Mach2 - Elongated stars


yanzhe liu
 

Testing new mach2 for a couple of nights. It works great out of the box and I am very pleased.

One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
The exact same telescope/CCD were used with another mount and stars were round, I am wondering what I should check (I think there was due to some setup issue, but I could not figure it out).
- Used OAG for guiding, so there should not be any flexure.
- CCD orientation was 0/180 degree. The stars were elongated top to bottom.
-  I did polar alignment with PHD2 drift align. PA error should be < 5'. The field rotation of each sub is ~0.01 degree, much larger than the other system (but elongated stars do not look like field rotation, they were same across the image)
- Both RA and DEC guiding curves looked smooth, had similar RMS. DEC correction was mainly to one direction.
- DEC balance was slightly off, camera heavy. Is Mach2 DEC sensitive to this? Will the guiding/image be affected?

I dont think any of the above is of particular concern, except DEC balance. Any comment/help is appreciated.


Ray Gralak
 

One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
Can you describe your imaging setup? (Telescope, camera, image scale, etc.)

Is it possible the issue is optical (collimation) or caused by vibrations from the camera's fan?

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
Sent: Saturday, March 6, 2021 10:44 PM
To: main@ap-gto.groups.io
Subject: [ap-gto] Mach2 - Elongated stars

Testing new mach2 for a couple of nights. It works great out of the box and I am very pleased.

One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
The exact same telescope/CCD were used with another mount and stars were round, I am wondering what I should
check (I think there was due to some setup issue, but I could not figure it out).
- Used OAG for guiding, so there should not be any flexure.
- CCD orientation was 0/180 degree. The stars were elongated top to bottom.
- I did polar alignment with PHD2 drift align. PA error should be < 5'. The field rotation of each sub is ~0.01 degree,
much larger than the other system (but elongated stars do not look like field rotation, they were same across the
image)
- Both RA and DEC guiding curves looked smooth, had similar RMS. DEC correction was mainly to one direction.
- DEC balance was slightly off, camera heavy. Is Mach2 DEC sensitive to this? Will the guiding/image be affected?

I dont think any of the above is of particular concern, except DEC balance. Any comment/help is appreciated.


Roland Christen
 

If your guiding was spot on, then the mount is working correctly. It is not a balance or setup issue. Balance would not cause oval stars. The mount would be suspect if one axis had rms guide values that were twice as high as the other axis.
Dec correction mainly in one direction means your polar alignment in azimuth was off. You can see that if you turn correction off and let the mount drift in Dec.
Elongated stars top to bottom ? you did not specify if that was RA or Dec.

Rolando

-----Original Message-----
From: yanzhe liu <liuyanzhe@...>
To: main@ap-gto.groups.io
Sent: Sun, Mar 7, 2021 12:44 am
Subject: [ap-gto] Mach2 - Elongated stars

Testing new mach2 for a couple of nights. It works great out of the box and I am very pleased.

One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
The exact same telescope/CCD were used with another mount and stars were round, I am wondering what I should check (I think there was due to some setup issue, but I could not figure it out).
- Used OAG for guiding, so there should not be any flexure.
- CCD orientation was 0/180 degree. The stars were elongated top to bottom.
-  I did polar alignment with PHD2 drift align. PA error should be < 5'. The field rotation of each sub is ~0.01 degree, much larger than the other system (but elongated stars do not look like field rotation, they were same across the image)
- Both RA and DEC guiding curves looked smooth, had similar RMS. DEC correction was mainly to one direction.
- DEC balance was slightly off, camera heavy. Is Mach2 DEC sensitive to this? Will the guiding/image be affected?

I dont think any of the above is of particular concern, except DEC balance. Any comment/help is appreciated.

--
Roland Christen
Astro-Physics


Roland Christen
 

Take a short exposure (1 sec or less) of a bright star inside, outside and at focus. I was shooting the other day when the temperature was dropping rapidly after sunset and got heat plumes for about 1 hour in my 160 refractor. Made the stars look oval during that time. I could easily see the heat plumes when the star was defocused. Things like this should be checked when you start off in your imaging run. After about 2 hours the stars were perfectly round during my focus runs.

Rolando

-----Original Message-----
From: Ray Gralak <iogroups@...>
To: main@ap-gto.groups.io
Sent: Sun, Mar 7, 2021 10:24 am
Subject: Re: [ap-gto] Mach2 - Elongated stars

> One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).

Can you describe your imaging setup? (Telescope, camera, image scale, etc.)

Is it possible the issue is optical (collimation) or caused by vibrations from the camera's fan?

-Ray

> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
> Sent: Saturday, March 6, 2021 10:44 PM
> To: main@ap-gto.groups.io
> Subject: [ap-gto] Mach2 - Elongated stars
>
> Testing new mach2 for a couple of nights. It works great out of the box and I am very pleased.
>
> One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
> The exact same telescope/CCD were used with another mount and stars were round, I am wondering what I should
> check (I think there was due to some setup issue, but I could not figure it out).
> - Used OAG for guiding, so there should not be any flexure.
> - CCD orientation was 0/180 degree. The stars were elongated top to bottom.
> -  I did polar alignment with PHD2 drift align. PA error should be < 5'. The field rotation of each sub is ~0.01 degree,
> much larger than the other system (but elongated stars do not look like field rotation, they were same across the
> image)
> - Both RA and DEC guiding curves looked smooth, had similar RMS. DEC correction was mainly to one direction.
> - DEC balance was slightly off, camera heavy. Is Mach2 DEC sensitive to this? Will the guiding/image be affected?
>
> I dont think any of the above is of particular concern, except DEC balance. Any comment/help is appreciated.
>







--
Roland Christen
Astro-Physics


Roland Christen
 

Couple of questions:

1 - what's the mount's serial number
2 - which axis is the elongation
3 - which direction was the scope pointing (RA-Dec)
4 - what scope and focal length or what is the arc sec per pixel.
5 - do you have a picture of your setup?

One comment about balance - it should be easy for you to completely balance the scope with the clutches loose. Can you estimate how many lb out of balance your scope is in Dec? Normally i would not think this would have any effect, but doesn't hurt to check this.

Roland Christen
Astro-Physics Inc.



-----Original Message-----
From: yanzhe liu <liuyanzhe@...>
To: main@ap-gto.groups.io
Sent: Sun, Mar 7, 2021 12:44 am
Subject: [ap-gto] Mach2 - Elongated stars

Testing new mach2 for a couple of nights. It works great out of the box and I am very pleased.

One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
The exact same telescope/CCD were used with another mount and stars were round, I am wondering what I should check (I think there was due to some setup issue, but I could not figure it out).
- Used OAG for guiding, so there should not be any flexure.
- CCD orientation was 0/180 degree. The stars were elongated top to bottom.
-  I did polar alignment with PHD2 drift align. PA error should be < 5'. The field rotation of each sub is ~0.01 degree, much larger than the other system (but elongated stars do not look like field rotation, they were same across the image)
- Both RA and DEC guiding curves looked smooth, had similar RMS. DEC correction was mainly to one direction.
- DEC balance was slightly off, camera heavy. Is Mach2 DEC sensitive to this? Will the guiding/image be affected?

I dont think any of the above is of particular concern, except DEC balance. Any comment/help is appreciated.

--
Roland Christen
Astro-Physics


yanzhe liu
 

My setup is FSQ106+OAG+16803. The same setup has been used for a while with a different mount, so it is unlikely the collimation or fan issue.

Yanzhe

On Sun, Mar 7, 2021 at 8:25 AM Ray Gralak <iogroups@...> wrote:
> One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).

Can you describe your imaging setup? (Telescope, camera, image scale, etc.)

Is it possible the issue is optical (collimation) or caused by vibrations from the camera's fan?

-Ray

> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
> Sent: Saturday, March 6, 2021 10:44 PM
> To: main@ap-gto.groups.io
> Subject: [ap-gto] Mach2 - Elongated stars
>
> Testing new mach2 for a couple of nights. It works great out of the box and I am very pleased.
>
> One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
> The exact same telescope/CCD were used with another mount and stars were round, I am wondering what I should
> check (I think there was due to some setup issue, but I could not figure it out).
> - Used OAG for guiding, so there should not be any flexure.
> - CCD orientation was 0/180 degree. The stars were elongated top to bottom.
> -  I did polar alignment with PHD2 drift align. PA error should be < 5'. The field rotation of each sub is ~0.01 degree,
> much larger than the other system (but elongated stars do not look like field rotation, they were same across the
> image)
> - Both RA and DEC guiding curves looked smooth, had similar RMS. DEC correction was mainly to one direction.
> - DEC balance was slightly off, camera heavy. Is Mach2 DEC sensitive to this? Will the guiding/image be affected?
>
> I dont think any of the above is of particular concern, except DEC balance. Any comment/help is appreciated.
>







yanzhe liu
 

Roland,

I will check my mount serial number later as I just packed everything due to rain forecast.

My camera's orientation was 0/180 degree, so I assume top to bottom elongation would be DEC.

I dont have any picture of my setup, I just tore it down since it will be rainy this week. My setup is FSQ106+OAG+16803, image scale is 3.5".
I was imaging Rosetta Nebula, after it was just past meridian for 2-3 hours.

I used PHD2 drift for PA, it reported <5' PA error, I am waiting for polemaster adapter so I can confirm I get good PA next time. 

DEC was out of balance because my setup was rear end heavy, if it was in balance position then I could not rotate my CCD in all directions. My guess is that the DEC balance was off by less than 1lb. In the next test, I can balance DEC to see if the issue still exists.

My suspicion is that if DEC balance is off, then DEC might creep under gravity, even PA is perfect. So you might see DEC continually drift  then gets corrected by PHD2 periodically.

Yanzhe

On Sun, Mar 7, 2021 at 9:35 AM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
Couple of questions:

1 - what's the mount's serial number
2 - which axis is the elongation
3 - which direction was the scope pointing (RA-Dec)
4 - what scope and focal length or what is the arc sec per pixel.
5 - do you have a picture of your setup?

One comment about balance - it should be easy for you to completely balance the scope with the clutches loose. Can you estimate how many lb out of balance your scope is in Dec? Normally i would not think this would have any effect, but doesn't hurt to check this.

