Date   

Re: GTOCP4 Control Box

Christopher Erickson
 

IMNSHO, set up a compact observatory PC next to the scope and then controle that PC remotely from the house.

"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii


On Wed, Feb 24, 2021 at 12:50 PM Donald Gaines <onegaines@...> wrote:
Hi folks,
I was lucky enough to be notified recently I’m going to be the proud father of an 1100GTO mount.  I have read through the GTOCP4 Operating Instructions as I plan on how to connect the mount to a PC, CCD Camera, focuser, and other accessories.  I would like to locate the mount outside in a structure with a ROR, and connect to a PC in the house about 150  ft away. I was thinking of using the Ethernet port and I read that it can also be done with a USB and Icron 2304 USB extender.  I am curious if cameras, focuses and other accessories can be connected to the GTOCP4 and then be operated by the PC in the house?  Is there a preferred method for this kind of setup?  I would appreciate any advice you might be willing to pass along.
Thanks,
Don Gaines


GTOCP4 Control Box

Donald Gaines
 

Hi folks,
I was lucky enough to be notified recently I’m going to be the proud father of an 1100GTO mount.  I have read through the GTOCP4 Operating Instructions as I plan on how to connect the mount to a PC, CCD Camera, focuser, and other accessories.  I would like to locate the mount outside in a structure with a ROR, and connect to a PC in the house about 150  ft away. I was thinking of using the Ethernet port and I read that it can also be done with a USB and Icron 2304 USB extender.  I am curious if cameras, focuses and other accessories can be connected to the GTOCP4 and then be operated by the PC in the house?  Is there a preferred method for this kind of setup?  I would appreciate any advice you might be willing to pass along.
Thanks,
Don Gaines


Re: Encoders in the Mach2 vs 1100

Seb@stro
 

Hello Roland,

Your post made me take a quick look at Renishaw's spec for the Resolute extended temp encoder and I found two interesting observations (not related to the low temp version) which made me realize I'm probably missing something in my understanding of how the encoders actually works...

First, when we look at the following table, the "system accuracy" is increasing with the diameter of the ring (kind of opposite of what you stated earlier), which made sense to me since I would have thought that a bigger ring gives more space to mark a higher number of "ticks", hence giving higher resolution and so accuracy... So I assume the "system accuracy" of the encoder (which is defined as graduation + SDE by Renishaw) doesn't directly translate into the "tracking accuracy" of the mount.



Second observation, still looking at that table, the order of magnitude of that system accuracy seems to be more than ten-fold lower in comparison to the spec'ed tracking accuracy of the mount (+/- 3.82 arc-sec "system accuracy" for the 75 mm ring vs +/- 0.25 arc-sec "tracking accuracy" of the Mach2).

To explain these differences, my guess would be that some (gear/pulley) ratio somewhere does indeed make the tracking accuracy similar throughout the mount models and while at the same time increasing it by a factor of about 10X relative to the Renishaw's specs, but I wondered if there was more to it...

Am I lost in space ? 

Regards,
Sébastien


De : main@ap-gto.groups.io <main@ap-gto.groups.io> de la part de Roland Christen via groups.io <chris1011@...>
Envoyé : 24 février 2021 11:48
À : main@ap-gto.groups.io <main@ap-gto.groups.io>
Objet : [ap-gto] Encoders in the Mach2 vs 1100
 
Hello Astronuts,

To clear up any confusion about mount encoders, both Mach2 and 1100/1600 use the same Renishaw RESA high resolution encoders. The main difference is that the ring diameter of the 1100/1600 mounts is 100mm, the Mach2 uses a 75mm ring. Resolution and accuracy is the same for all. The readheads are the same RESA readheads, except that they are matched to their respective diameters, so that the 75mm readheads cannot be used on the 100mm rings and vice versa.

Roland Christen
Astro-Physics Inc.

--
Roland Christen
Astro-Physics


Re: Clutch Knobs vs. the Gearbox Release Levers

M Hambrick
 

To Jeffrey's comment about loading his scopes with the mount in Park 3, I used to do the same thing until I read a suggestion to load them with the mount in Park 2. This made a tremendous difference, especially with the 180 EDT. Just make sure that the counterweights are installed before loading the scope. The other advantage to loading the scopes with the mount in Park 2 is that you can install the RAPAS if you have one and polar align after everything has been installed.

