to know “it’s not right” and yet not be able to reliably narrow down the source of the trouble…

      Paul

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