Roland Christen
Astro-Physics Inc.



-----Original Message-----
From: yanzhe liu <liuyanzhe@...>
To: main@ap-gto.groups.io
Sent: Sun, Mar 7, 2021 12:44 am
Subject: [ap-gto] Mach2 - Elongated stars

Testing new mach2 for a couple of nights. It works great out of the box and I am very pleased.

One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
The exact same telescope/CCD were used with another mount and stars were round, I am wondering what I should check (I think there was due to some setup issue, but I could not figure it out).
- Used OAG for guiding, so there should not be any flexure.
- CCD orientation was 0/180 degree. The stars were elongated top to bottom.
-  I did polar alignment with PHD2 drift align. PA error should be < 5'. The field rotation of each sub is ~0.01 degree, much larger than the other system (but elongated stars do not look like field rotation, they were same across the image)
- Both RA and DEC guiding curves looked smooth, had similar RMS. DEC correction was mainly to one direction.
- DEC balance was slightly off, camera heavy. Is Mach2 DEC sensitive to this? Will the guiding/image be affected?

I dont think any of the above is of particular concern, except DEC balance. Any comment/help is appreciated.

--
Roland Christen
Astro-Physics


Roland Christen
 


My suspicion is that if DEC balance is off, then DEC might creep under gravity, even PA is perfect. So you might see DEC continually drift  then gets corrected by PHD2 periodically.
Do you have a picture of your guide chart? The Dec axis would not creep under gravity if the clutches are tight. I just checked a mount with 3 lb out of balance in Dec and see zero creep or any other guide issue. The main thing that happens when you have polar axis error in azimuth is that the guider will always be off in Dec. The guide star is constantly being pushed back towards zero when it reaches the Min Move setting, so it will always have a minimum elongation error of your Min Move setting. So, if the Min Move is set high in Dec, you will get a high error in Dec. Best practices is to zero out your Dec drift and use a low Min Move setting. In my normal settings, my Min Move is .02 seconds, which translates to 0.3 arc seconds at 1x guide rate (0.2sec x 15arc sec/sec = 0.3 arc sec).

I always check my Dec drift to make sure that it is reasonable. You can do this by turning off guide pulses to the mount while recording the drift in the two axes. I do this near the meridian with scope on the west side of the mount pointing within 1 hour of the meridian. In my camera I use MaximDL in focus mode with a crosshair and watch the slow drift of a guide star in Dec (Dec is Up-Down on my camera). If the star moves down, I turn the right hand azimuth knob which moves the star to the right on my camera image. You can also do it with PEMPro and with PHD2 by watching the graph for a few minutes. In my method, if the star moves 5 arc sec in 2 minutes the amount of adjustment in azimuth is approximately 1/2 turn of the Azimuth knob. I can usually get the drift down to less than 1 arc sec per 5 minutes. I can do this in the daytime on a star as faint as magnitude 5 using my H-a filter.

Rolando

-----Original Message-----
From: yanzhe liu <liuyanzhe@...>
To: main@ap-gto.groups.io
Sent: Sun, Mar 7, 2021 12:11 pm
Subject: Re: [ap-gto] Mach2 - Elongated stars

Roland,

I will check my mount serial number later as I just packed everything due to rain forecast.

My camera's orientation was 0/180 degree, so I assume top to bottom elongation would be DEC.

I dont have any picture of my setup, I just tore it down since it will be rainy this week. My setup is FSQ106+OAG+16803, image scale is 3.5".
I was imaging Rosetta Nebula, after it was just past meridian for 2-3 hours.

I used PHD2 drift for PA, it reported <5' PA error, I am waiting for polemaster adapter so I can confirm I get good PA next time. 

DEC was out of balance because my setup was rear end heavy, if it was in balance position then I could not rotate my CCD in all directions. My guess is that the DEC balance was off by less than 1lb. In the next test, I can balance DEC to see if the issue still exists.

My suspicion is that if DEC balance is off, then DEC might creep under gravity, even PA is perfect. So you might see DEC continually drift  then gets corrected by PHD2 periodically.

Yanzhe

On Sun, Mar 7, 2021 at 9:35 AM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
Couple of questions:

1 - what's the mount's serial number
2 - which axis is the elongation
3 - which direction was the scope pointing (RA-Dec)
4 - what scope and focal length or what is the arc sec per pixel.
5 - do you have a picture of your setup?

One comment about balance - it should be easy for you to completely balance the scope with the clutches loose. Can you estimate how many lb out of balance your scope is in Dec? Normally i would not think this would have any effect, but doesn't hurt to check this.

Roland Christen
Astro-Physics Inc.



-----Original Message-----
From: yanzhe liu <liuyanzhe@...>
To: main@ap-gto.groups.io
Sent: Sun, Mar 7, 2021 12:44 am
Subject: [ap-gto] Mach2 - Elongated stars

Testing new mach2 for a couple of nights. It works great out of the box and I am very pleased.

One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
The exact same telescope/CCD were used with another mount and stars were round, I am wondering what I should check (I think there was due to some setup issue, but I could not figure it out).
- Used OAG for guiding, so there should not be any flexure.
- CCD orientation was 0/180 degree. The stars were elongated top to bottom.
-  I did polar alignment with PHD2 drift align. PA error should be < 5'. The field rotation of each sub is ~0.01 degree, much larger than the other system (but elongated stars do not look like field rotation, they were same across the image)
- Both RA and DEC guiding curves looked smooth, had similar RMS. DEC correction was mainly to one direction.
- DEC balance was slightly off, camera heavy. Is Mach2 DEC sensitive to this? Will the guiding/image be affected?

I dont think any of the above is of particular concern, except DEC balance. Any comment/help is appreciated.

--
Roland Christen
Astro-Physics

--
Roland Christen
Astro-Physics


Ray Gralak
 

Hi Yanzhe,

Can you zip and post your PHD2 logs, as well as APCC/AP V2 ASCOM driver logs?

There might be something useful there.

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
Sent: Sunday, March 7, 2021 10:12 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Mach2 - Elongated stars

Roland,

I will check my mount serial number later as I just packed everything due to rain forecast.

My camera's orientation was 0/180 degree, so I assume top to bottom elongation would be DEC.

I dont have any picture of my setup, I just tore it down since it will be rainy this week. My setup is
FSQ106+OAG+16803, image scale is 3.5".
I was imaging Rosetta Nebula, after it was just past meridian for 2-3 hours.

I used PHD2 drift for PA, it reported <5' PA error, I am waiting for polemaster adapter so I can confirm I get good PA
next time.

DEC was out of balance because my setup was rear end heavy, if it was in balance position then I could not rotate
my CCD in all directions. My guess is that the DEC balance was off by less than 1lb. In the next test, I can balance
DEC to see if the issue still exists.

My suspicion is that if DEC balance is off, then DEC might creep under gravity, even PA is perfect. So you might
see DEC continually drift then gets corrected by PHD2 periodically.

Yanzhe

On Sun, Mar 7, 2021 at 9:35 AM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:


Couple of questions:


1 - what's the mount's serial number
2 - which axis is the elongation
3 - which direction was the scope pointing (RA-Dec)
4 - what scope and focal length or what is the arc sec per pixel.
5 - do you have a picture of your setup?



One comment about balance - it should be easy for you to completely balance the scope with the clutches
loose. Can you estimate how many lb out of balance your scope is in Dec? Normally i would not think this would
have any effect, but doesn't hurt to check this.



Roland Christen
Astro-Physics Inc.




-----Original Message-----
From: yanzhe liu <liuyanzhe@gmail.com>
To: main@ap-gto.groups.io
Sent: Sun, Mar 7, 2021 12:44 am
Subject: [ap-gto] Mach2 - Elongated stars


Testing new mach2 for a couple of nights. It works great out of the box and I am very pleased.

One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
The exact same telescope/CCD were used with another mount and stars were round, I am wondering what I
should check (I think there was due to some setup issue, but I could not figure it out).
- Used OAG for guiding, so there should not be any flexure.
- CCD orientation was 0/180 degree. The stars were elongated top to bottom.
- I did polar alignment with PHD2 drift align. PA error should be < 5'. The field rotation of each sub is ~0.01
degree, much larger than the other system (but elongated stars do not look like field rotation, they were same
across the image)
- Both RA and DEC guiding curves looked smooth, had similar RMS. DEC correction was mainly to one
direction.
- DEC balance was slightly off, camera heavy. Is Mach2 DEC sensitive to this? Will the guiding/image be
affected?

I dont think any of the above is of particular concern, except DEC balance. Any comment/help is appreciated.

--
Roland Christen
Astro-Physics






yanzhe liu
 

I used PHD2 drift align, it looked good. But I am not sure because each sub had ~0.01-0.02 degree field rotation, which I did not expect with good PA.
I usually see big field rotation if PA is bad, but it appeared not field rotation this time.

Let me dig if I can find PHD2 log.



On Sun, Mar 7, 2021 at 10:36 AM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:

My suspicion is that if DEC balance is off, then DEC might creep under gravity, even PA is perfect. So you might see DEC continually drift  then gets corrected by PHD2 periodically.
Do you have a picture of your guide chart? The Dec axis would not creep under gravity if the clutches are tight. I just checked a mount with 3 lb out of balance in Dec and see zero creep or any other guide issue. The main thing that happens when you have polar axis error in azimuth is that the guider will always be off in Dec. The guide star is constantly being pushed back towards zero when it reaches the Min Move setting, so it will always have a minimum elongation error of your Min Move setting. So, if the Min Move is set high in Dec, you will get a high error in Dec. Best practices is to zero out your Dec drift and use a low Min Move setting. In my normal settings, my Min Move is .02 seconds, which translates to 0.3 arc seconds at 1x guide rate (0.2sec x 15arc sec/sec = 0.3 arc sec).

