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CEM60-ec Meridian Flip

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#1 kisstek

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Posted 13 September 2019 - 02:39 PM

As part of getting all of my AP software reinstalled and getting the new mount configured, I need to get Meridian flips to work. Since I haven't done any on this setup before, I wanted to do it manually first to make sure nothing disastrous happens.

 

I was aimed at the Crescent Nebula last night. It was approaching the Meridian (>84 degrees) so I attempted to initiate a flip manually from APT's "Session Craft" tool. It did the plate solving to figure out what I was pointed and paused the tracking for the preflip settling time. It then started the flip and immediately erred out. According to the APT log, the flip took 1 second, which is less than the 15 second safety minimum.

 

2019/09/12 20:38:01 (UT 2019/09/13 03:38:01) Op PointCraft: Image solved in 7s using 269 stars
2019/09/12 20:38:01 (UT 2019/09/13 03:38:01) Op PointCraft: Detected FOV size (arc-minutes) - 37.26 x 28.17
2019/09/12 20:38:01 (UT 2019/09/13 03:38:01) Op Target locked before flip. RA=20:11:59.22, Dec=38:21:01.92.
2019/09/12 20:38:01 (UT 2019/09/13 03:38:01) Op Stopping PHD2 Guiding.
2019/09/12 20:38:02 (UT 2019/09/13 03:38:02) Op Tracking disabled.
2019/09/12 20:38:02 (UT 2019/09/13 03:38:02) DBG PHD2 Guiding Stopped.
2019/09/12 20:38:03 (UT 2019/09/13 03:38:03) Op Starting flip via GoTo.
2019/09/12 20:38:04 (UT 2019/09/13 03:38:04) Op Flip move finished.
2019/09/12 20:38:04 (UT 2019/09/13 03:38:04) OpErr Flip move finished for 1s, it is faster than the defined safety limit of 15s.
2019/09/12 20:38:04 (UT 2019/09/13 03:38:04) OpErr Can't complete an Automated Meridian Flip! Stopping all actions...
2019/09/12 20:38:04 (UT 2019/09/13 03:38:04) Op Tracking disabled.
2019/09/12 20:38:04 (UT 2019/09/13 03:38:04) Op Stopping the imaging plan (if any is running)...
2019/09/12 20:38:04 (UT 2019/09/13 03:38:04) Op Stopping...
2019/09/12 20:38:04 (UT 2019/09/13 03:38:04) Op Stopped
2019/09/12 20:38:04 (UT 2019/09/13 03:38:04) Op Stopped
2019/09/12 20:38:04 (UT 2019/09/13 03:38:04) Op Settling after flip move.

 

The mount didn't move at all! I have no idea why not. My old Celestron AVX just worked when it came to flips.

 

So I went inside to research what other people did when they had this issue. While search, APT decided to do an automatic flip. It went thru the same process but this time, the mount actually flipped! (APT then bitched that the mount didn't settle fast enough and turned tracking off anyway. But that's a different problem that I'll track down next flip. I forgot to save the log file again after that semi successful flip.)

 

Anybody have an idea what I have configured wrong? I don't remember what I set the HC settings to for the flip. I probably left it at the default as the manual is not very informative on the flip options.


Edited by kisstek, 13 September 2019 - 02:40 PM.


#2 gotak

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Posted 13 September 2019 - 03:28 PM

Set HC to flip 2 minutes pass. That's how you get it to work with SGP. Otherwise they can race each other the external flip and internal flip command.


Edited by gotak, 13 September 2019 - 03:28 PM.


#3 gotak

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Posted 13 September 2019 - 03:36 PM

Board replacement achieved nothing. Well now what? They don't seem to have an answer.



#4 OldManSky

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Posted 13 September 2019 - 06:40 PM

It didn’t move probably because it actually hadn’t passed the meridian yet. If the target coordinates are still on the same side of the meridian as you’re already at, the mount won’t move when a goto is issued.

Can you set the pause to wait for the target to actually cross the meridian to a couple of minutes longer?

That should do it.


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#5 kisstek

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Posted 13 September 2019 - 07:29 PM

It didn’t move probably because it actually hadn’t passed the meridian yet. If the target coordinates are still on the same side of the meridian as you’re already at, the mount won’t move when a goto is issued.

Can you set the pause to wait for the target to actually cross the meridian to a couple of minutes longer?

That should do it.

Argh! That's dumb! If it'll do the flip up to an hour or so after passing the Meridian, it should be willing to do it up to an hour before the Meridian. Or at least in the world according to me! :-)


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#6 Tom K

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Posted 13 September 2019 - 10:44 PM

For my CEM60 I make sure that SGP is set to flip before the mount is set to flip and things work out OK for me.  I have not tried to flip pre-meridian but you are right it should not make much difference, but I can only control the things I can control.   The miracle of autofocus and automated meridian flips has been a game changer in this hobby for me - I can get lots of data and also some sleep!   Of course, I used to manually guide a Meade 2120 LX5 with a film camera piggybacked on it well over 30 years ago so the things we complain about today were just crazy dreams back then.   I can't imagine what imagers 30 years from now will have at their disposal.


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#7 kisstek

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Posted 13 September 2019 - 11:55 PM

After getting setup tonight, it was eight minutes before the auto flip. So I just waited for it to do it's thing and then clean up after it. An of course, it succeeded! After the flip, it was off by 5500 pixels, which is like 2700 arc seconds. So not even close. But it took the CEM60 two hops to get with 12 pixels of the original center.

 

The lack of repeatability of this hobby/obsession drives me nuts sometimes! :-)

 

Anyway, for tonight, I'm off wasting scope time collecting O3 and S2 images of the Crescent Nebula, the bane of my existence! :-) (Trying to image the Crescent Nebula is what got me started down path to the dark side 14 months ago.)


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#8 Der_Pit

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Posted 14 September 2019 - 09:41 AM

Argh! That's dumb! If it'll do the flip up to an hour or so after passing the Meridian, it should be willing to do it up to an hour before the Meridian. Or at least in the world according to me! :-)

The issue is that there is no command to flip the mount.  You just tell it 'go to this coordinates'. Also, your allowed range before and after meridian doesn't have to be symmetric!

 

BTW, not sure if it had been mentioned before - the mount would do its own flip when reaching the specified (in FW/HC) limit.  So make sure you set this higher than the limit in the software, else the mount will just flip by itself during observations....




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