appm trailing stars at specific DEC


 

Hi everyone

(logs/images at the end of post)

Has anyone else seen this? ideas or suggestions appreciated

Building a model in APPM 1.9.0.1, stars in images are trailing at specific sky areas specifically at DEC 50 and parts of DEC 70

I have a long (to me) 30 second settle time for the mount, and enabled "required high accuracy slews" - still end up with long streaking stars of a consistent distance. 

this example crop is @ 100%
image.png

 
during the settling time, APPM will display "Slew warning". the log shows coordinates oscillating in RA  - example log excerpt at the end of this post

Outside of DEC 50 and 70, model images look fine, round stars, etc.

I even bumped up settle time to 120 seconds, which lessened the number of these, but still see them

Important detail: We switched from CDK17 to CDK20, and went through balancing and polar alignment, etc. It's been suggested that some of our mount parameters may need to be tweaked by AP experts. 


example "Slew Warning" 
0000262 2021-09-01 19:05:06.330:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 38.63s /  -70° 00' 00.2")
0000263 2021-09-01 19:05:08.130:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 37.49s /  -69° 59' 59.6")
0000264 2021-09-01 19:05:09.725:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 38.06s /  -70° 00' 00.3")
0000265 2021-09-01 19:05:11.331:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 41.59s /  -70° 00' 00.4")
0000266 2021-09-01 19:05:13.174:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 37.37s /  -69° 59' 59.3")
0000267 2021-09-01 19:05:14.794:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 38.44s /  -69° 59' 59.7")
0000268 2021-09-01 19:05:16.386:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 37.31s /  -69° 59' 59.9")
0000269 2021-09-01 19:05:18.202:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 39.33s /  -70° 00' 00.1")
0000270 2021-09-01 19:05:19.804:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 38.41s /  -70° 00' 00.1")
0000271 2021-09-01 19:05:21.372:     Severe,    SLEW WARNING, Slew did not reach destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 38.41s /  -70° 00' 00.1")

Image files of entire run (including good and failed fits) and log:

--
Brian 



Brian Valente


Roland Christen
 

By anyone, you probably mean me. If you have a lot of moment arm on the mount (lots of heavy counterweights far down on the cwt shaft), then you might have a situation where the scope is doing a bit of pendulum motion. Can't tell which axis by your image, but probably RA. You say Dec 50 and 70, but it's probably when the counterweight shaft is near horizontal and the scope is pointing near the meridian. That's the place where all the moments add to give you the least stability and the most moment reaction on the RA axis.

We can tame that, so i can provide you with some specific instructions that you can enter via APCC.

Roland



-----Original Message-----
From: Brian Valente <bvalente@...>
To: main@ap-gto.groups.io
Sent: Thu, Sep 9, 2021 3:25 pm
Subject: [ap-gto] appm trailing stars at specific DEC

Hi everyone

(logs/images at the end of post)

Has anyone else seen this? ideas or suggestions appreciated

Building a model in APPM 1.9.0.1, stars in images are trailing at specific sky areas specifically at DEC 50 and parts of DEC 70

I have a long (to me) 30 second settle time for the mount, and enabled "required high accuracy slews" - still end up with long streaking stars of a consistent distance. 

this example crop is @ 100%
image.png

 
during the settling time, APPM will display "Slew warning". the log shows coordinates oscillating in RA  - example log excerpt at the end of this post

Outside of DEC 50 and 70, model images look fine, round stars, etc.

I even bumped up settle time to 120 seconds, which lessened the number of these, but still see them

Important detail: We switched from CDK17 to CDK20, and went through balancing and polar alignment, etc. It's been suggested that some of our mount parameters may need to be tweaked by AP experts. 


example "Slew Warning" 
0000262 2021-09-01 19:05:06.330:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 38.63s /  -70° 00' 00.2")
0000263 2021-09-01 19:05:08.130:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 37.49s /  -69° 59' 59.6")
0000264 2021-09-01 19:05:09.725:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 38.06s /  -70° 00' 00.3")
0000265 2021-09-01 19:05:11.331:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 41.59s /  -70° 00' 00.4")
0000266 2021-09-01 19:05:13.174:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 37.37s /  -69° 59' 59.3")
0000267 2021-09-01 19:05:14.794:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 38.44s /  -69° 59' 59.7")
0000268 2021-09-01 19:05:16.386:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 37.31s /  -69° 59' 59.9")
0000269 2021-09-01 19:05:18.202:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 39.33s /  -70° 00' 00.1")
0000270 2021-09-01 19:05:19.804:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 38.41s /  -70° 00' 00.1")
0000271 2021-09-01 19:05:21.372:     Severe,    SLEW WARNING, Slew did not reach destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 38.41s /  -70° 00' 00.1")

Image files of entire run (including good and failed fits) and log:

--
Brian 



Brian Valente

--
Roland Christen
Astro-Physics


 

Thanks Roland

Howard and others helped us previously to tune 17", so I wasn't thinking of you specifically ;)



On Thu, Sep 9, 2021 at 1:53 PM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
By anyone, you probably mean me. If you have a lot of moment arm on the mount (lots of heavy counterweights far down on the cwt shaft), then you might have a situation where the scope is doing a bit of pendulum motion. Can't tell which axis by your image, but probably RA. You say Dec 50 and 70, but it's probably when the counterweight shaft is near horizontal and the scope is pointing near the meridian. That's the place where all the moments add to give you the least stability and the most moment reaction on the RA axis.

We can tame that, so i can provide you with some specific instructions that you can enter via APCC.

