Mach 1 not parking at Alt Az position


Arun Hegde
 

Hello,

I have a Mach 1 that is running off of CP3. I've programmed the Alt Az position to be with the counterweight bar horizontal and scope pointed straight up for flats. Recently, it doesn't quite park in that position; it moves very close to that position and indicates it is still slewing with very minute movements shown until I abort the park. Wondering if this is indicative of some kind of issue or there is way of fixing it? I have tried changing the alt az position slightly, but it won't park there either. It has no issues parking to Park 3.

Arun


 

What is your setup? Are you using APCC and other programs, the keypad, or something else to send the command? 


Liam




From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Arun Hegde <arun.k.hegde@...>
Sent: Wednesday, February 3, 2021 9:40 AM
To: main@ap-gto.groups.io
Subject: [ap-gto] Mach 1 not parking at Alt Az position
 
Hello,

I have a Mach 1 that is running off of CP3. I've programmed the Alt Az position to be with the counterweight bar horizontal and scope pointed straight up for flats. Recently, it doesn't quite park in that position; it moves very close to that position and indicates it is still slewing with very minute movements shown until I abort the park. Wondering if this is indicative of some kind of issue or there is way of fixing it? I have tried changing the alt az position slightly, but it won't park there either. It has no issues parking to Park 3.

Arun


Howard Hedlund
 

Hello Arun,

Are you using the AP V2 ASCOM driver, or APCC or something else?   Do you know what firmware version is in your GTOCP3?   Both APCC and the driver will tell you the version.


Arun Hegde
 

Thanks for the responses. I am using the AP V2 ASCOM driver. I can get the GTO CP3 firmware version later in the evening. I have a keypad but have never used it since the mount is exclusively used for imaging.


Arun Hegde
 
Edited

Bumping this in the hope that someone has some experience here:

issue/Problem statement: Mount will not indicate is is parked at Alt Az position although it gets very, very very close. The AP V2 ASCOM driver which I use seems to show minute movements even when pretty much at position, and I end up manually aborting the park,

Software/Firmware: AP v2 ASCOM driver, Firmware rev Q; GTO CP3, no V2 chip.


Ray Gralak
 

Arun,

Alt/Az position may appear to change slightly because it gets calculated from these polled values from the mount: RA, Dec, and Local Sidereal Time.

Although Dec is constant when parked, RA and Local Sidereal Time change so that makes the Alt/Az position appear to move around.

As to why the mount doesn't seem to park, we would have to see your log(s).

Specifically:

1) Connect to your mount.
2) Slew the mount somewhere away from the park position
3) Park the mount.
4) Wait at least 10 minutes after the park, then disconnect from the mount.
5) Use the AP driver's Log Zipper utility to zip your logs and settings files.
6) Email the zip file to me at groups3 @ gralak dot com.

-Ray Gralak
Author of PEMPro
Author of APCC (Astro-Physics Command Center): https://www.astro-physics.com/apcc-pro
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Arun Hegde
Sent: Friday, February 5, 2021 7:09 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Mach 1 not parking at Alt Az position

[Edited Message Follows]
[Reason: added GTO CP3 details]

Bumping this in the hope that someone has some experience here:

issue/Problem statement: Mount will not indicate is is parked at Alt Az position although it gets very, very very
close. The AP V2 ASCOM driver which I use seems to show minute movements even when pretty much at
position, and I end up manually aborting the park,

Software/Firmware: AP v2 ASCOM driver, Firmware rev Q; GTO CP3, no V2 chip.


Mike Dodd
 

On 2/5/2021 10:08 AM, Arun Hegde wrote:

issue/Problem statement: Mount will not indicate is is parked at Alt Az
position although it gets very, very very close. The AP V2 ASCOM driver
which I use seems to show minute movements even when pretty much at
position, and I end up manually aborting the park.
Questions:

1. Does the driver say Parked or Unparked when you see these tiny movements?

2. If you manually slew the mount using the driver's buttons, then park it using the driver's Park (to Az/El) button, does the driver park the scope? I.e., do the coordinate fields blink "Parking Click to Cancel" then stop when the mount stops moving?

3. If #2 is "yes" then the mount is parked. Do you still see the tiny movements?

I don't think this is really a problem. As I understand it, the driver is converting RA/Dec to Alt/El, and you're probably seeing tiny rounding errors. If the driver says Parked, then the mount is parked.

--- Mike


michaeljhanson@...
 

Arun,

Check for imbalance.  Rev Q is very old and does not have integral gain to overcome a tiny positional error due to heavy imbalance.  Park 3 might work because the weight is symmetric.

Regards,
Mike Hanson


Arun Hegde
 
Edited

Thank you Mike and Ray.

Ray - I will email the requested files to you.

Mike - In answer to your question "Parking - click to cancel" never stops even though the mount has apparently reached the Alt Az position from what I can visually see. The good thing is that once it reaches that position, it never strays very far from it, just indicates it is still in the process of parking. So I simply click to cancel and get on with taking flats.

Mike H - Thanks for the advice on balance. The mount has been very forgiving to balance so I've never bothered to critically balance it, but will try that. The nice thing is that all these things can be done in cloudy weather!


Arun Hegde
 

I wanted to circle back and document how this ended in case anyone has the same issue.

I set the mount and scope up, verified balance and verified that it would park at positions 1-4. Once this was done, I tried to get it to park at Alt Az, and had the same issue as before. Then I aborted the park, manually went to what I wanted Alt Az to be, commanded it to park at current position. Once parked, I set Alt Az. Now it repeatably parks at Alt Az. 

I can only assume that the last time I set Alt Az, the mount was not actually parked at that position where it needed to be.


Roland Christen
 

Thank you for posting your update.

Rolando



-----Original Message-----
From: Arun Hegde <arun.k.hegde@...>
To: main@ap-gto.groups.io
Sent: Sat, Feb 6, 2021 5:24 pm
Subject: Re: [ap-gto] Mach 1 not parking at Alt Az position

I wanted to circle back and document how this ended in case anyone has the same issue.

I set the mount and scope up, verified balance and verified that it would park at positions 1-4. Once this was done, I tried to get it to park at Alt Az, and had the same issue as before. Then I aborted the park, manually went to what I wanted Alt Az to be, commanded it to park at current position. Once parked, I set Alt Az. Now it repeatably parks at Alt Az. 

I can only assume that the last time I set Alt Az, the mount was not actually parked at that position where it needed to be.

--
Roland Christen
Astro-Physics