I always check my Dec drift to make sure that it is reasonable. You can do this by turning off guide pulses to the mount while recording the drift in the two axes. I do this near the meridian with scope on the west side of the mount pointing within 1 hour of the meridian. In my camera I use MaximDL in focus mode with a crosshair and watch the slow drift of a guide star in Dec (Dec is Up-Down on my camera). If the star moves down, I turn the right hand azimuth knob which moves the star to the right on my camera image. You can also do it with PEMPro and with PHD2 by watching the graph for a few minutes. In my method, if the star moves 5 arc sec in 2 minutes the amount of adjustment in azimuth is approximately 1/2 turn of the Azimuth knob. I can usually get the drift down to less than 1 arc sec per 5 minutes. I can do this in the daytime on a star as faint as magnitude 5 using my H-a filter.

Rolando

-----Original Message-----
From: yanzhe liu <liuyanzhe@...>
To: main@ap-gto.groups.io
Sent: Sun, Mar 7, 2021 12:11 pm
Subject: Re: [ap-gto] Mach2 - Elongated stars

Roland,

I will check my mount serial number later as I just packed everything due to rain forecast.

My camera's orientation was 0/180 degree, so I assume top to bottom elongation would be DEC.

I dont have any picture of my setup, I just tore it down since it will be rainy this week. My setup is FSQ106+OAG+16803, image scale is 3.5".
I was imaging Rosetta Nebula, after it was just past meridian for 2-3 hours.

I used PHD2 drift for PA, it reported <5' PA error, I am waiting for polemaster adapter so I can confirm I get good PA next time. 

DEC was out of balance because my setup was rear end heavy, if it was in balance position then I could not rotate my CCD in all directions. My guess is that the DEC balance was off by less than 1lb. In the next test, I can balance DEC to see if the issue still exists.

My suspicion is that if DEC balance is off, then DEC might creep under gravity, even PA is perfect. So you might see DEC continually drift  then gets corrected by PHD2 periodically.

Yanzhe

On Sun, Mar 7, 2021 at 9:35 AM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
Couple of questions:

1 - what's the mount's serial number
2 - which axis is the elongation
3 - which direction was the scope pointing (RA-Dec)
4 - what scope and focal length or what is the arc sec per pixel.
5 - do you have a picture of your setup?

One comment about balance - it should be easy for you to completely balance the scope with the clutches loose. Can you estimate how many lb out of balance your scope is in Dec? Normally i would not think this would have any effect, but doesn't hurt to check this.

Roland Christen
Astro-Physics Inc.



-----Original Message-----
From: yanzhe liu <liuyanzhe@...>
To: main@ap-gto.groups.io
Sent: Sun, Mar 7, 2021 12:44 am
Subject: [ap-gto] Mach2 - Elongated stars

Testing new mach2 for a couple of nights. It works great out of the box and I am very pleased.

One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
The exact same telescope/CCD were used with another mount and stars were round, I am wondering what I should check (I think there was due to some setup issue, but I could not figure it out).
- Used OAG for guiding, so there should not be any flexure.
- CCD orientation was 0/180 degree. The stars were elongated top to bottom.
-  I did polar alignment with PHD2 drift align. PA error should be < 5'. The field rotation of each sub is ~0.01 degree, much larger than the other system (but elongated stars do not look like field rotation, they were same across the image)
- Both RA and DEC guiding curves looked smooth, had similar RMS. DEC correction was mainly to one direction.
- DEC balance was slightly off, camera heavy. Is Mach2 DEC sensitive to this? Will the guiding/image be affected?

I dont think any of the above is of particular concern, except DEC balance. Any comment/help is appreciated.

--
Roland Christen
Astro-Physics

--
Roland Christen
Astro-Physics


yanzhe liu
 

Ray,

Where is ASCOM driver log? I dont use APCC, I use SGPro.

Yanzhe

On Sun, Mar 7, 2021 at 10:45 AM Ray Gralak <iogroups@...> wrote:
Hi Yanzhe,

Can you zip and post your PHD2 logs, as well as APCC/AP V2 ASCOM driver logs?

There might be something useful there.

-Ray

> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
> Sent: Sunday, March 7, 2021 10:12 AM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] Mach2 - Elongated stars
>
> Roland,
>
> I will check my mount serial number later as I just packed everything due to rain forecast.
>
> My camera's orientation was 0/180 degree, so I assume top to bottom elongation would be DEC.
>
> I dont have any picture of my setup, I just tore it down since it will be rainy this week. My setup is
> FSQ106+OAG+16803, image scale is 3.5".
> I was imaging Rosetta Nebula, after it was just past meridian for 2-3 hours.
>
> I used PHD2 drift for PA, it reported <5' PA error, I am waiting for polemaster adapter so I can confirm I get good PA
> next time.
>
> DEC was out of balance because my setup was rear end heavy, if it was in balance position then I could not rotate
> my CCD in all directions. My guess is that the DEC balance was off by less than 1lb. In the next test, I can balance
> DEC to see if the issue still exists.
>
> My suspicion is that if DEC balance is off, then DEC might creep under gravity, even PA is perfect. So you might
> see DEC continually drift  then gets corrected by PHD2 periodically.
>
> Yanzhe
>
> On Sun, Mar 7, 2021 at 9:35 AM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
>
>
>       Couple of questions:
>
>
>       1 - what's the mount's serial number
>       2 - which axis is the elongation
>       3 - which direction was the scope pointing (RA-Dec)
>       4 - what scope and focal length or what is the arc sec per pixel.
>       5 - do you have a picture of your setup?
>
>
>
>       One comment about balance - it should be easy for you to completely balance the scope with the clutches
> loose. Can you estimate how many lb out of balance your scope is in Dec? Normally i would not think this would
> have any effect, but doesn't hurt to check this.
>
>
>
>       Roland Christen
>       Astro-Physics Inc.
>
>
>
>
>       -----Original Message-----
>       From: yanzhe liu <liuyanzhe@...>
>       To: main@ap-gto.groups.io
>       Sent: Sun, Mar 7, 2021 12:44 am
>       Subject: [ap-gto] Mach2 - Elongated stars
>
>
>       Testing new mach2 for a couple of nights. It works great out of the box and I am very pleased.
>
>       One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
>       The exact same telescope/CCD were used with another mount and stars were round, I am wondering what I
> should check (I think there was due to some setup issue, but I could not figure it out).
>       - Used OAG for guiding, so there should not be any flexure.
>       - CCD orientation was 0/180 degree. The stars were elongated top to bottom.
>       -  I did polar alignment with PHD2 drift align. PA error should be < 5'. The field rotation of each sub is ~0.01
> degree, much larger than the other system (but elongated stars do not look like field rotation, they were same
> across the image)
>       - Both RA and DEC guiding curves looked smooth, had similar RMS. DEC correction was mainly to one
> direction.
>       - DEC balance was slightly off, camera heavy. Is Mach2 DEC sensitive to this? Will the guiding/image be
> affected?
>
>       I dont think any of the above is of particular concern, except DEC balance. Any comment/help is appreciated.
>
>       --
>       Roland Christen
>       Astro-Physics
>
>
>
>
>
>







Ray Gralak
 

Yanhze,

Where is ASCOM driver log? I dont use APCC, I use SGPro.
The AP V2 ASCOM driver, which you must use with SGPro, comes with a log zipper utility called "AP Log Zipper". You should be able to find it from the Windows start menu by typing that name. The utility will grab the log files for X number of days in the past. If you can't find it, you probably didn't install it when you installed the AP V2 driver. In that case, just reinstall the AP V2 driver and select the option to install it.

BTW, you can use APCC with SGPro. In fact, it is recommended. An APCC Pro license comes with your Mach2 mount, but you must contact A-P to get it.

-Ray


-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
Sent: Sunday, March 7, 2021 4:19 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Mach2 - Elongated stars

Ray,

Where is ASCOM driver log? I dont use APCC, I use SGPro.

Yanzhe

On Sun, Mar 7, 2021 at 10:45 AM Ray Gralak <iogroups@siriusimaging.com> wrote:


Hi Yanzhe,

Can you zip and post your PHD2 logs, as well as APCC/AP V2 ASCOM driver logs?

There might be something useful there.

-Ray

> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
> Sent: Sunday, March 7, 2021 10:12 AM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] Mach2 - Elongated stars
>
> Roland,
>
> I will check my mount serial number later as I just packed everything due to rain forecast.
>
> My camera's orientation was 0/180 degree, so I assume top to bottom elongation would be DEC.
>
> I dont have any picture of my setup, I just tore it down since it will be rainy this week. My setup is
> FSQ106+OAG+16803, image scale is 3.5".
> I was imaging Rosetta Nebula, after it was just past meridian for 2-3 hours.
>
> I used PHD2 drift for PA, it reported <5' PA error, I am waiting for polemaster adapter so I can confirm I get
good PA
> next time.
>
> DEC was out of balance because my setup was rear end heavy, if it was in balance position then I could
not rotate
> my CCD in all directions. My guess is that the DEC balance was off by less than 1lb. In the next test, I can
balance
> DEC to see if the issue still exists.
>
> My suspicion is that if DEC balance is off, then DEC might creep under gravity, even PA is perfect. So you
might
> see DEC continually drift then gets corrected by PHD2 periodically.
>
> Yanzhe
>
> On Sun, Mar 7, 2021 at 9:35 AM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
>
>
> Couple of questions:
>
>
> 1 - what's the mount's serial number
> 2 - which axis is the elongation
> 3 - which direction was the scope pointing (RA-Dec)
> 4 - what scope and focal length or what is the arc sec per pixel.
> 5 - do you have a picture of your setup?
>
>
>
> One comment about balance - it should be easy for you to completely balance the scope with the
clutches
> loose. Can you estimate how many lb out of balance your scope is in Dec? Normally i would not think this
would
> have any effect, but doesn't hurt to check this.
>
>
>
> Roland Christen
> Astro-Physics Inc.
>
>
>
>
> -----Original Message-----
> From: yanzhe liu <liuyanzhe@gmail.com>
> To: main@ap-gto.groups.io
> Sent: Sun, Mar 7, 2021 12:44 am
> Subject: [ap-gto] Mach2 - Elongated stars
>
>
> Testing new mach2 for a couple of nights. It works great out of the box and I am very pleased.
>
> One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
> The exact same telescope/CCD were used with another mount and stars were round, I am wondering
what I
> should check (I think there was due to some setup issue, but I could not figure it out).
> - Used OAG for guiding, so there should not be any flexure.
> - CCD orientation was 0/180 degree. The stars were elongated top to bottom.
> - I did polar alignment with PHD2 drift align. PA error should be < 5'. The field rotation of each sub is
~0.01
> degree, much larger than the other system (but elongated stars do not look like field rotation, they were
same
> across the image)
> - Both RA and DEC guiding curves looked smooth, had similar RMS. DEC correction was mainly to
one
> direction.
> - DEC balance was slightly off, camera heavy. Is Mach2 DEC sensitive to this? Will the guiding/image
be
> affected?
>
> I dont think any of the above is of particular concern, except DEC balance. Any comment/help is
appreciated.
>
> --
> Roland Christen
> Astro-Physics
>
>
>
>
>
>









yanzhe liu
 

Ray,

I am able to run "AP Log Zipper", there are 2 files shown in the app: ap.ini and Setting.apdb, however both were dated 12/29/2018. Maybe I did not enable ASCOM log.

