RE: [ap-gto] Re: a continue Resync, why?


Oct 30, 2014

 


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#45666 Oct 30, 2014

I use a new AP GTO 1100 mount that is well polar aligned; when i point an object with SkyX Pro i see ��red circular references (named telrad finder?) ��around the object; when i unpark the mount and execute the slew command the yellow circular reference of the scope meets the red circular references and they are matched; but ��during the action of a guiding camera the 2 circular references (yellow and red) are always more mismatched ��and away from each other how more is the time of the guiding action. So after some hours of imaging and guiding i have to syncronize the scope; i have to do the same syncronization also without guiding because the object ��go out of the field of camera after 3-4 hours but the 2 circular references (yellow and red) are always matched; i syncronize the scope manually with the jog command to Est (20-30 arcminuts in 3-4 hours). Can you explain to me the reason?



Carmine



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#45667 Oct 30, 2014

HI Carmine,



In addition to polar alignment errors tracking and pointing errors can also come from telescope and camera flexure, mirror flop, refraction, etc.



-Ray Gralak

Author of Astro-Physics Command Center (APCC)

Author of PEMPro: www.ccdware.com

Author of Astro-Physics V2 ASCOM Driver: www.gralak.com/apdriver

Author of PulseGuide: www.pulseguide.com

Author of Sigma: www.gralak.com/sigma

> -----Original Message-----

> From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com]

> Sent: Thursday, October 30, 2014 8:26 AM

> To: ap-gto@yahoogroups.com

> Subject: [ap-gto] a continue Resync, why?

>

>

>

> I use a new AP GTO 1100 mount that is well polar aligned; when i point an object with SkyX Pro i see red circular

> references (named telrad finder?) around the object; when i unpark the mount and execute the slew command the

> yellow circular reference of the scope meets the red circular references and they are matched; but during the action

> of a guiding camera the 2 circular references (yellow and red) are always more mismatched and away from each

> other how more is the time of the guiding action. So after some hours of imaging and guiding i have to syncronize the

> scope; i have to do the same syncronization also without guiding because the object go out of the field of camera

> after 3-4 hours but the 2 circular references (yellow and red) are always matched; i syncronize the scope manually

> with the jog command to Est (20-30 arcminuts in 3-4 hours). Can you explain to me the reason? /p>

>

>

> Carmine

>

>

>

>

>



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#45668 Oct 30, 2014

No in my case it is not a problem of flexure because it is continue and regular and only in AR direction; it seems a problem of clock different from the mount and the software or a problem of stars pointing model. But i am not able to verify.Any suggest are useful to avoid a continue annoying resync.



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#45669 Oct 30, 2014

Tell us more about your scope and all devices in the optical path.I vote for flexure too.

Christopher Erickson

Consulting Engineer

Summit Kinetics

Waikoloa, Hi 96738On Oct 30, 2014 10:19 AM, "gc.iaffaldano@... [ap-gto]" ap-gto@yahoogroups.com> wrote:

No in my case it is not a problem of flexure because it is continue and regular and only in AR direction; it seems a problem of clock different from the mount and the software or a problem of stars pointing model. But i am not able to verify.Any suggest are useful to avoid a continue annoying resync.



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#45671 Oct 30, 2014

My scope is an RC GSO 10" with an Apogee F9 and Lodestar as guiding camera:��setup (iagica) | AstroBin

setup (iagica) | AstroBin AstroBin is an image hosting website specifically targeted to astrophotographers: it's the first and the last place where you need to upload yo...



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#45672 Oct 30, 2014

Carmine,



With all that weight hanging off the end of your scope what makes you think there is no flexure?



-Ray Gralak

Author of Astro-Physics Command Center (APCC)

Author of PEMPro: www.ccdware.com

Author of Astro-Physics V2 ASCOM Driver: www.gralak.com/apdriver

Author of PulseGuide: www.pulseguide.com

Author of Sigma: www.gralak.com/sigma



> -----Original Message-----

> From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com]

> Sent: Thursday, October 30, 2014 10:51 AM

> To: ap-gto@yahoogroups.com

> Subject: RE: [ap-gto] a continue Resync, why?