Mike


Re: Clutch Knobs vs. the Gearbox Release Levers

Roland Christen
 


can I always leave my clutches tightened down and just use the release lever for fine balance.
Yes, for RA balance start out with mount in Park3. Release the lever, move the mount to horizontal, do your balance, move it back to Park3 and lock the lever.

Roland


-----Original Message-----
From: Jeffrey Wolff <jmw2800@...>
To: main@ap-gto.groups.io
Sent: Wed, Feb 24, 2021 11:02 am
Subject: Re: [ap-gto] Clutch Knobs vs. the Gearbox Release Levers

I have the 1100 on order with absolute encoders. If I only want to do fine balance and only do it from Park position 3 can I always leave my clutches tightened dow and just use the release lever for fine balance. I would never need to move the mount except under software control.

I have always loaded and unloaded my scopes when the mount is in park position 3.

--
Roland Christen
Astro-Physics


Re: Clutch Knobs vs. the Gearbox Release Levers

Jeffrey Wolff
 

I have the 1100 on order with absolute encoders. If I only want to do fine balance and only do it from Park position 3 can I always leave my clutches tightened dow and just use the release lever for fine balance. I would never need to move the mount except under software control.

I have always loaded and unloaded my scopes when the mount is in park position 3.


Encoders in the Mach2 vs 1100

Roland Christen
 

Hello Astronuts,

To clear up any confusion about mount encoders, both Mach2 and 1100/1600 use the same Renishaw RESA high resolution encoders. The main difference is that the ring diameter of the 1100/1600 mounts is 100mm, the Mach2 uses a 75mm ring. Resolution and accuracy is the same for all. The readheads are the same RESA readheads, except that they are matched to their respective diameters, so that the 75mm readheads cannot be used on the 100mm rings and vice versa.

Roland Christen
Astro-Physics Inc.

--
Roland Christen
Astro-Physics


Re: Pay Attention to Those Declination Top Plate Locking Knobs

M Hambrick
 

Thanks for the photos Jeff C.

In my younger days I used to carry my assembled 800 mount and 8-inch portable pier all at once, but no more. Everyone is talking about climate change, but what we should be talking about is gravitational constant change. What used to feel like it weighed 50 pounds when I was 38 now feels like it weighs over 100 pounds :>)

Shailesh - When I saw the photos from Jeff C they reminded me of a balancing issue that I had with my 180 EDT when I first got the mount. In Jeff's photo, the refractor in the rear with a 900 ? or 1200 ? mount on the 8-inch Astro-Physics portable pier looks very similar to what I started out with when I got my 1100 mount. You will also notice that his scope is attached to the mount on one of the A-P 18-inch Flat Plates (FP1800). I originally ordered my 1100 mount with one of these flat plates. I had to modify the plate by drilling some holes in it to match the hole pattern on my old 1992 vintage 8-inch rings, but when I was setting up everything inside the house to do the initial balancing, I could not get the scope to balance on the declination axis in the imaging mode with the camera attached. It was very heavy to the rear.

Rather than trying to drill additional holes in the flat plate, I solved the problem by purchasing one of the 16-inch dovetail saddle plates (DOVELM162) along with the 16-inch dovetail plate (SBD16). When I attached the scope to the mount using the DOVELM162 and SBD16 I was easily able to achieve balance in the declination axis by sliding the dovetail plate forward in the saddle plate.

The DOVELM162 and SBD16 have been one of the best investments I have made since purchasing the 1100 mount, and if you don't have them I highly recommend getting a set. I also purchased a couple of SBD12 dovetail plates to use with my smaller imaging scopes. The big advantage to this is that I can leave the DOVELM162 attached to the declination axis, and just attach whatever imaging scope I am using. Note that when I am setting up the 180 EDT, I first attach the SBD16 and attached rings without the 180 EDT to the dovetail saddle plate with the mount in the Park 2 position. Then, once the counterweights are attached I mount the 180 EDT into the rings. I have a set of portable stairs to facilitate this.