Yanzhe

On Sun, Mar 7, 2021 at 7:37 PM Ray Gralak <iogroups@...> wrote:
Yanhze,

> Where is ASCOM driver log? I dont use APCC, I use SGPro.

The AP V2 ASCOM driver, which you must use with SGPro, comes with a log zipper utility called "AP Log Zipper". You should be able to find it from the Windows start menu by typing that name. The utility will grab the log files for X number of days in the past. If you can't find it, you probably didn't install it when you installed the AP V2 driver. In that case, just reinstall the AP V2 driver and select the option to install it.

BTW, you can use APCC with SGPro. In fact, it is recommended. An APCC Pro license comes with your Mach2 mount, but you must contact A-P to get it.

-Ray


> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
> Sent: Sunday, March 7, 2021 4:19 PM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] Mach2 - Elongated stars
>
> Ray,
>
> Where is ASCOM driver log? I dont use APCC, I use SGPro.
>
> Yanzhe
>
> On Sun, Mar 7, 2021 at 10:45 AM Ray Gralak <iogroups@...> wrote:
>
>
>       Hi Yanzhe,
>
>       Can you zip and post your PHD2 logs, as well as APCC/AP V2 ASCOM driver logs?
>
>       There might be something useful there.
>
>       -Ray
>
>       > -----Original Message-----
>       > From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
>       > Sent: Sunday, March 7, 2021 10:12 AM
>       > To: main@ap-gto.groups.io
>       > Subject: Re: [ap-gto] Mach2 - Elongated stars
>       >
>       > Roland,
>       >
>       > I will check my mount serial number later as I just packed everything due to rain forecast.
>       >
>       > My camera's orientation was 0/180 degree, so I assume top to bottom elongation would be DEC.
>       >
>       > I dont have any picture of my setup, I just tore it down since it will be rainy this week. My setup is
>       > FSQ106+OAG+16803, image scale is 3.5".
>       > I was imaging Rosetta Nebula, after it was just past meridian for 2-3 hours.
>       >
>       > I used PHD2 drift for PA, it reported <5' PA error, I am waiting for polemaster adapter so I can confirm I get
> good PA
>       > next time.
>       >
>       > DEC was out of balance because my setup was rear end heavy, if it was in balance position then I could
> not rotate
>       > my CCD in all directions. My guess is that the DEC balance was off by less than 1lb. In the next test, I can
> balance
>       > DEC to see if the issue still exists.
>       >
>       > My suspicion is that if DEC balance is off, then DEC might creep under gravity, even PA is perfect. So you
> might
>       > see DEC continually drift  then gets corrected by PHD2 periodically.
>       >
>       > Yanzhe
>       >
>       > On Sun, Mar 7, 2021 at 9:35 AM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
>       >
>       >
>       >       Couple of questions:
>       >
>       >
>       >       1 - what's the mount's serial number
>       >       2 - which axis is the elongation
>       >       3 - which direction was the scope pointing (RA-Dec)
>       >       4 - what scope and focal length or what is the arc sec per pixel.
>       >       5 - do you have a picture of your setup?
>       >
>       >
>       >
>       >       One comment about balance - it should be easy for you to completely balance the scope with the
> clutches
>       > loose. Can you estimate how many lb out of balance your scope is in Dec? Normally i would not think this
> would
>       > have any effect, but doesn't hurt to check this.
>       >
>       >
>       >
>       >       Roland Christen
>       >       Astro-Physics Inc.
>       >
>       >
>       >
>       >
>       >       -----Original Message-----
>       >       From: yanzhe liu <liuyanzhe@...>
>       >       To: main@ap-gto.groups.io
>       >       Sent: Sun, Mar 7, 2021 12:44 am
>       >       Subject: [ap-gto] Mach2 - Elongated stars
>       >
>       >
>       >       Testing new mach2 for a couple of nights. It works great out of the box and I am very pleased.
>       >
>       >       One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
>       >       The exact same telescope/CCD were used with another mount and stars were round, I am wondering
> what I
>       > should check (I think there was due to some setup issue, but I could not figure it out).
>       >       - Used OAG for guiding, so there should not be any flexure.
>       >       - CCD orientation was 0/180 degree. The stars were elongated top to bottom.
>       >       -  I did polar alignment with PHD2 drift align. PA error should be < 5'. The field rotation of each sub is
> ~0.01
>       > degree, much larger than the other system (but elongated stars do not look like field rotation, they were
> same
>       > across the image)
>       >       - Both RA and DEC guiding curves looked smooth, had similar RMS. DEC correction was mainly to
> one
>       > direction.
>       >       - DEC balance was slightly off, camera heavy. Is Mach2 DEC sensitive to this? Will the guiding/image
> be
>       > affected?
>       >
>       >       I dont think any of the above is of particular concern, except DEC balance. Any comment/help is
> appreciated.
>       >
>       >       --
>       >       Roland Christen
>       >       Astro-Physics
>       >
>       >
>       >
>       >
>       >
>       >
>
>
>
>
>
>
>
>
>







Bill Long
 

Dude there is something wrong with  your config. I literally cannot get the mount to NOT produce perfect stars. Call me if you are up and need a hand. :) 


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of yanzhe liu <liuyanzhe@...>
Sent: Wednesday, March 10, 2021 10:36 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Mach2 - Elongated stars
 
Ray,

I am able to run "AP Log Zipper", there are 2 files shown in the app: ap.ini and Setting.apdb, however both were dated 12/29/2018. Maybe I did not enable ASCOM log.

Yanzhe

On Sun, Mar 7, 2021 at 7:37 PM Ray Gralak <iogroups@...> wrote:
Yanhze,

> Where is ASCOM driver log? I dont use APCC, I use SGPro.

The AP V2 ASCOM driver, which you must use with SGPro, comes with a log zipper utility called "AP Log Zipper". You should be able to find it from the Windows start menu by typing that name. The utility will grab the log files for X number of days in the past. If you can't find it, you probably didn't install it when you installed the AP V2 driver. In that case, just reinstall the AP V2 driver and select the option to install it.

BTW, you can use APCC with SGPro. In fact, it is recommended. An APCC Pro license comes with your Mach2 mount, but you must contact A-P to get it.

-Ray


> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
> Sent: Sunday, March 7, 2021 4:19 PM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] Mach2 - Elongated stars
>
> Ray,
>
> Where is ASCOM driver log? I dont use APCC, I use SGPro.
>
> Yanzhe
>
> On Sun, Mar 7, 2021 at 10:45 AM Ray Gralak <iogroups@...> wrote:
>
>
>       Hi Yanzhe,
>
>       Can you zip and post your PHD2 logs, as well as APCC/AP V2 ASCOM driver logs?
>
>       There might be something useful there.
>
>       -Ray
>
>       > -----Original Message-----
>       > From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
>       > Sent: Sunday, March 7, 2021 10:12 AM
>       > To: main@ap-gto.groups.io
>       > Subject: Re: [ap-gto] Mach2 - Elongated stars
>       >
>       > Roland,
>       >
>       > I will check my mount serial number later as I just packed everything due to rain forecast.
>       >
>       > My camera's orientation was 0/180 degree, so I assume top to bottom elongation would be DEC.
>       >
>       > I dont have any picture of my setup, I just tore it down since it will be rainy this week. My setup is
>       > FSQ106+OAG+16803, image scale is 3.5".
>       > I was imaging Rosetta Nebula, after it was just past meridian for 2-3 hours.
>       >
>       > I used PHD2 drift for PA, it reported <5' PA error, I am waiting for polemaster adapter so I can confirm I get
> good PA
>       > next time.
>       >
>       > DEC was out of balance because my setup was rear end heavy, if it was in balance position then I could
> not rotate
>       > my CCD in all directions. My guess is that the DEC balance was off by less than 1lb. In the next test, I can
> balance
>       > DEC to see if the issue still exists.
>       >
>       > My suspicion is that if DEC balance is off, then DEC might creep under gravity, even PA is perfect. So you
> might
>       > see DEC continually drift  then gets corrected by PHD2 periodically.
>       >
>       > Yanzhe
>       >
>       > On Sun, Mar 7, 2021 at 9:35 AM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
>       >
>       >
>       >       Couple of questions:
>       >
>       >
>       >       1 - what's the mount's serial number
>       >       2 - which axis is the elongation
>       >       3 - which direction was the scope pointing (RA-Dec)
>       >       4 - what scope and focal length or what is the arc sec per pixel.
>       >       5 - do you have a picture of your setup?
>       >
>       >
>       >
>       >       One comment about balance - it should be easy for you to completely balance the scope with the
> clutches
>       > loose. Can you estimate how many lb out of balance your scope is in Dec? Normally i would not think this
> would
>       > have any effect, but doesn't hurt to check this.
>       >
>       >
>       >
>       >       Roland Christen
>       >       Astro-Physics Inc.
>       >
>       >
>       >
>       >
>       >       -----Original Message-----
>       >       From: yanzhe liu <liuyanzhe@...>
>       >       To: main@ap-gto.groups.io
>       >       Sent: Sun, Mar 7, 2021 12:44 am
>       >       Subject: [ap-gto] Mach2 - Elongated stars
>       >
>       >
>       >       Testing new mach2 for a couple of nights. It works great out of the box and I am very pleased.
>       >
>       >       One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
>       >       The exact same telescope/CCD were used with another mount and stars were round, I am wondering
> what I
>       > should check (I think there was due to some setup issue, but I could not figure it out).
>       >       - Used OAG for guiding, so there should not be any flexure.
>       >       - CCD orientation was 0/180 degree. The stars were elongated top to bottom.
>       >       -  I did polar alignment with PHD2 drift align. PA error should be < 5'. The field rotation of each sub is
> ~0.01
>       > degree, much larger than the other system (but elongated stars do not look like field rotation, they were
> same
>       > across the image)
>       >       - Both RA and DEC guiding curves looked smooth, had similar RMS. DEC correction was mainly to
> one
>       > direction.
>       >       - DEC balance was slightly off, camera heavy. Is Mach2 DEC sensitive to this? Will the guiding/image
> be
>       > affected?
>       >
>       >       I dont think any of the above is of particular concern, except DEC balance. Any comment/help is
> appreciated.
>       >
>       >       --
>       >       Roland Christen
>       >       Astro-Physics
>       >
>       >
>       >
>       >
>       >
>       >
>
>
>
>
>
>
>
>
>