>

>

>

> My scope is an RC GSO 10" with an Apogee F9 and Lodestar as guiding camera: setup (iagica) | AstroBin

> www.astrobin.com/122107/>

> image www.astrobin.com/122107/>

> setup (iagica) | AstroBin www.astrobin.com/122107/>

> AstroBin is an image hosting website specifically targeted to astrophotographers: it's the first and the last place where

> you need to upload yo...

> View on www.astrobin.com www.astrobin.com/122107/>

> Preview by Yahoo

>

>

>

> here some image with the AP mount:

>

> Ngc 6946 (iagica) | AstroBin www.astrobin.com/123188/C/>

> IC 63 e Gamma Cassopeia (iagica) | AstroBin www.astrobin.com/123377/C/>

> Ngc 7023 Iris Nebula (iagica) | AstroBin www.astrobin.com/132691/>

>

> IC 1805 Lumi nanza (iagica) | AstroBin www.astrobin.com/131751/>

>

> Is it enough?

>

> image ---Links-Are-Forbidden--- /www.astrobin.com/131751/>

> IC 1805 Luminanza (iagica) | AstroBin www.astrobin.com/131751/>

> AstroBin is an image hosting website specifically targeted to astrophotographers: it's the first and the last place where

> you need to upload yo...

> View on www.astrobin.com www.astrobin.com/131751/>

> Preview by Yahoo

>

>

>

>

> image www.astrobin.com/132691/>

> Ngc 7023 Iris Nebula (iagica) | AstroBin www.astrobin.com/132691/>

> AstroBin is an image hosting website specifically targeted to astrophotographers: it's the first and the last place where

> you need to upload yo...

> View on www.astrobin.com www.astrobin.com/132691/>

> Preview by Yahoo

>

>

>

>

>

> image www.astrobin.com/123377/C/>

> IC 63 e Gamma Cassopeia (iagica) | AstroBin www.astrobin.com/123377/C/>

> AstroBin is an image hosting website specifically targeted to astrophotographers: it's the first and the last place where

> you need to upload yo...

> View on www.astrobin.com www.astrobin.com/123377/C/>

> Preview by Yahoo

>

>

>

>

>

> image www.astrobin.com/123188/C/>

> Ngc 6946 (iagica) | AstroBin www.astrobin.com/123188/C/>

> AstroBin is an image hosting website specifically targeted to astrophotographers: it's the first and the last place where

> you need to upload yo...

> View on www.astrobin.com www.astrobin.com/123188/C/>

> Preview by Yahoo

>

>

>

>

>

>







----------------------------

#45673 Oct 30, 2014

Is there any chance that you have not set the mount to sidereal tracking? It sounds like you are simply tracking at some other rate since you report that the mount is fast in RA (I figure that's what AR means.)Anyway, just a thought to check out -looks like you have pretty nice gear and so flexure of 20 arc minutes in three hours just doesn't add up.Rgrds-Ross



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#45675 Oct 30, 2014

This is reasonable; yes RA is AR, sorry; i have not a precise measure of the drift but i ��am pretty sure that is steady. I use always the right button of the log to do the resync wheter if the scope is at East both is at West of meridian.



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#45677 Oct 30, 2014

The sky itself has that much error simply from atmospheric refraction, depending how low he is shooting.��When you do polar drift alignment using Dec drift only, then RA drift can be quite large. That is another source of error. You think that because you have done drift alignment, that you eliminate drift in both axes, but this is not the case. Classic drift alignment only reduces Dec drift, and results in fairly large amount of RA drift.��Rolando





-----Original Message-----

From: rgsalinger@... [ap-gto] ap-gto@yahoogroups.com>

To: ap-gto ap-gto@yahoogroups.com>

Sent: Thu, Oct 30, 2014 1:05 pm

Subject: [ap-gto] Re: a continue Resync, why?