There is one other issue I should also mention if you have one of the A-P portable piers. I purchased my pier in 1992 for my 800 mount. It had three holes in the top for attaching the mount. The 1100 mount has 6 holes in the base. Although they told me that it was not necessary to do so, I drilled three additional holes in my pier to allow me to use all six screws. The 1100 mount base fits rather loosely into the 8-inch pier, and when the scopes, cameras, etc. as described in my earlier thread are attached to the mount, it places the center of gravity well outside (to the north) of the pier, and all that weight wants to tilt the mount towards the north. Even when the bolts attaching the mount base to the pier were tight I had several occasions where the mount tilted by about 1/16 inch after everything was attached and polar aligned using the RAPAS. To minimize the chance of this from happening I purchased some split Nord-Lock lock washers from McMaster-Carr (see below). These have been very effective at eliminating the tilting of the mount in the pier.

Mike


Re: Clutch Knobs vs. the Gearbox Release Levers

Roland Christen
 

Use the clutches when you want to manually move the scope around the sky (example: for visual sweeping of the Milky way). Use the clutches for placing the mount manually to one of the park positions during startup if you have moved the mount from a previous setup. use the clutches to get a rough balance in the two axes. The clutches can be set as tight or loose as you want with the Allen Key. There is no torque spec. except to say that you really don't need to "gorilla" the clutch knobs for them to work.

Loosen the Gearbox Release Levers only with the scope in Park3 positions. Releasing them in any other position could cause the gear teeth to rake across each other and possibly damage the worm teeth. The result will be poor guiding. Damaged teeth are expensive to fix. Use this method only for fine balance. If you don't need to do fine balance, don't release the lever.

Rolando



-----Original Message-----
From: Andrew Jones <andjones132@...>
To: main@ap-gto.groups.io
Sent: Wed, Feb 24, 2021 9:32 am
Subject: [ap-gto] Clutch Knobs vs. the Gearbox Release Levers

I have a question about when to use the Clutch Knobs vs. the Gearbox Release Levers. I currently have a Mach1 in my observatory and when balancing or moving the scope to different park positions I typically just use the Gearbox release levers rather then messing around with the clutch knobs. I have Arthritis in my hands, and getting the clutch knobs tightened without using an Allen wrench can be difficult. So I almost never use the clutches. However, I have read somewhere that I risk damaging the gears if I let the mount axis slip while releasing the Gearbox levers. I try to make sure I always have a firm hold on the scope before I release the gearbox levers, but I suppose there is always a little movement when the axis becomes free. I have never really fully understood when and why I would use the clutch knobs vs. the Gearbox release. The Gearbox release is obviously much easier and I don’t have to mess around with an Allen wrench. I am hoping some of the gurus here can provide some guidance on when to use one over the other when adjusting the position of an Axis.
 
I just put down a deposit for a 1100GTO-AEL mount and before I start using the new mount after it arrives I would like to better understand the intended purpose of Gearbox Release vs. the Clutch Knobs in order to minimize the risk of damaging the new mount. At some point I may send in my Mach1 to have it inspected just to make sure I have not damaged the gears over the years.
 
I also have a related question. How tight do the clutch knobs need to be in order for them to function properly? Given the limited strength in my hands, I tend to hand tighten them and then use and Allen wrench to give them another quarter turn. However, I have no idea if this is the “correct” way of tightening the clutches. Without needing to get out a torque wrench, is there a rule of thumb to follow when tighten the clutch knobs? Another reason I almost never used them on my Mach1 is that I didn’t want to have to worry about getting them tightened down correctly. I would think they should be loose enough so if there is ever a pier crash (hopefully never happens… again) that the mount would slip rather than keep pushing the OTA into the mount. After I tighten the clutch knobs I generally push against the OTA and see if I can get the clutches to move but still tight enough that they would not move without a fair bit of force. Once I get the clutches tightened, I then use the Gearbox release knobs to put it back in a known park position before unparking the mount.
 
Anyway, this is something that has always confused me so thought I would ask before I start using the new 1100GTO mount.
 
Thanks in advance for the useful feedback.
 
Clear Skies,
Andrew J

--
Roland Christen
Astro-Physics


Re: Pay Attention to Those Declination Top Plate Locking Knobs

Roland Christen
 

Off-axis guider is preferred method for guiding a long refractor. Next best would be to mount a Baader Guide scope using our special bracket right on the tube itself. Worst method is to mount a guide scope on top of the rings.