Roland Christen
 

hello Yanzhe,

I have done some more digging and testing with regard to your guiding results. You had said that your Dec axis is not balanced. Unbalance puts strain on the worm teeth which increases friction and can inhibit smooth motion at the sub-arc sec level. For example, a 1 lb unbalance at 30 inches distance produces 10lb of pressure on the worm teeth. The resulting friction is then 10 times what it would be if the axis was properly balanced. High static friction on the Dec axis causes stick-slip motion as the axis is being nudged along in small steps during a typical guiding run. 

In RA the unbalance is not as critical because the worm is constantly turning, and the dynamic friction is much lower than the static friction of the Dec axis.

We made the Mach2 with clutches that can be loosened to achieve good balance. If you fully loosen the Dec knobs with the mount in Park 4 or 5 position, it should be balanced enough to not move on its own. It should feel light in both directions and stay put when you let go of the scope. Try to get at least this much balance on your rig, and you will see that it will guide exceptionally well and give you the performance that you want.

Rolando



-----Original Message-----
From: yanzhe liu <liuyanzhe@...>
To: main@ap-gto.groups.io
Sent: Thu, Mar 11, 2021 12:36 am
Subject: Re: [ap-gto] Mach2 - Elongated stars

Ray,

I am able to run "AP Log Zipper", there are 2 files shown in the app: ap.ini and Setting.apdb, however both were dated 12/29/2018. Maybe I did not enable ASCOM log.

Yanzhe

On Sun, Mar 7, 2021 at 7:37 PM Ray Gralak <iogroups@...> wrote:
Yanhze,

> Where is ASCOM driver log? I dont use APCC, I use SGPro.

The AP V2 ASCOM driver, which you must use with SGPro, comes with a log zipper utility called "AP Log Zipper". You should be able to find it from the Windows start menu by typing that name. The utility will grab the log files for X number of days in the past. If you can't find it, you probably didn't install it when you installed the AP V2 driver. In that case, just reinstall the AP V2 driver and select the option to install it.

BTW, you can use APCC with SGPro. In fact, it is recommended. An APCC Pro license comes with your Mach2 mount, but you must contact A-P to get it.

-Ray


> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
> Sent: Sunday, March 7, 2021 4:19 PM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] Mach2 - Elongated stars
>
> Ray,
>
> Where is ASCOM driver log? I dont use APCC, I use SGPro.
>
> Yanzhe
>
> On Sun, Mar 7, 2021 at 10:45 AM Ray Gralak <iogroups@...> wrote:
>
>
>       Hi Yanzhe,
>
>       Can you zip and post your PHD2 logs, as well as APCC/AP V2 ASCOM driver logs?
>
>       There might be something useful there.
>
>       -Ray
>
>       > -----Original Message-----
>       > From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
>       > Sent: Sunday, March 7, 2021 10:12 AM
>       > To: main@ap-gto.groups.io
>       > Subject: Re: [ap-gto] Mach2 - Elongated stars
>       >
>       > Roland,
>       >
>       > I will check my mount serial number later as I just packed everything due to rain forecast.
>       >
>       > My camera's orientation was 0/180 degree, so I assume top to bottom elongation would be DEC.
>       >
>       > I dont have any picture of my setup, I just tore it down since it will be rainy this week. My setup is
>       > FSQ106+OAG+16803, image scale is 3.5".
>       > I was imaging Rosetta Nebula, after it was just past meridian for 2-3 hours.
>       >
>       > I used PHD2 drift for PA, it reported <5' PA error, I am waiting for polemaster adapter so I can confirm I get
> good PA
>       > next time.
>       >
>       > DEC was out of balance because my setup was rear end heavy, if it was in balance position then I could
> not rotate
>       > my CCD in all directions. My guess is that the DEC balance was off by less than 1lb. In the next test, I can
> balance
>       > DEC to see if the issue still exists.
>       >
>       > My suspicion is that if DEC balance is off, then DEC might creep under gravity, even PA is perfect. So you
> might
>       > see DEC continually drift  then gets corrected by PHD2 periodically.
>       >
>       > Yanzhe
>       >
>       > On Sun, Mar 7, 2021 at 9:35 AM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
>       >
>       >
>       >       Couple of questions:
>       >
>       >
>       >       1 - what's the mount's serial number
>       >       2 - which axis is the elongation
>       >       3 - which direction was the scope pointing (RA-Dec)
>       >       4 - what scope and focal length or what is the arc sec per pixel.
>       >       5 - do you have a picture of your setup?
>       >
>       >
>       >
>       >       One comment about balance - it should be easy for you to completely balance the scope with the
> clutches
>       > loose. Can you estimate how many lb out of balance your scope is in Dec? Normally i would not think this
> would
>       > have any effect, but doesn't hurt to check this.
>       >
>       >
>       >
>       >       Roland Christen
>       >       Astro-Physics Inc.
>       >
>       >
>       >
>       >
>       >       -----Original Message-----
>       >       From: yanzhe liu <liuyanzhe@...>
>       >       To: main@ap-gto.groups.io
>       >       Sent: Sun, Mar 7, 2021 12:44 am
>       >       Subject: [ap-gto] Mach2 - Elongated stars
>       >
>       >
>       >       Testing new mach2 for a couple of nights. It works great out of the box and I am very pleased.
>       >
>       >       One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
>       >       The exact same telescope/CCD were used with another mount and stars were round, I am wondering
> what I
>       > should check (I think there was due to some setup issue, but I could not figure it out).
>       >       - Used OAG for guiding, so there should not be any flexure.
>       >       - CCD orientation was 0/180 degree. The stars were elongated top to bottom.
>       >       -  I did polar alignment with PHD2 drift align. PA error should be < 5'. The field rotation of each sub is
> ~0.01
>       > degree, much larger than the other system (but elongated stars do not look like field rotation, they were
> same
>       > across the image)
>       >       - Both RA and DEC guiding curves looked smooth, had similar RMS. DEC correction was mainly to
> one
>       > direction.
>       >       - DEC balance was slightly off, camera heavy. Is Mach2 DEC sensitive to this? Will the guiding/image
> be
>       > affected?
>       >
>       >       I dont think any of the above is of particular concern, except DEC balance. Any comment/help is
> appreciated.
>       >
>       >       --
>       >       Roland Christen
>       >       Astro-Physics
>       >
>       >
>       >
>       >
>       >
>       >
>
>
>
>
>
>
>
>
>







--
Roland Christen
Astro-Physics


Ray Gralak
 

Yanzhe,

I am able to run "AP Log Zipper", there are 2 files shown in the app: ap.ini and Setting.apdb, however both were dated
12/29/2018. Maybe I did not enable ASCOM log.
Hmmm... that is not the default. Did you happen to use this computer with another A-P mount in the past?

Since it is probably a small file, please attach that zip file to a post. It's worth checking the settings to see if anything stands out as an incorrect setting.

BTW, can you also provide a dropbox or google drive link to one of the single raw FITS images with the elongated stars? It's important that it is an unprocessed image and not a jpeg or stacked with other images.

Thanks,

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
Sent: Wednesday, March 10, 2021 10:36 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Mach2 - Elongated stars

Ray,

I am able to run "AP Log Zipper", there are 2 files shown in the app: ap.ini and Setting.apdb, however both were dated
12/29/2018. Maybe I did not enable ASCOM log.

Yanzhe

On Sun, Mar 7, 2021 at 7:37 PM Ray Gralak <iogroups@siriusimaging.com> wrote:


Yanhze,

> Where is ASCOM driver log? I dont use APCC, I use SGPro.

The AP V2 ASCOM driver, which you must use with SGPro, comes with a log zipper utility called "AP Log
Zipper". You should be able to find it from the Windows start menu by typing that name. The utility will grab the log files
for X number of days in the past. If you can't find it, you probably didn't install it when you installed the AP V2 driver. In
that case, just reinstall the AP V2 driver and select the option to install it.

BTW, you can use APCC with SGPro. In fact, it is recommended. An APCC Pro license comes with your
Mach2 mount, but you must contact A-P to get it.

