GoTos


Michael Hamburg
 

I truly love my AP900 GTO3 which I bought from the original owner a couple of years ago. However, I cannot get accurate GoTos no matter what I try. I use solely the had controller with the upgraded chip. I have synched, recalibrated, loosened  the clutches, issued GoTo commands, and retightened the clutches. I currently carry a Celestron Edge 11 HD with an Orion 80mm ED refractor piggybacked. The mount easily carries this set-up. So - is it 1) user error? 2) cone error (orthogonality?) 3) software bug? or 4) a nasty gremlin? Please help!

Michael HamburgEmoji


M Hambrick
 

Is the object database in your keypad corrupted ? You might want to cross check the coordinates that you get from the keypad with the published coordinates.

Mike


Roland Christen
 

Could be anything, depends also on how far you are off. Without more specifics, we are shooting in the wind.

Rolando

-----Original Message-----
From: Michael Hamburg via groups.io <michael_hamburg44@...>
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Wed, Oct 13, 2021 9:16 am
Subject: [ap-gto] GoTos

I truly love my AP900 GTO3 which I bought from the original owner a couple of years ago. However, I cannot get accurate GoTos no matter what I try. I use solely the had controller with the upgraded chip. I have synched, recalibrated, loosened  the clutches, issued GoTo commands, and retightened the clutches. I currently carry a Celestron Edge 11 HD with an Orion 80mm ED refractor piggybacked. The mount easily carries this set-up. So - is it 1) user error? 2) cone error (orthogonality?) 3) software bug? or 4) a nasty gremlin? Please help!

Michael HamburgEmoji

--
Roland Christen
Astro-Physics


Scott Cooke
 

Exactly. Unless you already did, it would be worth replacing the keypad battery and updating the DB of objects. 

Scott Cooke



On Oct 13, 2021, at 10:37 AM, M Hambrick <mhambrick563@...> wrote:

Is the object database in your keypad corrupted ? You might want to cross check the coordinates that you get from the keypad with the published coordinates.

Mike


Michael Hamburg
 

Thanks for the suggestions. I replaced the battery soon after I got the mount. The comparing the coordinates sounds like a good first step. How complicated is it to replace the database if necessary?
Michael


Best wishes, Michael


On Wednesday, October 13, 2021, 11:56:19 AM EDT, Scott Cooke <tscooke64@...> wrote:


Exactly. Unless you already did, it would be worth replacing the keypad battery and updating the DB of objects. 

Scott Cooke



On Oct 13, 2021, at 10:37 AM, M Hambrick <mhambrick563@...> wrote:

Is the object database in your keypad corrupted ? You might want to cross check the coordinates that you get from the keypad with the published coordinates.

Mike


Howard Hedlund
 

Keypad database corruption is generally catastrophic in terms of GoTos.  Database corruption sends you to the complete wrong place - not just *off-by-a-bit*.  And that's if you can slew to catalog objects at all.  

The number one reason by a HUGE margin for poor pointing is poor polar alignment.


Christopher Erickson
 

To me, some of the possibilities are:

1. Orthogonality/Cone-error.
2. Corrupted hand controller.
3. Misconfigured hand controller.
4. OTA/attachment mech problem.
5. Motor optical encoder problem.
6. Usage procedure problem.
7. Polar alignment problem.
8. Debris between 2 halves of mount.
9. Tripod/pier flexure/looseness.
10. Soft ground.
11. Astro-gremlins.

On Wed, Oct 13, 2021, 5:56 AM Scott Cooke <TSCOOKE64@...> wrote:
Exactly. Unless you already did, it would be worth replacing the keypad battery and updating the DB of objects. 

Scott Cooke



On Oct 13, 2021, at 10:37 AM, M Hambrick <mhambrick563@...> wrote:

Is the object database in your keypad corrupted ? You might want to cross check the coordinates that you get from the keypad with the published coordinates.

Mike


-Christopher Erickson
Observatory engineer
Waikoloa, HI 96738
www.summitkinetics.com
   


Michael Hamburg
 

PA is very good as evidenced by small corrections via PHD2.

Best wishes, Michael


On Wednesday, October 13, 2021, 12:11:20 PM EDT, Howard Hedlund <howard@...> wrote:


Keypad database corruption is generally catastrophic in terms of GoTos.  Database corruption sends you to the complete wrong place - not just *off-by-a-bit*.  And that's if you can slew to catalog objects at all.  

The number one reason by a HUGE margin for poor pointing is poor polar alignment.


Christopher Erickson
 

If the hand controller battery was replaced at some point then it is almost a certainty that the object database in the hand controller was corrupted by the bad battery, or got corrupted when the battery was replaced. Time to re-upload fresh code to the hand controller.

-Christopher Erickson
Observatory engineer
Waikoloa, HI 96738
www.summitkinetics.com
   

On Wed, Oct 13, 2021, 6:22 AM Michael Hamburg via groups.io <michael_hamburg44=yahoo.com@groups.io> wrote:
PA is very good as evidenced by small corrections via PHD2.