Rolando



-----Original Message-----
From: M Hambrick <mhambrick563@...>
To: main@ap-gto.groups.io
Sent: Tue, Feb 23, 2021 10:09 pm
Subject: Re: [ap-gto] Pay Attention to Those Declination Top Plate Locking Knobs

George & Shailesh

Good point about the holding screws. For some reason I seem to recall reading in the mount assembly instructions that they did not need to be installed if the user was planning to remove the declination top plate. Anyway, for whatever reason I never installed them. It was not long after I got the mount that I got a DOVELM162 which eliminated the need to ever remove the declination top plate. As soon as I finish this post I am going to install them.

As for the 180 EDT on the 1100 GTO mount, I have had no issues with balancing. As far as loads go, I have the scope with a pretty large and heavy SBIG STXL16200 camera and filter wheel. For guiding I use a Tele-Vue Pronto with a SBIG ST2000-XM camera piggybacked on top of the 180 EDT rings. I also have a ST-i guiding camera, but I really like the wide field of view with the ST2000. It is much easier to find guide stars. For balancing you can see my counterweight arrangement in the attached sketch. If I had a couple more 18 lb counterweights I would move more of the weight up to the top of the counterweight shaft to minimize the moment arm.

My guiding is decent enough, but I think I could do better. With an image scale of 1.1 arc-seconds per pixel, the 180 EDT really shows poor guiding. Roland has stated on many occasions that it is a bad idea to use a piggyback guide scope due to flexure. I use an A-P portable pier, and I set up and take the mount down every night, I only use the RAPAS for polar alignment, but this seems to be pretty accurate. I have not updated the PEC since I bought the mount. 

I use MaxIm DL for guiding, running separate sessions for imaging and guiding. Lately I have been working on my guiding parameters (guide exposure time, exposure delay, etc) to see if I can get better guiding, and based on Roland's comments in another post, I am going to try multi-star guiding as well. I may try to invest in one of the A-P guide scopes that mounts directly on the main OTA to eliminate the piggyback guiding, but the 250 mm focal length of the A-P guide scope seems rather short for the 180.

Mike



--
Roland Christen
Astro-Physics


Clutch Knobs vs. the Gearbox Release Levers

Andrew Jones
 

I have a question about when to use the Clutch Knobs vs. the Gearbox Release Levers. I currently have a Mach1 in my observatory and when balancing or moving the scope to different park positions I typically just use the Gearbox release levers rather then messing around with the clutch knobs. I have Arthritis in my hands, and getting the clutch knobs tightened without using an Allen wrench can be difficult. So I almost never use the clutches. However, I have read somewhere that I risk damaging the gears if I let the mount axis slip while releasing the Gearbox levers. I try to make sure I always have a firm hold on the scope before I release the gearbox levers, but I suppose there is always a little movement when the axis becomes free. I have never really fully understood when and why I would use the clutch knobs vs. the Gearbox release. The Gearbox release is obviously much easier and I don’t have to mess around with an Allen wrench. I am hoping some of the gurus here can provide some guidance on when to use one over the other when adjusting the position of an Axis.

 

I just put down a deposit for a 1100GTO-AEL mount and before I start using the new mount after it arrives I would like to better understand the intended purpose of Gearbox Release vs. the Clutch Knobs in order to minimize the risk of damaging the new mount. At some point I may send in my Mach1 to have it inspected just to make sure I have not damaged the gears over the years.

 

I also have a related question. How tight do the clutch knobs need to be in order for them to function properly? Given the limited strength in my hands, I tend to hand tighten them and then use and Allen wrench to give them another quarter turn. However, I have no idea if this is the “correct” way of tightening the clutches. Without needing to get out a torque wrench, is there a rule of thumb to follow when tighten the clutch knobs? Another reason I almost never used them on my Mach1 is that I didn’t want to have to worry about getting them tightened down correctly. I would think they should be loose enough so if there is ever a pier crash (hopefully never happens… again) that the mount would slip rather than keep pushing the OTA into the mount. After I tighten the clutch knobs I generally push against the OTA and see if I can get the clutches to move but still tight enough that they would not move without a fair bit of force. Once I get the clutches tightened, I then use the Gearbox release knobs to put it back in a known park position before unparking the mount.

 

Anyway, this is something that has always confused me so thought I would ask before I start using the new 1100GTO mount.

 

Thanks in advance for the useful feedback.

 

Clear Skies,

Andrew J


Re: Pay Attention to Those Declination Top Plate Locking Knobs

Jeffc
 

With the 1100, if one can handle the heft, the mount can be left in the "assembled" state (sans Dec plate and saddle) which reduces the setup/teardown time a bit (and simplifies the issue due to the through-mount cables).
Note the removable Dec place comes in real handy in this situation.
I also use the 1100 in a "portable" fashion... on a Losmandy HD (old style) tripod.   The Losmandy HD Tripod adapter remains on the mount for transport, and assembly just requires inserting the three large knurled bolts.    There are other details of course like installing the Control Box.    But I will warn... lifting the whole mount is a "heft".. i think it weighs about 40lbs... which to me seems about the same as the 1200 RA axis.   (I'm not sure I would recommend this tripod... it is definitely more than good enough for visual... with imaging the verdict is still out for me... I had some guiding issues but it might be operator error.)

Lick-Public-Program.jpeg


On Tue, Feb 23, 2021 at 9:44 PM Shailesh Trivedi <strivedi@...> wrote:
I use an A-P portable pier, and I set up and take the mount down every night, I only use the RAPAS for polar alignment,

Mike I am impressed that you can take the scope down every night and use RAPAS as the only polar alignment method. I have a TEC 180 currently on a Paramount MX and am contemplating using my AP1100 with AE. I too have a portable setup but with the Losmandy HD tripod.  I have tried 3x 20lb counter-weights (or could be 18lb, I forget), and one 10lb cw for balancing indoors,  to try the TEC on my AP1100 with a FLI 16803 + FW and MMOAG, My current AP1100 setup is a modest Tak FSQ106 with a Moravian G4 but I am still at the starting phase with getting it polar aligned using Pempro since I do not have visibility of Polaris even though I have the RAPAS.

Shailesh


Re: Pay Attention to Those Declination Top Plate Locking Knobs

Shailesh Trivedi
 

I use an A-P portable pier, and I set up and take the mount down every night, I only use the RAPAS for polar alignment,

Mike I am impressed that you can take the scope down every night and use RAPAS as the only polar alignment method. I have a TEC 180 currently on a Paramount MX and am contemplating using my AP1100 with AE. I too have a portable setup but with the Losmandy HD tripod.  I have tried 3x 20lb counter-weights (or could be 18lb, I forget), and one 10lb cw for balancing indoors,  to try the TEC on my AP1100 with a FLI 16803 + FW and MMOAG, My current AP1100 setup is a modest Tak FSQ106 with a Moravian G4 but I am still at the starting phase with getting it polar aligned using Pempro since I do not have visibility of Polaris even though I have the RAPAS.

Shailesh


Re: APCC pointing model effects on DEC tracking

Ray Gralak
 

Another question......what kind of problems might i see if i accidently left the pointing model
running during a camera guiding calibration and running of pempro?
That won't be a problem. You don't need to turn off tracking rate correction for autoguider calibration.

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of david w pearson via groups.io
Sent: Tuesday, February 23, 2021 7:32 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] APCC pointing model effects on DEC tracking

Thanks Ray! Another question......what kind of problems might i see if i accidently left the pointing model
running during a camera guiding calibration and running of pempro? I think i had a brain fart and forgot to
turn off.
thanks
dave


On Tuesday, February 23, 2021, 06:39:10 PM PST, Ray Gralak <iogroups@siriusimaging.com> wrote:


Hi Dave,

The initial dec tracking error is probably just dec backlash runout. Until the backlash is taken up the dec axis
wasn’t moving despite the non-zero dec tracking rate.

Regarding pointing accuracy, try opening APPM and doing a plate solve and recal with APPM. If that doesn’t
help it may be time to create a new model.