-Ray


> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
> Sent: Sunday, March 7, 2021 4:19 PM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] Mach2 - Elongated stars
>
> Ray,
>
> Where is ASCOM driver log? I dont use APCC, I use SGPro.
>
> Yanzhe
>
> On Sun, Mar 7, 2021 at 10:45 AM Ray Gralak <iogroups@siriusimaging.com> wrote:
>
>
> Hi Yanzhe,
>
> Can you zip and post your PHD2 logs, as well as APCC/AP V2 ASCOM driver logs?
>
> There might be something useful there.
>
> -Ray
>
> > -----Original Message-----
> > From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
> > Sent: Sunday, March 7, 2021 10:12 AM
> > To: main@ap-gto.groups.io
> > Subject: Re: [ap-gto] Mach2 - Elongated stars
> >
> > Roland,
> >
> > I will check my mount serial number later as I just packed everything due to rain forecast.
> >
> > My camera's orientation was 0/180 degree, so I assume top to bottom elongation would be DEC.
> >
> > I dont have any picture of my setup, I just tore it down since it will be rainy this week. My setup is
> > FSQ106+OAG+16803, image scale is 3.5".
> > I was imaging Rosetta Nebula, after it was just past meridian for 2-3 hours.
> >
> > I used PHD2 drift for PA, it reported <5' PA error, I am waiting for polemaster adapter so I can confirm I
get
> good PA
> > next time.
> >
> > DEC was out of balance because my setup was rear end heavy, if it was in balance position then I
could
> not rotate
> > my CCD in all directions. My guess is that the DEC balance was off by less than 1lb. In the next test, I
can
> balance
> > DEC to see if the issue still exists.
> >
> > My suspicion is that if DEC balance is off, then DEC might creep under gravity, even PA is perfect. So
you
> might
> > see DEC continually drift then gets corrected by PHD2 periodically.
> >
> > Yanzhe
> >
> > On Sun, Mar 7, 2021 at 9:35 AM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
> >
> >
> > Couple of questions:
> >
> >
> > 1 - what's the mount's serial number
> > 2 - which axis is the elongation
> > 3 - which direction was the scope pointing (RA-Dec)
> > 4 - what scope and focal length or what is the arc sec per pixel.
> > 5 - do you have a picture of your setup?
> >
> >
> >
> > One comment about balance - it should be easy for you to completely balance the scope with the
> clutches
> > loose. Can you estimate how many lb out of balance your scope is in Dec? Normally i would not think
this
> would
> > have any effect, but doesn't hurt to check this.
> >
> >
> >
> > Roland Christen
> > Astro-Physics Inc.
> >
> >
> >
> >
> > -----Original Message-----
> > From: yanzhe liu <liuyanzhe@gmail.com>
> > To: main@ap-gto.groups.io
> > Sent: Sun, Mar 7, 2021 12:44 am
> > Subject: [ap-gto] Mach2 - Elongated stars
> >
> >
> > Testing new mach2 for a couple of nights. It works great out of the box and I am very pleased.
> >
> > One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
> > The exact same telescope/CCD were used with another mount and stars were round, I am
wondering
> what I
> > should check (I think there was due to some setup issue, but I could not figure it out).
> > - Used OAG for guiding, so there should not be any flexure.
> > - CCD orientation was 0/180 degree. The stars were elongated top to bottom.
> > - I did polar alignment with PHD2 drift align. PA error should be < 5'. The field rotation of each sub
is
> ~0.01
> > degree, much larger than the other system (but elongated stars do not look like field rotation, they were
> same
> > across the image)
> > - Both RA and DEC guiding curves looked smooth, had similar RMS. DEC correction was mainly to
> one
> > direction.
> > - DEC balance was slightly off, camera heavy. Is Mach2 DEC sensitive to this? Will the
guiding/image
> be
> > affected?
> >
> > I dont think any of the above is of particular concern, except DEC balance. Any comment/help is
> appreciated.
> >
> > --
> > Roland Christen
> > Astro-Physics
> >
> >
> >
> >
> >
> >
>
>
>
>
>
>
>
>
>









Bill Long
 

I did notice a huge difference in using the clutches to balance versus my Mach 1 I had. On my Mach 1 the DEC axis was always really hard to feel out in terms of balance. The Mach 2 is very much like it's bigger brother the 1100. Easy to balance and the clutch knobs on the Mach 2 are really well placed and easy to work with. 


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Roland Christen via groups.io <chris1011@...>
Sent: Thursday, March 11, 2021 7:35 AM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Mach2 - Elongated stars
 
hello Yanzhe,

I have done some more digging and testing with regard to your guiding results. You had said that your Dec axis is not balanced. Unbalance puts strain on the worm teeth which increases friction and can inhibit smooth motion at the sub-arc sec level. For example, a 1 lb unbalance at 30 inches distance produces 10lb of pressure on the worm teeth. The resulting friction is then 10 times what it would be if the axis was properly balanced. High static friction on the Dec axis causes stick-slip motion as the axis is being nudged along in small steps during a typical guiding run. 

In RA the unbalance is not as critical because the worm is constantly turning, and the dynamic friction is much lower than the static friction of the Dec axis.

We made the Mach2 with clutches that can be loosened to achieve good balance. If you fully loosen the Dec knobs with the mount in Park 4 or 5 position, it should be balanced enough to not move on its own. It should feel light in both directions and stay put when you let go of the scope. Try to get at least this much balance on your rig, and you will see that it will guide exceptionally well and give you the performance that you want.

Rolando



-----Original Message-----
From: yanzhe liu <liuyanzhe@...>
To: main@ap-gto.groups.io
Sent: Thu, Mar 11, 2021 12:36 am
Subject: Re: [ap-gto] Mach2 - Elongated stars

Ray,

I am able to run "AP Log Zipper", there are 2 files shown in the app: ap.ini and Setting.apdb, however both were dated 12/29/2018. Maybe I did not enable ASCOM log.

Yanzhe

On Sun, Mar 7, 2021 at 7:37 PM Ray Gralak <iogroups@...> wrote:
Yanhze,

> Where is ASCOM driver log? I dont use APCC, I use SGPro.

The AP V2 ASCOM driver, which you must use with SGPro, comes with a log zipper utility called "AP Log Zipper". You should be able to find it from the Windows start menu by typing that name. The utility will grab the log files for X number of days in the past. If you can't find it, you probably didn't install it when you installed the AP V2 driver. In that case, just reinstall the AP V2 driver and select the option to install it.

BTW, you can use APCC with SGPro. In fact, it is recommended. An APCC Pro license comes with your Mach2 mount, but you must contact A-P to get it.

-Ray


> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
> Sent: Sunday, March 7, 2021 4:19 PM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] Mach2 - Elongated stars
>
> Ray,
>
> Where is ASCOM driver log? I dont use APCC, I use SGPro.
>
> Yanzhe
>
> On Sun, Mar 7, 2021 at 10:45 AM Ray Gralak <iogroups@...> wrote:
>
>
>       Hi Yanzhe,
>
>       Can you zip and post your PHD2 logs, as well as APCC/AP V2 ASCOM driver logs?
>
>       There might be something useful there.
>
>       -Ray
>
>       > -----Original Message-----
>       > From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
>       > Sent: Sunday, March 7, 2021 10:12 AM
>       > To: main@ap-gto.groups.io
>       > Subject: Re: [ap-gto] Mach2 - Elongated stars
>       >
>       > Roland,
>       >
>       > I will check my mount serial number later as I just packed everything due to rain forecast.
>       >
>       > My camera's orientation was 0/180 degree, so I assume top to bottom elongation would be DEC.
>       >
>       > I dont have any picture of my setup, I just tore it down since it will be rainy this week. My setup is
>       > FSQ106+OAG+16803, image scale is 3.5".
>       > I was imaging Rosetta Nebula, after it was just past meridian for 2-3 hours.
>       >
>       > I used PHD2 drift for PA, it reported <5' PA error, I am waiting for polemaster adapter so I can confirm I get
> good PA
>       > next time.
>       >
>       > DEC was out of balance because my setup was rear end heavy, if it was in balance position then I could
> not rotate
>       > my CCD in all directions. My guess is that the DEC balance was off by less than 1lb. In the next test, I can
> balance
>       > DEC to see if the issue still exists.
>       >
>       > My suspicion is that if DEC balance is off, then DEC might creep under gravity, even PA is perfect. So you
> might
>       > see DEC continually drift  then gets corrected by PHD2 periodically.
>       >
>       > Yanzhe
>       >
>       > On Sun, Mar 7, 2021 at 9:35 AM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
>       >
>       >
>       >       Couple of questions:
>       >
>       >
>       >       1 - what's the mount's serial number
>       >       2 - which axis is the elongation
>       >       3 - which direction was the scope pointing (RA-Dec)
>       >       4 - what scope and focal length or what is the arc sec per pixel.
>       >       5 - do you have a picture of your setup?
>       >
>       >
>       >
>       >       One comment about balance - it should be easy for you to completely balance the scope with the
> clutches
>       > loose. Can you estimate how many lb out of balance your scope is in Dec? Normally i would not think this
> would
>       > have any effect, but doesn't hurt to check this.
>       >
>       >
>       >
>       >       Roland Christen
>       >       Astro-Physics Inc.
>       >
>       >
>       >
>       >
>       >       -----Original Message-----
>       >       From: yanzhe liu <liuyanzhe@...>
>       >       To: main@ap-gto.groups.io
>       >       Sent: Sun, Mar 7, 2021 12:44 am
>       >       Subject: [ap-gto] Mach2 - Elongated stars
>       >
>       >
>       >       Testing new mach2 for a couple of nights. It works great out of the box and I am very pleased.
>       >
>       >       One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
>       >       The exact same telescope/CCD were used with another mount and stars were round, I am wondering
> what I
>       > should check (I think there was due to some setup issue, but I could not figure it out).
>       >       - Used OAG for guiding, so there should not be any flexure.
>       >       - CCD orientation was 0/180 degree. The stars were elongated top to bottom.
>       >       -  I did polar alignment with PHD2 drift align. PA error should be < 5'. The field rotation of each sub is
> ~0.01
>       > degree, much larger than the other system (but elongated stars do not look like field rotation, they were
> same
>       > across the image)
>       >       - Both RA and DEC guiding curves looked smooth, had similar RMS. DEC correction was mainly to
> one
>       > direction.
>       >       - DEC balance was slightly off, camera heavy. Is Mach2 DEC sensitive to this? Will the guiding/image
> be
>       > affected?
>       >
>       >       I dont think any of the above is of particular concern, except DEC balance. Any comment/help is
> appreciated.
>       >
>       >       --
>       >       Roland Christen
>       >       Astro-Physics
>       >
>       >
>       >
>       >
>       >
>       >
>
>
>
>
>
>
>
>
>







--
Roland Christen
Astro-Physics


yanzhe liu
 

Agree, I never had any issue with mach1 and 1100, so I think I must have made a mistake here.


