Date   

Re: DEC Crosstalk

Clayton Yendrey
 

Brian,
I do understand that, but although I leave the mount on the pier in the backyard, I do not leave the OTA there.  For safe carrying, I have a D plate handle assembly; to use it I remove the guide camera/scope from the top D plate and install the handle to carry the OTA safely/securely.  Since I am 'disturbing' the guide scope assembly each time I mount/dismount the OTA, I perform a calibration.  On the few times I've actually had back to back viewing nights, I have left the OTA on the mount and have not recalibrated.


Re: DEC Crosstalk

Clayton Yendrey
 

Roland,
Thanks for the excellent explanation of what happens.  That would explain, I believe, the appearance of large RA spikes literally out of nowhere.  It would seem that the bearing mount/assembly, besides lacking preload, could also be insufficiently rigid as a contributing factor?

This problem is more prevalent/larger magnitude when the mount pointing at high declinations.  It was around 3 hrs before meridian flip on the target (M51).  No spikes readily apparent when guiding at Dec 0/10 minutes west of meridian but began occurring immediately after slewing to target (M51).


Re: DEC Crosstalk

 

>>> other than indicating that I don't always have the axis of the guide camera aligned with the axis of the mount movement.  I typically try to adjust/make it perpendicular on the next calibration.  In this instance it was about (going by memory) about 3dg tilt.

two things

first you do not need to do this. that is the purpose of the calibration

second, if you adjust it after calibration, that invalidates the calibration

All you need to do is calibrate and leave it alone



On Wed, May 12, 2021 at 2:33 PM Clayton Yendrey <cyendrey@...> wrote:

Ortho looked good, always has with this mount - other than indicating that I don't always have the axis of the guide camera aligned with the axis of the mount movement.  I typically try to adjust/make it perpendicular on the next calibration.  In this instance it was about (going by memory) about 3dg tilt.

To be clear, this is NOT an AP mount that I'm working with at the moment.  A comment was made about this being a general issue with GEM mounts by the Support for that mount.  Since I don't see/haven't found many/any discussions about DEC causing spike (crosstalk) in the RA across several different internet searches, I thought I'd ask the other manufacturers support directly.  Of course, doesn't hurt that I only have 22 months to go on my Mach2 waiting list...   



--
Brian 



Brian Valente


Re: DEC Crosstalk

Clayton Yendrey
 

Ortho looked good, always has with this mount - other than indicating that I don't always have the axis of the guide camera aligned with the axis of the mount movement.  I typically try to adjust/make it perpendicular on the next calibration.  In this instance it was about (going by memory) about 3dg tilt.

To be clear, this is NOT an AP mount that I'm working with at the moment.  A comment was made about this being a general issue with GEM mounts by the Support for that mount.  Since I don't see/haven't found many/any discussions about DEC causing spike (crosstalk) in the RA across several different internet searches, I thought I'd ask the other manufacturers support directly.  Of course, doesn't hurt that I only have 22 months to go on my Mach2 waiting list...   


Re: Dual scope setup question

Worsel
 

Yanzhe

There was a short thread on the dual scope topic back in March.  In fact, it was specific to the 1100, so you may find useful info at
https://ap-gto.groups.io/g/main/topic/81188350#76876

Bryan


Re: Dual scope setup question

Bruce Donzanti
 

I have an 80mm piggybacked on top of my C11" on my AP1100.  Cameras on both with filter wheels and auto-focusers 7 USB ports.  I use to guide the 80mm with the OAG on the C11 and that works most of the time.  However, during windy nights it could struggle so I placed a second OAG on the 80mm and it works fine all of the time.  


Re: Dual scope setup question

Kent Kirkley
 

By 'one at a time", are you referring to imaging?
Either way can work, I've done both.
The biggest issue will be the possibility of flexure between
components depending on how you will be guiding.
If you intend to use an off axis guider on both scopes, no problem.
If you intend to use a guide scope of some sort, be wary of how it's
mounted. Scopes are usually mounted in rings which have felt, cork or
some other material lining them. If a guide scope is mounted on the rings,
the main scope can move slightly within the rings which the guider won't
know about. The result, oval or trailed stars.

To prevent this, mount the guide scope directly on the primary instrument, not
on the rings.
This also applies to a side by side set up where you mount the guide scope
on the side by side plate.