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of david w pearson via groups.io
Sent: Tuesday, February 23, 2021 2:29 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] APCC pointing model effects on DEC tracking

sorry for confusion......AP1200.
I understand that the APCC pointing model not only improved pointing but helped tracking according to Ray.
I experienced it myself after creating a pointing model.
Since i have an issue that involves APCC pointing model, maxim DL guiding, and AP1200 i need to
understand
APCC part in the process to determine how to resolve. I thought that APCC issues delta mount RA/DEC
commands according to the pointing model.
My question is does these delta RA/DEC commands require a convergence over time or not?
Meaning if the polar alignment error was vastly different from what the pointing models assumes, what
happens and how does APCC and mount behave?
thanks
dave



On Tuesday, February 23, 2021, 10:23:52 AM PST, Roland Christen via groups.io
<chris1011=aol.com@groups.io> wrote:




The DEC axis tracking error grows up to about 2-3 arc-sec tracking error

The Dec axis doesn't track. There is no tracking in Dec, only the RA axis tracks at sidereal rate. Do you mean
Dec Guiding by any chance?

APCC pointing model does not set custom tracking unless you turn on the custom rate in APPM.

Which mount are we talking about?


Rolando

-----Original Message-----
From: david w pearson via groups.io <p.davidw=yahoo.com@groups.io>
To: main@ap-gto.groups.io
Sent: Tue, Feb 23, 2021 11:43 am
Subject: [ap-gto] APCC pointing model effects on DEC tracking



Notice something new with my autoguiding, Maxim DL,APCC pointing model setup upon initial guiding during
startup. thereafter it doesn't happen.
The DEC axis tracking error grows up to about 2-3 arc-sec tracking error before converging back to normal at
0.1 to 0.3 arcsec in about 60 seconds.
During this time, i use an aggressiveness of 10 In maxim DL. Does the APCC pointing model tracking
algorithm try to compensation for DEC tracking
errors, using the pointing model, that would account for the 60 sec tracking error convergence? Also i
have
noticed that my pointing point model probably needs to be redone as
my pointing errors seem to be worse than right after model build. My first impression is my polar alignment
may be further off than the pointing model is assuming?
Any insight that would direct me toward the solution would be appreciated.
thanks
dave

--
Roland Christen
Astro-Physics







Re: Pay Attention to Those Declination Top Plate Locking Knobs

M Hambrick
 

Hi Joe

Great suggestions about using tape to mark out setting circles. I may give that a try. I used pencil to make the marks because I wanted to be able to remove them if necessary. The pencil smudges very easily however.

Mike


Re: Pay Attention to Those Declination Top Plate Locking Knobs

M Hambrick
 

George & Shailesh

Good point about the holding screws. For some reason I seem to recall reading in the mount assembly instructions that they did not need to be installed if the user was planning to remove the declination top plate. Anyway, for whatever reason I never installed them. It was not long after I got the mount that I got a DOVELM162 which eliminated the need to ever remove the declination top plate. As soon as I finish this post I am going to install them.

As for the 180 EDT on the 1100 GTO mount, I have had no issues with balancing. As far as loads go, I have the scope with a pretty large and heavy SBIG STXL16200 camera and filter wheel. For guiding I use a Tele-Vue Pronto with a SBIG ST2000-XM camera piggybacked on top of the 180 EDT rings. I also have a ST-i guiding camera, but I really like the wide field of view with the ST2000. It is much easier to find guide stars. For balancing you can see my counterweight arrangement in the attached sketch. If I had a couple more 18 lb counterweights I would move more of the weight up to the top of the counterweight shaft to minimize the moment arm.

My guiding is decent enough, but I think I could do better. With an image scale of 1.1 arc-seconds per pixel, the 180 EDT really shows poor guiding. Roland has stated on many occasions that it is a bad idea to use a piggyback guide scope due to flexure. I use an A-P portable pier, and I set up and take the mount down every night, I only use the RAPAS for polar alignment, but this seems to be pretty accurate. I have not updated the PEC since I bought the mount. 

I use MaxIm DL for guiding, running separate sessions for imaging and guiding. Lately I have been working on my guiding parameters (guide exposure time, exposure delay, etc) to see if I can get better guiding, and based on Roland's comments in another post, I am going to try multi-star guiding as well. I may try to invest in one of the A-P guide scopes that mounts directly on the main OTA to eliminate the piggyback guiding, but the 250 mm focal length of the A-P guide scope seems rather short for the 180.

Mike



Re: APCC pointing model effects on DEC tracking

david w pearson
 

Thanks Ray!  Another question......what kind of problems might i see if i accidently left the pointing model running during a camera guiding calibration and running of pempro?     I think i had a brain fart and forgot to turn off.
thanks
dave


On Tuesday, February 23, 2021, 06:39:10 PM PST, Ray Gralak <iogroups@...> wrote:


Hi Dave,

The initial dec tracking error is probably just dec backlash runout. Until the backlash is taken up the dec axis wasn’t moving despite the non-zero dec tracking rate.

Regarding pointing accuracy, try opening APPM and doing a plate solve and recal with APPM. If that doesn’t help it may be time to create a new model.

-Ray

> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of david w pearson via groups.io
> Sent: Tuesday, February 23, 2021 2:29 PM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] APCC pointing model effects on DEC tracking
>
> sorry for confusion......AP1200.
> I understand that the APCC pointing  model not only improved pointing but helped tracking according to Ray.
> I experienced it myself after creating a pointing model.
> Since i have an issue that involves APCC pointing model, maxim DL guiding, and AP1200 i need to understand
> APCC part in the process to determine how to resolve.  I thought that APCC issues delta mount RA/DEC
> commands according to the pointing model.
> My question is does these delta RA/DEC commands require a convergence over time or not?
> Meaning if the polar alignment error was vastly different from what the pointing models assumes, what
> happens and how does APCC and mount behave?
> thanks
> dave
>
>
>
> On Tuesday, February 23, 2021, 10:23:52 AM PST, Roland Christen via groups.io
> <chris1011=aol.com@groups.io> wrote:
>
>
>
>
>     The DEC axis tracking error grows up to about 2-3 arc-sec tracking error
>
> The Dec axis doesn't track. There is no tracking in Dec, only the RA axis tracks at sidereal rate. Do you mean
> Dec Guiding by any chance?
>
> APCC pointing model does not set custom tracking unless you turn on the custom rate in APPM.
>
> Which mount are we talking about?
>
>
> Rolando
>
> -----Original Message-----
> From: david w pearson via groups.io <p.davidw=yahoo.com@groups.io>
> To: main@ap-gto.groups.io
> Sent: Tue, Feb 23, 2021 11:43 am
> Subject: [ap-gto] APCC pointing model effects on DEC tracking
>
>
>
> Notice something new with my autoguiding, Maxim DL,APCC pointing model setup upon initial guiding during
> startup.  thereafter it doesn't happen.
> The DEC axis tracking error grows up to about 2-3 arc-sec tracking error before converging back to normal at
> 0.1 to 0.3 arcsec in about 60 seconds.
> During this time, i use an aggressiveness of 10 In maxim DL.      Does the APCC pointing model tracking
> algorithm try to compensation for DEC tracking
> errors, using the pointing model, that would account for the 60 sec tracking error convergence?      Also i have
> noticed that my pointing point model probably needs to be redone as
>  my pointing errors seem to be worse than right after model build.    My first impression is my polar alignment
> may be further off than the pointing model is assuming?
> Any insight that would direct me toward the solution would be appreciated.
> thanks
> dave
>
> --
> Roland Christen
> Astro-Physics
>







Re: APCC pointing model effects on DEC tracking

Ray Gralak
 

Hi Dave,

The initial dec tracking error is probably just dec backlash runout. Until the backlash is taken up the dec axis wasn’t moving despite the non-zero dec tracking rate.

Regarding pointing accuracy, try opening APPM and doing a plate solve and recal with APPM. If that doesn’t help it may be time to create a new model.

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of david w pearson via groups.io
Sent: Tuesday, February 23, 2021 2:29 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] APCC pointing model effects on DEC tracking

sorry for confusion......AP1200.
I understand that the APCC pointing model not only improved pointing but helped tracking according to Ray.
I experienced it myself after creating a pointing model.
Since i have an issue that involves APCC pointing model, maxim DL guiding, and AP1200 i need to understand
APCC part in the process to determine how to resolve. I thought that APCC issues delta mount RA/DEC
commands according to the pointing model.
My question is does these delta RA/DEC commands require a convergence over time or not?
Meaning if the polar alignment error was vastly different from what the pointing models assumes, what
happens and how does APCC and mount behave?
thanks
dave



On Tuesday, February 23, 2021, 10:23:52 AM PST, Roland Christen via groups.io
<chris1011=aol.com@groups.io> wrote:




The DEC axis tracking error grows up to about 2-3 arc-sec tracking error

The Dec axis doesn't track. There is no tracking in Dec, only the RA axis tracks at sidereal rate. Do you mean
Dec Guiding by any chance?