On Thu, Mar 11, 2021 at 12:10 AM Bill Long <bill@...> wrote:
Dude there is something wrong with  your config. I literally cannot get the mount to NOT produce perfect stars. Call me if you are up and need a hand. :) 


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of yanzhe liu <liuyanzhe@...>
Sent: Wednesday, March 10, 2021 10:36 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Mach2 - Elongated stars
 
Ray,

I am able to run "AP Log Zipper", there are 2 files shown in the app: ap.ini and Setting.apdb, however both were dated 12/29/2018. Maybe I did not enable ASCOM log.

Yanzhe

On Sun, Mar 7, 2021 at 7:37 PM Ray Gralak <iogroups@...> wrote:
Yanhze,

> Where is ASCOM driver log? I dont use APCC, I use SGPro.

The AP V2 ASCOM driver, which you must use with SGPro, comes with a log zipper utility called "AP Log Zipper". You should be able to find it from the Windows start menu by typing that name. The utility will grab the log files for X number of days in the past. If you can't find it, you probably didn't install it when you installed the AP V2 driver. In that case, just reinstall the AP V2 driver and select the option to install it.

BTW, you can use APCC with SGPro. In fact, it is recommended. An APCC Pro license comes with your Mach2 mount, but you must contact A-P to get it.

-Ray


> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
> Sent: Sunday, March 7, 2021 4:19 PM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] Mach2 - Elongated stars
>
> Ray,
>
> Where is ASCOM driver log? I dont use APCC, I use SGPro.
>
> Yanzhe
>
> On Sun, Mar 7, 2021 at 10:45 AM Ray Gralak <iogroups@...> wrote:
>
>
>       Hi Yanzhe,
>
>       Can you zip and post your PHD2 logs, as well as APCC/AP V2 ASCOM driver logs?
>
>       There might be something useful there.
>
>       -Ray
>
>       > -----Original Message-----
>       > From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
>       > Sent: Sunday, March 7, 2021 10:12 AM
>       > To: main@ap-gto.groups.io
>       > Subject: Re: [ap-gto] Mach2 - Elongated stars
>       >
>       > Roland,
>       >
>       > I will check my mount serial number later as I just packed everything due to rain forecast.
>       >
>       > My camera's orientation was 0/180 degree, so I assume top to bottom elongation would be DEC.
>       >
>       > I dont have any picture of my setup, I just tore it down since it will be rainy this week. My setup is
>       > FSQ106+OAG+16803, image scale is 3.5".
>       > I was imaging Rosetta Nebula, after it was just past meridian for 2-3 hours.
>       >
>       > I used PHD2 drift for PA, it reported <5' PA error, I am waiting for polemaster adapter so I can confirm I get
> good PA
>       > next time.
>       >
>       > DEC was out of balance because my setup was rear end heavy, if it was in balance position then I could
> not rotate
>       > my CCD in all directions. My guess is that the DEC balance was off by less than 1lb. In the next test, I can
> balance
>       > DEC to see if the issue still exists.
>       >
>       > My suspicion is that if DEC balance is off, then DEC might creep under gravity, even PA is perfect. So you
> might
>       > see DEC continually drift  then gets corrected by PHD2 periodically.
>       >
>       > Yanzhe
>       >
>       > On Sun, Mar 7, 2021 at 9:35 AM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
>       >
>       >
>       >       Couple of questions:
>       >
>       >
>       >       1 - what's the mount's serial number
>       >       2 - which axis is the elongation
>       >       3 - which direction was the scope pointing (RA-Dec)
>       >       4 - what scope and focal length or what is the arc sec per pixel.
>       >       5 - do you have a picture of your setup?
>       >
>       >
>       >
>       >       One comment about balance - it should be easy for you to completely balance the scope with the
> clutches
>       > loose. Can you estimate how many lb out of balance your scope is in Dec? Normally i would not think this
> would
>       > have any effect, but doesn't hurt to check this.
>       >
>       >
>       >
>       >       Roland Christen
>       >       Astro-Physics Inc.
>       >
>       >
>       >
>       >
>       >       -----Original Message-----
>       >       From: yanzhe liu <liuyanzhe@...>
>       >       To: main@ap-gto.groups.io
>       >       Sent: Sun, Mar 7, 2021 12:44 am
>       >       Subject: [ap-gto] Mach2 - Elongated stars
>       >
>       >
>       >       Testing new mach2 for a couple of nights. It works great out of the box and I am very pleased.
>       >
>       >       One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
>       >       The exact same telescope/CCD were used with another mount and stars were round, I am wondering
> what I
>       > should check (I think there was due to some setup issue, but I could not figure it out).
>       >       - Used OAG for guiding, so there should not be any flexure.
>       >       - CCD orientation was 0/180 degree. The stars were elongated top to bottom.
>       >       -  I did polar alignment with PHD2 drift align. PA error should be < 5'. The field rotation of each sub is
> ~0.01
>       > degree, much larger than the other system (but elongated stars do not look like field rotation, they were
> same
>       > across the image)
>       >       - Both RA and DEC guiding curves looked smooth, had similar RMS. DEC correction was mainly to
> one
>       > direction.
>       >       - DEC balance was slightly off, camera heavy. Is Mach2 DEC sensitive to this? Will the guiding/image
> be
>       > affected?
>       >
>       >       I dont think any of the above is of particular concern, except DEC balance. Any comment/help is
> appreciated.
>       >
>       >       --
>       >       Roland Christen
>       >       Astro-Physics
>       >
>       >
>       >
>       >
>       >
>       >
>
>
>
>
>
>
>
>
>







yanzhe liu
 

I have been using mach1 and 1100 prior to mach2. I knew I changed mount to mach2 in ascom driver.

Let me try again with balanced DEC, as suggested by Roland, to see if the issue is going away.  

On Thu, Mar 11, 2021 at 7:38 AM Ray Gralak <iogroups@...> wrote:
Yanzhe,

> I am able to run "AP Log Zipper", there are 2 files shown in the app: ap.ini and Setting.apdb, however both were dated
> 12/29/2018. Maybe I did not enable ASCOM log.

Hmmm... that is not the default. Did you happen to use this computer with another A-P mount in the past?

Since it is probably a small file, please attach that zip file to a post. It's worth checking the settings to see if anything stands out as an incorrect setting.

BTW, can you also provide a dropbox or google drive link to one of the single raw FITS images with the elongated stars? It's important that it is an unprocessed image and not a jpeg or stacked with other images.

Thanks,

-Ray

> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
> Sent: Wednesday, March 10, 2021 10:36 PM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] Mach2 - Elongated stars
>
> Ray,
>
> I am able to run "AP Log Zipper", there are 2 files shown in the app: ap.ini and Setting.apdb, however both were dated
> 12/29/2018. Maybe I did not enable ASCOM log.
>
> Yanzhe
>
> On Sun, Mar 7, 2021 at 7:37 PM Ray Gralak <iogroups@...> wrote:
>
>
>       Yanhze,
>
>       > Where is ASCOM driver log? I dont use APCC, I use SGPro.
>
>       The AP V2 ASCOM driver, which you must use with SGPro, comes with a log zipper utility called "AP Log
> Zipper". You should be able to find it from the Windows start menu by typing that name. The utility will grab the log files
> for X number of days in the past. If you can't find it, you probably didn't install it when you installed the AP V2 driver. In
> that case, just reinstall the AP V2 driver and select the option to install it.
>
>       BTW, you can use APCC with SGPro. In fact, it is recommended. An APCC Pro license comes with your
> Mach2 mount, but you must contact A-P to get it.
>
>       -Ray
>
>
>       > -----Original Message-----
>       > From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
>       > Sent: Sunday, March 7, 2021 4:19 PM
>       > To: main@ap-gto.groups.io
>       > Subject: Re: [ap-gto] Mach2 - Elongated stars
>       >
>       > Ray,
>       >
>       > Where is ASCOM driver log? I dont use APCC, I use SGPro.
>       >
>       > Yanzhe
>       >
>       > On Sun, Mar 7, 2021 at 10:45 AM Ray Gralak <iogroups@...> wrote:
>       >
>       >
>       >       Hi Yanzhe,
>       >
>       >       Can you zip and post your PHD2 logs, as well as APCC/AP V2 ASCOM driver logs?
>       >
>       >       There might be something useful there.
>       >
>       >       -Ray
>       >
>       >       > -----Original Message-----
>       >       > From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
>       >       > Sent: Sunday, March 7, 2021 10:12 AM
>       >       > To: main@ap-gto.groups.io
>       >       > Subject: Re: [ap-gto] Mach2 - Elongated stars
>       >       >
>       >       > Roland,
>       >       >
>       >       > I will check my mount serial number later as I just packed everything due to rain forecast.
>       >       >
>       >       > My camera's orientation was 0/180 degree, so I assume top to bottom elongation would be DEC.
>       >       >
>       >       > I dont have any picture of my setup, I just tore it down since it will be rainy this week. My setup is
>       >       > FSQ106+OAG+16803, image scale is 3.5".
>       >       > I was imaging Rosetta Nebula, after it was just past meridian for 2-3 hours.
>       >       >
>       >       > I used PHD2 drift for PA, it reported <5' PA error, I am waiting for polemaster adapter so I can confirm I
> get
>       > good PA
>       >       > next time.
>       >       >
>       >       > DEC was out of balance because my setup was rear end heavy, if it was in balance position then I
> could
>       > not rotate
>       >       > my CCD in all directions. My guess is that the DEC balance was off by less than 1lb. In the next test, I
> can
>       > balance
>       >       > DEC to see if the issue still exists.
>       >       >
>       >       > My suspicion is that if DEC balance is off, then DEC might creep under gravity, even PA is perfect. So
> you
>       > might
>       >       > see DEC continually drift  then gets corrected by PHD2 periodically.
>       >       >
>       >       > Yanzhe
>       >       >
>       >       > On Sun, Mar 7, 2021 at 9:35 AM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
>       >       >
>       >       >
>       >       >       Couple of questions:
>       >       >
>       >       >
>       >       >       1 - what's the mount's serial number
>       >       >       2 - which axis is the elongation
>       >       >       3 - which direction was the scope pointing (RA-Dec)
>       >       >       4 - what scope and focal length or what is the arc sec per pixel.
>       >       >       5 - do you have a picture of your setup?
>       >       >
>       >       >
>       >       >
>       >       >       One comment about balance - it should be easy for you to completely balance the scope with the
>       > clutches
>       >       > loose. Can you estimate how many lb out of balance your scope is in Dec? Normally i would not think
> this
>       > would
>       >       > have any effect, but doesn't hurt to check this.
>       >       >
>       >       >
>       >       >
>       >       >       Roland Christen
>       >       >       Astro-Physics Inc.
>       >       >
>       >       >
>       >       >
>       >       >
>       >       >       -----Original Message-----
>       >       >       From: yanzhe liu <liuyanzhe@...>
>       >       >       To: main@ap-gto.groups.io
>       >       >       Sent: Sun, Mar 7, 2021 12:44 am
>       >       >       Subject: [ap-gto] Mach2 - Elongated stars
>       >       >
>       >       >
>       >       >       Testing new mach2 for a couple of nights. It works great out of the box and I am very pleased.
>       >       >
>       >       >       One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
>       >       >       The exact same telescope/CCD were used with another mount and stars were round, I am
> wondering
>       > what I
>       >       > should check (I think there was due to some setup issue, but I could not figure it out).
>       >       >       - Used OAG for guiding, so there should not be any flexure.
>       >       >       - CCD orientation was 0/180 degree. The stars were elongated top to bottom.
>       >       >       -  I did polar alignment with PHD2 drift align. PA error should be < 5'. The field rotation of each sub
> is
>       > ~0.01
>       >       > degree, much larger than the other system (but elongated stars do not look like field rotation, they were
>       > same
>       >       > across the image)
>       >       >       - Both RA and DEC guiding curves looked smooth, had similar RMS. DEC correction was mainly to
>       > one
>       >       > direction.
>       >       >       - DEC balance was slightly off, camera heavy. Is Mach2 DEC sensitive to this? Will the
> guiding/image
>       > be
>       >       > affected?
>       >       >
>       >       >       I dont think any of the above is of particular concern, except DEC balance. Any comment/help is
>       > appreciated.
>       >       >
>       >       >       --
>       >       >       Roland Christen
>       >       >       Astro-Physics
>       >       >
>       >       >
>       >       >
>       >       >
>       >       >
>       >       >
>       >
>       >
>       >
>       >
>       >
>       >
>       >
>       >
>       >
>
>
>
>
>
>
>
>
>