Is there any chance that you have not set the mount to sidereal tracking? It sounds like you are simply tracking at some other rate since you report that the mount is fast in RA (I figure that's what AR means.)Anyway, just a thought to check out -looks like you have pretty nice gear and so flexure of 20 arc minutes in three hours just doesn't add up.Rgrds-Ross



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#45679 Oct 30, 2014

20 arc minutes of drift over 3 hours from refraction? Am I reading the OP wrong?Rgrds-Ross ��From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com] Sent: Thursday, October 30, 2014 12:25 PMTo: ap-gto@yahoogroups.comSubject: Re: [ap-gto] Re: a continue Resync, why?



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#45680 Oct 30, 2014

Stars slow down at the horizon. Almost 1/2 degree off between horizon and 45 degrees up, no?

Rolando



-----Original Message-----

From: Ross Salinger rgsalinger@... [ap-gto] ap-gto@yahoogroups.com>

To: ap-gto ap-gto@yahoogroups.com>

Sent: Thu, Oct 30, 2014 3:03 pm

Subject: RE: [ap-gto] Re: a continue Resync, why?





20 arc minutes of drift over 3 hours from refraction? Am I reading the OP wrong?Rgrds-Ross��From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com]

Sent: Thursday, October 30, 2014 12:25 PM

To: ap-gto@yahoogroups.com

Subject: Re: [ap-gto] Re: a continue Resync, why?



----------------------------

#45681 Oct 30, 2014

Carmine,



Gravity causes flexure on EVERY telescope. Unless you are in space there will be flexure in your scope cause by gravity, no matter how solid you think it is.



-Ray Gralak

Author of Astro-Physics Command Center (APCC)

Author of PEMPro: www.ccdware.com

Author of Astro-Physics V2 ASCOM Driver: www.gralak.com/apdriver

Author of PulseGuide: www.pulseguide.com

Author of Sigma: www.gralak.com/sigma



> -----Original Message-----

> From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com]

> Sent: Thursday, October 30, 2014 12:18 PM

> To: ap-gto@yahoogroups.com

> Subject: RE: [ap-gto] a continue Resync, why?

>

>

>

> I do not mean that you insult my intelligence but certainly the quality of my accessories , yes; i use the same setup

> from many years with another mount of quality and never any flexure of this type.

>

>



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#45683 Oct 30, 2014

This is more reasonable because the ascom tells ��me that the mount is in sideral tracking and i believe to the mount like i believe that my accessories have no flexure of this type; but if PolarAlignMax does a not perfect alignment because it uses only DEC moves what software i have to use to do a good alignment? Has the AP software a routine to do a more precise alignment? in the past i have used for my previuos mount a proprietary software of alignment to 3 stars or more ( alignment to model stars) that can avoid any errors and conic error too; but for AP that has a better mechanical funcionality what i have to do?



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#45686 Oct 30, 2014

There are many methods of polar alignment. None of them will give you perfect tracking or perfect pointing, but they should all provide very low alignment and tracking��errors. Which one to use depends whether you have a portable setup, or you have a permanent setup. ��My favorite for quick alignment for a portable mount is to use a star near the zenith to adjust the mount's altitude axis, and a star in the east or west to adjust the azimuth axis. It is quite accurate and results in very close pointing and quite good tracking accuracies. The method is described in the manual as the Quick Drift method. We also have a handy polar scope with right angle eyepiece, which is even quicker for rapid setup.��As for a permanent setup, you have lots of time to get the polar alignment for best compromise between pointing and tracking in both axes. You can also add modeling software which can remove��the remaining��pointing/tracking errors. For polar alignment I have used PEMPro to remove drift. You can do the classic drift method, or you zero Dec drift with the azimuth axis and remove RA drift with the altitude axis to get the best overall pointing/tracking performance. That is my normal method for aligning a permanent mount.��Rolando����-----Original Message-----

From: gc.iaffaldano@... [ap-gto] ap-gto@yahoogroups.com>

To: ap-gto ap-gto@yahoogroups.com>

Sent: Thu, Oct 30, 2014 3:25 pm

Subject: Re: [ap-gto] Re: a continue Resync, why?