APCC pointing model does not set custom tracking unless you turn on the custom rate in APPM.

Which mount are we talking about?


Rolando

-----Original Message-----
From: david w pearson via groups.io <p.davidw=yahoo.com@groups.io>
To: main@ap-gto.groups.io
Sent: Tue, Feb 23, 2021 11:43 am
Subject: [ap-gto] APCC pointing model effects on DEC tracking



Notice something new with my autoguiding, Maxim DL,APCC pointing model setup upon initial guiding during
startup. thereafter it doesn't happen.
The DEC axis tracking error grows up to about 2-3 arc-sec tracking error before converging back to normal at
0.1 to 0.3 arcsec in about 60 seconds.
During this time, i use an aggressiveness of 10 In maxim DL. Does the APCC pointing model tracking
algorithm try to compensation for DEC tracking
errors, using the pointing model, that would account for the 60 sec tracking error convergence? Also i have
noticed that my pointing point model probably needs to be redone as
my pointing errors seem to be worse than right after model build. My first impression is my polar alignment
may be further off than the pointing model is assuming?
Any insight that would direct me toward the solution would be appreciated.
thanks
dave

--
Roland Christen
Astro-Physics


Re: APCC pointing model effects on DEC tracking

david w pearson
 

sorry for confusion......AP1200.
I understand that the APCC pointing  model not only improved pointing but helped tracking according to Ray.
I experienced it myself after creating a pointing model.
Since i have an issue that involves APCC pointing model, maxim DL guiding, and AP1200 i need to understand APCC part in the process to determine how to resolve.  I thought that APCC issues delta mount RA/DEC commands according to the pointing model.
My question is does these delta RA/DEC commands require a convergence over time or not?
Meaning if the polar alignment error was vastly different from what the pointing models assumes, what happens and how does APCC and mount behave?
thanks
dave



On Tuesday, February 23, 2021, 10:23:52 AM PST, Roland Christen via groups.io <chris1011@...> wrote:



The DEC axis tracking error grows up to about 2-3 arc-sec tracking error
The Dec axis doesn't track. There is no tracking in Dec, only the RA axis tracks at sidereal rate. Do you mean Dec Guiding by any chance?
APCC pointing model does not set custom tracking unless you turn on the custom rate in APPM.
Which mount are we talking about?

Rolando

-----Original Message-----
From: david w pearson via groups.io <p.davidw@...>
To: main@ap-gto.groups.io
Sent: Tue, Feb 23, 2021 11:43 am
Subject: [ap-gto] APCC pointing model effects on DEC tracking

 
Notice something new with my autoguiding, Maxim DL,APCC pointing model setup upon initial guiding during startup.   thereafter it doesn't happen.
The DEC axis tracking error grows up to about 2-3 arc-sec tracking error before converging back to normal at 0.1 to 0.3 arcsec in about 60 seconds.
During this time, i use an aggressiveness of 10 In maxim DL.      Does the APCC pointing model tracking algorithm try to compensation for DEC tracking 
errors, using the pointing model, that would account for the 60 sec tracking error convergence?      Also i have noticed that my pointing point model probably needs to be redone as
 my pointing errors seem to be worse than right after model build.     My first impression is my polar alignment may be further off than the pointing model is assuming?
Any insight that would direct me toward the solution would be appreciated.
thanks
dave

--
Roland Christen
Astro-Physics


Re: Sticky 600E Controller Button

George
 

John,

 

If you want to send it to us, we can replace the buttons for you.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-222-6538 (direct line)

Phone:  815-282-1513 (office)

Email:  george@...

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Elenillor
Sent: Tuesday, February 23, 2021 3:24 PM
To: main@ap-gto.groups.io
Subject: [ap-gto] Sticky 600E Controller Button

 

Not a goto mount but my mid 90's 600E stepper motor hand controller has an intermittently sticky north button. Any suggestions on how to fix it? 

Taking the cover off the controller it seems straightfoward to unsolder and replace a button. Any suggestion of a decent replacement button?

I removed the covers on the N and W buttons so it was easy to feel the difference in the dark.

John

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