Best wishes, Michael


On Wednesday, October 13, 2021, 12:11:20 PM EDT, Howard Hedlund <howard@...> wrote:


Keypad database corruption is generally catastrophic in terms of GoTos.  Database corruption sends you to the complete wrong place - not just *off-by-a-bit*.  And that's if you can slew to catalog objects at all.  

The number one reason by a HUGE margin for poor pointing is poor polar alignment.


Michael Hamburg
 

Hi Christopher,
That's quite a list of culprits. Slight chance it could be #s 4 and 8. Definitely #11 is playing a big part. Pier goes down 9 feet and is filled with a lot of concrete.

Best wishes, Michael


On Wednesday, October 13, 2021, 12:22:57 PM EDT, Michael Hamburg via groups.io <michael_hamburg44@...> wrote:


PA is very good as evidenced by small corrections via PHD2.

Best wishes, Michael


On Wednesday, October 13, 2021, 12:11:20 PM EDT, Howard Hedlund <howard@...> wrote:


Keypad database corruption is generally catastrophic in terms of GoTos.  Database corruption sends you to the complete wrong place - not just *off-by-a-bit*.  And that's if you can slew to catalog objects at all.  

The number one reason by a HUGE margin for poor pointing is poor polar alignment.


Mike Dodd
 

On 10/13/2021 12:27 PM, Christopher Erickson wrote:
Time to re-upload fresh code to the hand controller.
And to answer your "how hard" question, it's easy and straightforward. Download the database file from A-P, and follow the instructions in a document named dataload201.pdf. I don't know where to find it on the website, so maybe A-P can chime in.

--- mike


Howard Hedlund
 

Scroll down this page.    https://www.astro-physics.com/software-updates/


fernandorivera3
 

You have loosened the clutches? Don't you mean "tightened down" the clutches?
Try checking your location data in the keypad. Is it accurate or way off like maybe you accidentally left it set on coordinates from a distant star party?
What about the clock time? Is it on standard time rather than daylight savings? Maybe it could be incorrect time zone setting. 

Fernando


J. Belden
 

My main problems with bad gotos with any of my AP mounts has been wrong time, wrong date.
DST Non DST as well

Joe


Christopher Erickson
 

I configure ALL my mounts to use UT.

-Christopher Erickson
Observatory engineer
Waikoloa, HI 96738
www.summitkinetics.com
   

On Wed, Oct 13, 2021, 10:47 AM J. Belden via groups.io <jjb4469=yahoo.com@groups.io> wrote:
My main problems with bad gotos with any of my AP mounts has been wrong time, wrong date.
DST Non DST as well

Joe






weems@...
 

My 900 carries a C14 and 6” f9 side by side and generally gets within 10’ of the target (closer to 7’ when not into refraction near the horizon).  And it can slew from one side of the meridian to the other then be told to return to the starting object, and will get it within 1’.  The planets are a bit off, probably because of clock drift, as I haven’t set it since the DST change.  But It wasn’t close to that until I did a draft alignment for 30 minutes in each axis, and adjusted cone error to less than 1’. It’s on a 12” concrete pier, with a very short rat cage. I replaced the flexible Celestron dovetail with a Losmandy. Every mechanical connection is also really tightened up.

Chip


fernandorivera3
 

Chip the ultimate method to get rid of flexure from your C14, beyond removing the cheap Celestron orange dovetail, is to mount the scope to a Andy Homeyer scope cradle- they are expensive but built like a tank. Absolutely rock solid.

Fernando


Michael Hamburg
 

Fernando,
Not only did I loosen the clutches, but I then retightened them. This rig never moves out my observatory!
Michael

Best wishes, Michael


On Wednesday, October 13, 2021, 03:01:33 PM EDT, fernandorivera3 via groups.io <fernandorivera3@...> wrote:


You have loosened the clutches? Don't you mean "tightened down" the clutches?
Try checking your location data in the keypad. Is it accurate or way off like maybe you accidentally left it set on coordinates from a distant star party?
What about the clock time? Is it on standard time rather than daylight savings? Maybe it could be incorrect time zone setting. 

Fernando


Michael Hamburg
 

I wish it was that simple.
Michael

Best wishes, Michael


On Wednesday, October 13, 2021, 04:47:53 PM EDT, J. Belden via groups.io <jjb4469@...> wrote:


My main problems with bad gotos with any of my AP mounts has been wrong time, wrong date.
DST Non DST as well

Joe






Scott Cooke
 

Would love to see a picture of the side by side setup.  I have thought of doing something similar with my 900.
Thanks,
Scott

On Thu, Oct 14, 2021 at 1:03 AM <weems@...> wrote:
My 900 carries a C14 and 6” f9 side by side and generally gets within 10’ of the target (closer to 7’ when not into refraction near the horizon).  And it can slew from one side of the meridian to the other then be told to return to the starting object, and will get it within 1’.  The planets are a bit off, probably because of clock drift, as I haven’t set it since the DST change.  But It wasn’t close to that until I did a draft alignment for 30 minutes in each axis, and adjusted cone error to less than 1’. It’s on a 12” concrete pier, with a very short rat cage. I replaced the flexible Celestron dovetail with a Losmandy. Every mechanical connection is also really tightened up.

Chip