Roland Christen
 

Please post a screen shot of the guider graph with corrections showing, and all other details. From that I can tell you if there is anything going on with the mount.

Rolando



-----Original Message-----
From: yanzhe liu <liuyanzhe@...>
To: main@ap-gto.groups.io
Sent: Fri, Mar 12, 2021 4:41 pm
Subject: Re: [ap-gto] Mach2 - Elongated stars

I have been using mach1 and 1100 prior to mach2. I knew I changed mount to mach2 in ascom driver.

Let me try again with balanced DEC, as suggested by Roland, to see if the issue is going away.  

On Thu, Mar 11, 2021 at 7:38 AM Ray Gralak <iogroups@...> wrote:
Yanzhe,

> I am able to run "AP Log Zipper", there are 2 files shown in the app: ap.ini and Setting.apdb, however both were dated
> 12/29/2018. Maybe I did not enable ASCOM log.

Hmmm... that is not the default. Did you happen to use this computer with another A-P mount in the past?

Since it is probably a small file, please attach that zip file to a post. It's worth checking the settings to see if anything stands out as an incorrect setting.

BTW, can you also provide a dropbox or google drive link to one of the single raw FITS images with the elongated stars? It's important that it is an unprocessed image and not a jpeg or stacked with other images.

Thanks,

-Ray

> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
> Sent: Wednesday, March 10, 2021 10:36 PM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] Mach2 - Elongated stars
>
> Ray,
>
> I am able to run "AP Log Zipper", there are 2 files shown in the app: ap.ini and Setting.apdb, however both were dated
> 12/29/2018. Maybe I did not enable ASCOM log.
>
> Yanzhe
>
> On Sun, Mar 7, 2021 at 7:37 PM Ray Gralak <iogroups@...> wrote:
>
>
>       Yanhze,
>
>       > Where is ASCOM driver log? I dont use APCC, I use SGPro.
>
>       The AP V2 ASCOM driver, which you must use with SGPro, comes with a log zipper utility called "AP Log
> Zipper". You should be able to find it from the Windows start menu by typing that name. The utility will grab the log files
> for X number of days in the past. If you can't find it, you probably didn't install it when you installed the AP V2 driver. In
> that case, just reinstall the AP V2 driver and select the option to install it.
>
>       BTW, you can use APCC with SGPro. In fact, it is recommended. An APCC Pro license comes with your
> Mach2 mount, but you must contact A-P to get it.
>
>       -Ray
>
>
>       > -----Original Message-----
>       > From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
>       > Sent: Sunday, March 7, 2021 4:19 PM
>       > To: main@ap-gto.groups.io
>       > Subject: Re: [ap-gto] Mach2 - Elongated stars
>       >
>       > Ray,
>       >
>       > Where is ASCOM driver log? I dont use APCC, I use SGPro.
>       >
>       > Yanzhe
>       >
>       > On Sun, Mar 7, 2021 at 10:45 AM Ray Gralak <iogroups@...> wrote:
>       >
>       >
>       >       Hi Yanzhe,
>       >
>       >       Can you zip and post your PHD2 logs, as well as APCC/AP V2 ASCOM driver logs?
>       >
>       >       There might be something useful there.
>       >
>       >       -Ray
>       >
>       >       > -----Original Message-----
>       >       > From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of yanzhe liu
>       >       > Sent: Sunday, March 7, 2021 10:12 AM
>       >       > To: main@ap-gto.groups.io
>       >       > Subject: Re: [ap-gto] Mach2 - Elongated stars
>       >       >
>       >       > Roland,
>       >       >
>       >       > I will check my mount serial number later as I just packed everything due to rain forecast.
>       >       >
>       >       > My camera's orientation was 0/180 degree, so I assume top to bottom elongation would be DEC.
>       >       >
>       >       > I dont have any picture of my setup, I just tore it down since it will be rainy this week. My setup is
>       >       > FSQ106+OAG+16803, image scale is 3.5".
>       >       > I was imaging Rosetta Nebula, after it was just past meridian for 2-3 hours.
>       >       >
>       >       > I used PHD2 drift for PA, it reported <5' PA error, I am waiting for polemaster adapter so I can confirm I
> get
>       > good PA
>       >       > next time.
>       >       >
>       >       > DEC was out of balance because my setup was rear end heavy, if it was in balance position then I
> could
>       > not rotate
>       >       > my CCD in all directions. My guess is that the DEC balance was off by less than 1lb. In the next test, I
> can
>       > balance
>       >       > DEC to see if the issue still exists.
>       >       >
>       >       > My suspicion is that if DEC balance is off, then DEC might creep under gravity, even PA is perfect. So
> you
>       > might
>       >       > see DEC continually drift  then gets corrected by PHD2 periodically.
>       >       >
>       >       > Yanzhe
>       >       >
>       >       > On Sun, Mar 7, 2021 at 9:35 AM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
>       >       >
>       >       >
>       >       >       Couple of questions:
>       >       >
>       >       >
>       >       >       1 - what's the mount's serial number
>       >       >       2 - which axis is the elongation
>       >       >       3 - which direction was the scope pointing (RA-Dec)
>       >       >       4 - what scope and focal length or what is the arc sec per pixel.
>       >       >       5 - do you have a picture of your setup?
>       >       >
>       >       >
>       >       >
>       >       >       One comment about balance - it should be easy for you to completely balance the scope with the
>       > clutches
>       >       > loose. Can you estimate how many lb out of balance your scope is in Dec? Normally i would not think
> this
>       > would
>       >       > have any effect, but doesn't hurt to check this.
>       >       >
>       >       >
>       >       >
>       >       >       Roland Christen
>       >       >       Astro-Physics Inc.
>       >       >
>       >       >
>       >       >
>       >       >
>       >       >       -----Original Message-----
>       >       >       From: yanzhe liu <liuyanzhe@...>
>       >       >       To: main@ap-gto.groups.io
>       >       >       Sent: Sun, Mar 7, 2021 12:44 am
>       >       >       Subject: [ap-gto] Mach2 - Elongated stars
>       >       >
>       >       >
>       >       >       Testing new mach2 for a couple of nights. It works great out of the box and I am very pleased.
>       >       >
>       >       >       One issue bothering me is that I got slightly elongated stars across the entire image (15min Ha sub).
>       >       >       The exact same telescope/CCD were used with another mount and stars were round, I am
> wondering
>       > what I
>       >       > should check (I think there was due to some setup issue, but I could not figure it out).
>       >       >       - Used OAG for guiding, so there should not be any flexure.
>       >       >       - CCD orientation was 0/180 degree. The stars were elongated top to bottom.
>       >       >       -  I did polar alignment with PHD2 drift align. PA error should be < 5'. The field rotation of each sub
> is
>       > ~0.01
>       >       > degree, much larger than the other system (but elongated stars do not look like field rotation, they were
>       > same
>       >       > across the image)
>       >       >       - Both RA and DEC guiding curves looked smooth, had similar RMS. DEC correction was mainly to
>       > one
>       >       > direction.
>       >       >       - DEC balance was slightly off, camera heavy. Is Mach2 DEC sensitive to this? Will the
> guiding/image
>       > be
>       >       > affected?
>       >       >
>       >       >       I dont think any of the above is of particular concern, except DEC balance. Any comment/help is
>       > appreciated.
>       >       >
>       >       >       --
>       >       >       Roland Christen
>       >       >       Astro-Physics
>       >       >
>       >       >
>       >       >
>       >       >
>       >       >
>       >       >
>       >
>       >
>       >
>       >
>       >
>       >
>       >
>       >
>       >
>
>
>
>
>
>
>
>
>







--
Roland Christen
Astro-Physics