Roland



-----Original Message-----
From: Brian Valente <bvalente@...>
To: main@ap-gto.groups.io
Sent: Thu, Sep 9, 2021 3:25 pm
Subject: [ap-gto] appm trailing stars at specific DEC

Hi everyone

(logs/images at the end of post)

Has anyone else seen this? ideas or suggestions appreciated

Building a model in APPM 1.9.0.1, stars in images are trailing at specific sky areas specifically at DEC 50 and parts of DEC 70

I have a long (to me) 30 second settle time for the mount, and enabled "required high accuracy slews" - still end up with long streaking stars of a consistent distance. 

this example crop is @ 100%
image.png

 
during the settling time, APPM will display "Slew warning". the log shows coordinates oscillating in RA  - example log excerpt at the end of this post

Outside of DEC 50 and 70, model images look fine, round stars, etc.

I even bumped up settle time to 120 seconds, which lessened the number of these, but still see them

Important detail: We switched from CDK17 to CDK20, and went through balancing and polar alignment, etc. It's been suggested that some of our mount parameters may need to be tweaked by AP experts. 


example "Slew Warning" 
0000262 2021-09-01 19:05:06.330:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 38.63s /  -70° 00' 00.2")
0000263 2021-09-01 19:05:08.130:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 37.49s /  -69° 59' 59.6")
0000264 2021-09-01 19:05:09.725:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 38.06s /  -70° 00' 00.3")
0000265 2021-09-01 19:05:11.331:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 41.59s /  -70° 00' 00.4")
0000266 2021-09-01 19:05:13.174:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 37.37s /  -69° 59' 59.3")
0000267 2021-09-01 19:05:14.794:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 38.44s /  -69° 59' 59.7")
0000268 2021-09-01 19:05:16.386:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 37.31s /  -69° 59' 59.9")
0000269 2021-09-01 19:05:18.202:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 39.33s /  -70° 00' 00.1")
0000270 2021-09-01 19:05:19.804:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 38.41s /  -70° 00' 00.1")
0000271 2021-09-01 19:05:21.372:     Severe,    SLEW WARNING, Slew did not reach destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 38.41s /  -70° 00' 00.1")

Image files of entire run (including good and failed fits) and log:

--
Brian 



Brian Valente

--
Roland Christen
Astro-Physics



--
Brian 



Brian Valente


Roland Christen
 

I don't suppose you are there by the scope when it does this, so you can't really tell me what is happening at the motor level in each axis?

Roland


-----Original Message-----
From: Brian Valente <bvalente@...>
To: main@ap-gto.groups.io
Sent: Thu, Sep 9, 2021 5:42 pm
Subject: Re: [ap-gto] appm trailing stars at specific DEC

Thanks Roland

Howard and others helped us previously to tune 17", so I wasn't thinking of you specifically ;)



On Thu, Sep 9, 2021 at 1:53 PM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
By anyone, you probably mean me. If you have a lot of moment arm on the mount (lots of heavy counterweights far down on the cwt shaft), then you might have a situation where the scope is doing a bit of pendulum motion. Can't tell which axis by your image, but probably RA. You say Dec 50 and 70, but it's probably when the counterweight shaft is near horizontal and the scope is pointing near the meridian. That's the place where all the moments add to give you the least stability and the most moment reaction on the RA axis.

We can tame that, so i can provide you with some specific instructions that you can enter via APCC.

Roland



-----Original Message-----
From: Brian Valente <bvalente@...>
To: main@ap-gto.groups.io
Sent: Thu, Sep 9, 2021 3:25 pm
Subject: [ap-gto] appm trailing stars at specific DEC

Hi everyone

(logs/images at the end of post)

Has anyone else seen this? ideas or suggestions appreciated

Building a model in APPM 1.9.0.1, stars in images are trailing at specific sky areas specifically at DEC 50 and parts of DEC 70

I have a long (to me) 30 second settle time for the mount, and enabled "required high accuracy slews" - still end up with long streaking stars of a consistent distance. 

this example crop is @ 100%
image.png

 
during the settling time, APPM will display "Slew warning". the log shows coordinates oscillating in RA  - example log excerpt at the end of this post

Outside of DEC 50 and 70, model images look fine, round stars, etc.

I even bumped up settle time to 120 seconds, which lessened the number of these, but still see them

Important detail: We switched from CDK17 to CDK20, and went through balancing and polar alignment, etc. It's been suggested that some of our mount parameters may need to be tweaked by AP experts. 


example "Slew Warning" 
0000262 2021-09-01 19:05:06.330:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 38.63s /  -70° 00' 00.2")
0000263 2021-09-01 19:05:08.130:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 37.49s /  -69° 59' 59.6")
0000264 2021-09-01 19:05:09.725:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 38.06s /  -70° 00' 00.3")
0000265 2021-09-01 19:05:11.331:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 41.59s /  -70° 00' 00.4")
0000266 2021-09-01 19:05:13.174:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 37.37s /  -69° 59' 59.3")
0000267 2021-09-01 19:05:14.794:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 38.44s /  -69° 59' 59.7")
0000268 2021-09-01 19:05:16.386:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 37.31s /  -69° 59' 59.9")
0000269 2021-09-01 19:05:18.202:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 39.33s /  -70° 00' 00.1")
0000270 2021-09-01 19:05:19.804:    Warning,    SLEW WARNING, Slew has not reached destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 38.41s /  -70° 00' 00.1")
0000271 2021-09-01 19:05:21.372:     Severe,    SLEW WARNING, Slew did not reach destination: Target=( 18h 58m 39.41s /  -70° 00' 00.0") -- Mount=( 18h 58m 38.41s /  -70° 00' 00.1")

Image files of entire run (including good and failed fits) and log:

--
Brian 



Brian Valente

--
Roland Christen
Astro-Physics


--
Brian 



Brian Valente

--
Roland Christen
Astro-Physics