This is more reasonable because the ascom tells ��me that the mount is in sideral tracking and i believe to the mount like i believe that my accessories have no flexure of this type; but if PolarAlignMax does a not perfect alignment because it uses only DEC moves what software i have to use to do a good alignment? Has the AP software a routine to do a more precise alignment? in the past i have used for my previuos mount a proprietary software of alignment to 3 stars or more ( alignment to model stars) that can avoid any errors and conic error too; but for AP that has a better mechanical funcionality what i have to do?







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#45687 Oct 30, 2014

thanks. I have the mount in a remote observatory; if i have more details ��to ask i ��would ��re-contact ��you.



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#45715 Nov 3, 2014

Thinking about this more lets take it to extreme. ��He is imaging vega for 3 hours. ��When it starts the yellow and red circle are match. ��At the end they are off 15 degrees. ��But he is still imaging Vega. ��The only thing I can see if that sky X is not getting the right position from the mount.

So I will have him enable the Maxim DL observatory control and see if it does the same thing, it should right if software is not the issue. ��



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#45728 Nov 4, 2014

I guess a extreme example was not a good idea. But Carmine tells me that it is only 15 arc min or so it could be flexure, �� I don't use Sky X or anything else, have no need for it with AP ascom controlling scope��



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#45731 Nov 4, 2014

I guess I need to call support tomorrow and see why this is happening. ��Flexure does not make sense too much. ��I mean if the telescope fell off the mount, it is tracking ok still and the sky X should have the yellow icon in the same spot. I am not sure to look for in software settings really

Howard, I will be on site after 5pm MST if you have any ideas I can try



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#45732 Nov 4, 2014

I guess I need to call support tomorrow and see why this is happening. Flexure does not make sense too much. I

> mean if the telescope fell off the mount, it is tracking ok still and the sky X should have the yellow icon in the same

> spot. I am not sure to look for in software settings really



I haven't been following this thread very carefully but are you sure that the setting you are looking isn't in SkyX? I believe there is an option for telescope modeling which you will probably want to turn off.



-Ray Gralak

Author of Astro-Physics Command Center (APCC)

Author of PEMPro: www.ccdware.com

Author of Astro-Physics V2 ASCOM Driver: www.gralak.com/apdriver

Author of PulseGuide: www.pulseguide.com

Author of Sigma: www.gralak.com/sigma



> -----Original Message-----

> From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com]

> Sent: Tuesday, November 04, 2014 2:09 PM

> To: ap-gto@yahoogroups.com

> Subject: Re: [ap-gto] Re: a continue Resync, why?

>

>

>

> I guess I need to call support tomorrow and see why this is happening. Flexure does not make sense too much. I

> mean if the telescope fell off the mount, it is tracking ok still and the sky X should have the yellow icon in the same

> spot. I am not sure to look for in software settings really

>

> Howard, I will be on site after 5pm MST if you have any ideas I can try

>

>



----------------------------

#45738 Nov 4, 2014

��I thank all those who have tried to give us a hand here and at the factory, as always the great friend Howard, but then it occurred to me that having disassembled the A.R. motor for the reason that Howard knows, the old PEM left on could interfere with the sidereal tracking; so the issue is solved. There is no sky error, no software error, no flexure error, only a human error of management of the mount.Bye.

Carmine



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#45740 Nov 4, 2014

Carmine,



15 arc-minutes of periodic error? That doesn't sound correct. Sorry, but it can't just be because of PEM unless the curve was bad.



-Ray Gralak

Author of Astro-Physics Command Center (APCC)

Author of PEMPro: www.ccdware.com

Author of Astro-Physics V2 ASCOM Driver: www.gralak.com/apdriver

Author of PulseGuide: www.pulseguide.com

Author of Sigma: www.gralak.com/sigma



> -----Original Message-----

> From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com]

> Sent: Tuesday, November 04, 2014 10:11 PM

> To: ap-gto@yahoogroups.com

> Subject: RE: [ap-gto] Re: a continue Resync, why?

>

>

>

> I thank all those who have tried to give us a hand here and at the factory, as always the great friend Howard, but

> then it occurred to me that having disassembled the A.R. motor for the reason that Howard knows, the old PEM left

> on could interfere with the sidereal tracking; so the issue is solved. There is no sky error, no software error, no

> flexure error, only a human error of management of the mount.

