Jump to content


Photo

Heq5 Pro (sirius EQ-G) meridian flip question.

  • Please log in to reply
6 replies to this topic

#1 neptun2

neptun2

    Viking 1

  • -----
  • Posts: 858
  • Joined: 04 Mar 2007
  • Loc: Bulgaria

Posted 11 June 2009 - 04:34 AM

Hi all. I will recently receive my heq5 upgrade kit to make my mount goto and i wonder what is the situation with meridian flip and the hand controller. I read that if i use eqmod i can set limits which concern the meridian flip but could not find any information about the hand controller. I read the user manual for synscan and did not see such options. Based on the information that i found i suspect that if i am tracking an object and it passes the meridian the mount will not flip and will continue to track until it reaches hard limit or crashes into the pier. But if i am looking object at one side of the meridian and then i initiate goto to object on the other side of meridian then the mount will automatically flip. Is this correct?

#2 Charlie Hein

Charlie Hein

    Voyager 1

  • *****
  • Administrators
  • Posts: 12308
  • Joined: 02 Nov 2003
  • Loc: 26.06.08N, +80.23.08W

Posted 11 June 2009 - 06:18 AM

Yes this is correct.

#3 neptun2

neptun2

    Viking 1

  • -----
  • Posts: 858
  • Joined: 04 Mar 2007
  • Loc: Bulgaria

Posted 11 June 2009 - 08:47 AM

Ok Charlie thank you for the information. Clear skies to all.

#4 Zebra24601

Zebra24601

    Hubble

  • *****
  • Posts: 16430
  • Joined: 09 Oct 2005
  • Loc: San Gabriel Valley, CA 91770

Posted 11 June 2009 - 06:48 PM

On the other hand, I was looking at something far to the south and right on the meridian a few weeks ago. My Sirius went into a crazy loop. First it tried to frame the object one way. Then it decided that, no, it had better approach it from the other way, so it slewed back around and did the flip. Then it decided, no, let's try from the other side, again. Another slew and another flip. I think around then, I just shut the thing down. Not sure how long it would have kept trying before it picked one side or the other.

#5 Charlie Hein

Charlie Hein

    Voyager 1

  • *****
  • Administrators
  • Posts: 12308
  • Joined: 02 Nov 2003
  • Loc: 26.06.08N, +80.23.08W

Posted 11 June 2009 - 11:20 PM

Never experienced this personally. Can't imagine what could have caused this to happen. Can you provide the exact date, time, object and location where this happened so that we can try to reproduce this? I'm certain that the software developers would really want to know about this so they can fix it.

#6 groz

groz

    Surveyor 1

  • *****
  • Posts: 1954
  • Joined: 14 Mar 2007
  • Loc: Campbell River, BC

Posted 11 June 2009 - 11:49 PM

Probably an alignment issue. Set up, get your polar align off a bit, and a bunch of cone error. So, the hc calculates where object _should_ be, slews to the 'before taking up backlash' position and prepares to add in the cone error while taking up backlash, realizes it's on the wrong side of the meridian, slews to the other side. Depending on the order of events inside the firmware, this can turn into a 'lather rinse repeat' exercise until the object moves away from the meridian by more than your alignment / cone errors.

I've seen a similar sort of thing, on something within a half degree of the meridian. Slew in from one side, then change it's mind and slew in the other way. Sad part, I was going to a bright star to sync, and then the slew to my actual target, well, back across the meridian again. I learned my lesson, always pick a sync star on the same side of meridian as the target.

#7 Charlie Hein

Charlie Hein

    Voyager 1

  • *****
  • Administrators
  • Posts: 12308
  • Joined: 02 Nov 2003
  • Loc: 26.06.08N, +80.23.08W

Posted 12 June 2009 - 07:19 AM

Probably an alignment issue. Set up, get your polar align off a bit, and a bunch of cone error. So, the hc calculates where object _should_ be, slews to the 'before taking up backlash' position and prepares to add in the cone error while taking up backlash, realizes it's on the wrong side of the meridian, slews to the other side. Depending on the order of events inside the firmware, this can turn into a 'lather rinse repeat' exercise until the object moves away from the meridian by more than your alignment / cone errors.

I've seen a similar sort of thing, on something within a half degree of the meridian. Slew in from one side, then change it's mind and slew in the other way. Sad part, I was going to a bright star to sync, and then the slew to my actual target, well, back across the meridian again. I learned my lesson, always pick a sync star on the same side of meridian as the target.


Makes sense. I would always try to work things so that my last star was as near my target as possible.






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics