Date   

Re: How to Re-grease a Mach1 with Auto-Adjust Motor Boxes?

Cheng-Yang Tan
 

Definitely a video!

cytan

On Monday, March 8, 2021, 09:30:21 AM CST, Andrew Jones <andjones132@...> wrote:


Hi Bill.

Thank you for sharing your experience. I know you to be a very knowledgeable amateur astronomer based on your many useful and helpful post on the forum. If someone with your level expertise struggled with this re-greasing process the first time, to point of actually damaging the mount, does not give me warm and fuzzys about attempting the process myself. Given the recommendation that all owners of AP mounts should be performing this maintenance ever 2 - 5 years would indicate a strong demand for clear and concise instructions for each mount. I am sure we could all call George and have him walk us through the process step by step, but it would seem easier (for AP) if we could just get a step-by-step guide or even better a YouTube Video showing each step in detail. I am going to hold off with re-greasing my Mach1 from 2016 for now until hopefully some better instructions come along. 

Thanks again for sharing your experience. 

Andrew J


Re: How to Re-grease a Mach1 with Auto-Adjust Motor Boxes?

Andrew J
 

Hi Bill.

Thank you for sharing your experience. I know you to be a very knowledgeable amateur astronomer based on your many useful and helpful post on the forum. If someone with your level expertise struggled with this re-greasing process the first time, to point of actually damaging the mount, does not give me warm and fuzzys about attempting the process myself. Given the recommendation that all owners of AP mounts should be performing this maintenance ever 2 - 5 years would indicate a strong demand for clear and concise instructions for each mount. I am sure we could all call George and have him walk us through the process step by step, but it would seem easier (for AP) if we could just get a step-by-step guide or even better a YouTube Video showing each step in detail. I am going to hold off with re-greasing my Mach1 from 2016 for now until hopefully some better instructions come along. 

Thanks again for sharing your experience. 

Andrew J


Re: New Mach2 #Mach2GTO

fernandorivera3
 

Bill, you're under cloud cover since November & no clear skies anytime soon? Are you in Seattle or other part of the Pacific NW??

Fernando


Re: Leave RAPAS installed or not?

M Hambrick
 

It is so easy to install and remove the RAPAS (3 screws) that I think the prudent thing to do would be to remove it after you have polar aligned.

Mike


Re: How to Re-grease a Mach1 with Auto-Adjust Motor Boxes?

thefamily90 Phillips
 

Roger that!

JimP


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of fernandorivera3 via groups.io <fernandorivera3@...>
Sent: Monday, March 8, 2021 1:32:18 AM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] How to Re-grease a Mach1 with Auto-Adjust Motor Boxes?
 
Maybe someday there will be step by step videos that are in depth, explaining & showing the process of each of the mounts being re-greased, on YouTube. So we can click to view whichever mount applies to us: Mach 1, Mach 2, 900, 1100, 1200, or 1600 GTO's. 

Fernando


Re: Quick Release Gearbox Modification for Older AP1600

thefamily90 Phillips
 

My AP mounts do tend to offer some resistance when balancing but after about 30 years using AP mounts I have gotten used to it.

JimP


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Jack Huerkamp <Mallincamusa@...>
Sent: Monday, March 8, 2021 8:14:25 AM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: [ap-gto] Quick Release Gearbox Modification for Older AP1600
 
I have an older AP1600 mount that does not have the quick release option for the RA and Dec gears.  Is Astro-Physics going to release an upgrade kit for older mounts to allow for quick un-meshing of the gears?  I have a friend who has the new version of the mount, and he can easily un-mesh the gears and precisely balance the mount.  In my case, even with the clutches fully loosened, there remains so much resistance to movement, that achieving a precise balance is impossible.  I use an electronic fish scale to try to achieve balance, but it takes over 10# of force to get the mount to move in either direction with the clutch screws loosened.  Is this normal?

Jack Huerkamp


Quick Release Gearbox Modification for Older AP1600

Jack Huerkamp
 

I have an older AP1600 mount that does not have the quick release option for the RA and Dec gears.  Is Astro-Physics going to release an upgrade kit for older mounts to allow for quick un-meshing of the gears?  I have a friend who has the new version of the mount, and he can easily un-mesh the gears and precisely balance the mount.  In my case, even with the clutches fully loosened, there remains so much resistance to movement, that achieving a precise balance is impossible.  I use an electronic fish scale to try to achieve balance, but it takes over 10# of force to get the mount to move in either direction with the clutch screws loosened.  Is this normal?

Jack Huerkamp


Re: How to Re-grease a Mach1 with Auto-Adjust Motor Boxes?

fernandorivera3
 

Maybe someday there will be step by step videos that are in depth, explaining & showing the process of each of the mounts being re-greased, on YouTube. So we can click to view whichever mount applies to us: Mach 1, Mach 2, 900, 1100, 1200, or 1600 GTO's. 

Fernando


Re: Mach2 - Elongated stars

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
>
>
>
>
>
>









Re: Problem with first startup of Mach2 -- obstruction / grinding sound

Don Anderson
 

You won’t regret a decision to get a AP mount or any other product made by Astro Physics. The support is tremendous not just from Rolland but from everyone at AP. 
Welcome to the family😋




On Saturday, March 6, 2021, 3:56 PM, Bill Long <bill@...> wrote:

Welcome to the group! I completely agree that AP's customer service is the best of the bunch! 


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of odessouky@... <odessouky@...>
Sent: Saturday, March 6, 2021 2:12 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Problem with first startup of Mach2 -- obstruction / grinding sound
 
I have just joined this group, as I am researching buying my first PREMIUM mount.

Considering it will be a big expenditure for me, I wanted to make a good and informed decision.

Seeing Roland's response here on this thread, and his engagement with his customers who have already parted with their hard earned money is very inspiring and commands respect. I am pleasantly surprised at te level of engagement and support!

:)

I have been researching buying either an AP vs another premium European brand mount.

I had requested to join the European brand's forums to see user's and owner's experiences in the field, and the level of support they are receiving. I have not been impressed.

Just reading through this thread has completely sold me on AP. I'm glad I followed the advice on Cloudy Nights to join this group!

Too bad that I live in the UK! 


Re: Mach2 - Elongated stars

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
>
>
>
>
>
>







Re: Mach2 - Elongated stars

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


Re: Stellarmate with Astro-Physics mount

Bill Long
 

The new Keypad Version coming out will let you use the keypad to build a model.


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Arvind <base16@...>
Sent: Sunday, March 7, 2021 2:40 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: [ap-gto] Stellarmate with Astro-Physics mount
 
I’m looking to see if anyone has built a pointing model with a CP4 by a sequence of GoTo, platesolve, sync (refine) through Stellarmate. 

It's great that we have APCC Pro (which I'll receive with the 1100) but I'm looking for alternatives that can do the above as a blackbox and be usable through iPhone/iPad. 

Thanks. 


Stellarmate with Astro-Physics mount

Arvind
 

I’m looking to see if anyone has built a pointing model with a CP4 by a sequence of GoTo, platesolve, sync (refine) through Stellarmate. 

It's great that we have APCC Pro (which I'll receive with the 1100) but I'm looking for alternatives that can do the above as a blackbox and be usable through iPhone/iPad. 

Thanks. 


Re: Mach2 - Elongated stars

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






Re: Mach2 - Elongated stars

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


Re: Mach2 - Elongated stars

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


Mistake on a previous post

Roland Christen
 

In a previous post discussing encoders for our various mounts I posted this:

"The main difference is that the ring diameter of the 1100/1600 mounts is 100mm, the Mach2 uses a 75mm ring."

It should read the Mach2 uses 57mm not 75mm rings. (5 and 7 were swapped - dyslectic or ?) Sorry for the confusion.

In the Mach2 the special ring carriers were machined into the housing, and the wiring is simpler and does not require the extra crossover boxes that the 1100 mount needs to adapt the encoder rings. Making the Mach2 mount encoder-only allowed significant savings. It eliminated the expensive DC servo motor-encoder that is required on our Mach1 and 1100/1600 mounts.

Rolando

--
Roland Christen
Astro-Physics


Re: Mach2 - Elongated stars

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.
>







Re: Mach2 - Elongated stars

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

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