> Bye.

>

> Carmine

>

>

>

>

>



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#45742 Nov 4, 2014

I'm sorry but you have to talk with Howard to better understand, I can not make myself understood.Thanks.



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#45744 Nov 5, 2014

If the worm gear is rotated other than under control by the GTOCP3, the

> stored curve will likely be out of sync with the worm. In fact the

> resulting corrections could even amplify the apparent worm error

> considerably.



Assuming there was just a phase shift the periodic error would appear to be at most doubled. That should still be a long

way off from 15 arc-minutes of tracking error. Besides periodic error alone shouldn't cause long-term RA drift unless

the stored curve was bad.



-Ray Gralak

Author of Astro-Physics Command Center (APCC)

Author of PEMPro: www.ccdware.com

Author of Astro-Physics V2 ASCOM Driver: www.gralak.com/apdriver

Author of PulseGuide: www.pulseguide.com

Author of Sigma: www.gralak.com/sigma

> -----Original Message-----

> From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com]

> Sent: Wednesday, November 05, 2014 1:27 AM

> To: ap-gto@yahoogroups.com

> Subject: RE: [ap-gto] Re: a continue Resync, why?

>

>

>

> If the worm gear is rotated other than under control by the GTOCP3, the

> stored curve will likely be out of sync with the worm. In fact the

> resulting corrections could even amplify the apparent worm error

> considerably.

>

> Christopher Erickson

> Consulting Engineer

> Summit Kinetics

> Waikoloa, HI 96738

> www.summitkinetics.com

>

> -----Original Message-----

> From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com]

> Sent: Wednesday, November 05, 2014 12:06 AM

> To: ap-gto@yahoogroups.com

> Subject: RE: [ap-gto] Re: a continue Resync, why?

>

> Carmine,

>

> 15 arc-minutes of periodic error? That doesn't sound correct. Sorry, but it

> can't just be because of PEM unless the curve was bad.

>

> -Ray Gralak

> Author of Astro-Physics Command Center (APCC)

> Author of PEMPro: www.ccdware.com

> Author of Astro-Physics V2 ASCOM Driver: www.gralak.com/apdriver

> Author of PulseGuide: www.pulseguide.com

> Author of Sigma: www.gralak.com/sigma

>

> > -----Original Message-----

> > From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com]

> > Sent: Tuesday, November 04, 2014 10:11 PM

> > To: ap-gto@yahoogroups.com

> > Subject: RE: [ap-gto] Re: a continue Resync, why?

> >

> >

> >

> > I thank all those who have tried to give us a hand here and at the

> factory, as always the great friend Howard, but

> > then it occurred to me that having disassembled the A.R. motor for the

> reason that Howard knows, the old PEM left

> > on could interfere with the sidereal tracking; so the issue is solved.

> There is no sky error, no software error, no

> > flexure error, only a human error of management of the mount.

> > Bye.

> >

> > Carmine

> >

> >

> >

> >

> >

>

---------------

> Posted by: "Ray Gralak \(Groups\)" groups2@...>

---------------

>

> To UNSUBSCRIBE, or for general information on the ap-gto list

> see groups.yahoo.com/group/ap-gto

---------------

>

> Yahoo Groups Links

>

>

>

>







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#45746 Nov 5, 2014

Yes the curve is bad ...... and it affected the mount decelerating the sidereal tracking.



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#45749 Nov 5, 2014

We found the problem with this issue. ��The AP 1100 control box was replaced for another issue. ��He had a PEC enabled from the old control box. ��When we switched it was using the same PEC, which I suspect was not programmed in the mount. ��Not sure why the PEC setting on would do it it did not exist in the mount.

Anway, we disabled it and from what I heard last from Carmine it is working now. ��I either forgot or was not aware this was from the old box we switched out.



----------------------------

#45751 Nov 5, 2014

yes... we have a PEM (or PEC) that don't match with the motor and worm reinstalled again with a new gear mesh; so we have to remake the PEM like the instructions of AP well reported.



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