Kent Kirkley




-----Original Message-----
From: yanzhe liu <liuyanzhe@...>
To: main@ap-gto.groups.io
Sent: Wed, May 12, 2021 3:53 pm
Subject: [ap-gto] Dual scope setup question

Have been thinking of setting up two scopes (4" and 5") on AP1100, only 1 scope will be used at any time.
A few questions on exactly how it should be configured/connected.
- Piggy back vs side by side? Which is the preferred way.
- I am thinking of having 3 110v/12V power adapters, and 3 USB ports.
One power adapter and one USB port are for connecting GTOCP3.
Each telescope will have a power adapter and a USB port, which provide power and communication for all gears eg, CCD/focuser/dew controller/USB hub etc.

I am not too sure whether there are any potential issues with this setup:
- Can all 4 cables (2 powers and 2 USB2 cables) go through AP1100?
- Is there any concern on the electrical side, e.g. USB ground loop or something similar?
- Or is it possible to have 2 scopes sharing the same power and USB? Then I need a IP controller 12v power switch?

Yanzhe



Dual scope setup question

yanzhe liu
 

Have been thinking of setting up two scopes (4" and 5") on AP1100, only 1 scope will be used at any time.
A few questions on exactly how it should be configured/connected.
- Piggy back vs side by side? Which is the preferred way.
- I am thinking of having 3 110v/12V power adapters, and 3 USB ports.
One power adapter and one USB port are for connecting GTOCP3.
Each telescope will have a power adapter and a USB port, which provide power and communication for all gears eg, CCD/focuser/dew controller/USB hub etc.

I am not too sure whether there are any potential issues with this setup:
- Can all 4 cables (2 powers and 2 USB2 cables) go through AP1100?
- Is there any concern on the electrical side, e.g. USB ground loop or something similar?
- Or is it possible to have 2 scopes sharing the same power and USB? Then I need a IP controller 12v power switch?

Yanzhe



Re: APCC pro refraction modeling for nomad setup #Mach2GTO #APCC

Andrea Lucchetti
 

thank you everyone.
I need to be quicker in setting up the rig: my last night out was in November and this doesn't allow me to build a routine...
in the future I'd like to run a small model before imaging, but for now I like the trick suggested by Ray.
I am curious to see how long unguided I can go, with a mach 2 polar aligned on the refracted pole and refraction keyed in.
andrea


Re: DEC Crosstalk

Roland Christen
 

Typically, crosstalk occurs when the Dec axis is moved slightly during guiding, and this causes a corresponding Ra movement. It typically happens when the scope is pointed toward the meridian (sometimes from zenith to the pole). The wiping action of the Dec worm against the Dec worm wheel causes the wheel to lift slightly if the Dec bearings are not highly pre-loaded. The entire worm wheel and shaft will tilt slightly back and forth as the worm gear turns in the worm wheel teeth. It's caused by friction of the worm teeth against the worm gear. This slight tilting is in the direction of RA but cannot be seen as an RA shaft motion.

Rolando

-----Original Message-----
From: Brian Valente <bvalente@...>
To: main@ap-gto.groups.io
Sent: Wed, May 12, 2021 3:05 pm
Subject: Re: [ap-gto] DEC Crosstalk

Hi Clayton
>>>I'm trying to get some idea/context for the issue of DEC crosstalk to the RA axis during tracking/guiding.

How does the orthagonality of your guiding calibration look? if it's not at 90 degrees, that would cause mirroring between the axis



On Wed, May 12, 2021 at 12:59 PM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
I have never seen it in any of our present mounts. It can happen if the Dec main bearings are not fully pre-loaded.

Rolando


-----Original Message-----
From: Clayton Yendrey <cyendrey@...>
To: main@ap-gto.groups.io
Sent: Wed, May 12, 2021 2:46 pm
Subject: [ap-gto] DEC Crosstalk

I'm trying to get some idea/context for the issue of DEC crosstalk to the RA axis during tracking/guiding.  I see this as a topic that seems to come with different users in the Paramount forums almost continuously - in other words while user may/may not get it resolved with adjustments to worm engagement, there is usually someone else that will have a similar issue shortly, so there is never an true absence of problems being reported.  I did not see this reported as an stand alone issue when I had an EQ6R, nor when I had an Ioptron GEM45 in those respective user groups.
I'm not saying it doesn't occur, but I can't remember a specific case of someone reporting this particular issue in the AP-GTO groups.  I've seen it stated on a few occasions in the Paramount forums that all GEM mounts are subject to this problem (with the sub text that there isn't a problem with the Paramount's design).  I'm not asking about the Paramounts (although I have one while waiting for my turn at a Mach2).  
What I'm trying to gauge the accuracy of is the generalization from them that this is just something that GEM mounts have and users just need to deal with it.  Seems if that was the case, it would tend to be more visible in other forums?  So is this something that is inherent to GEM mounts / AP mounts and how prevalent is it/how is it dealt with?
 
Thanks in advance,
Clayton

--
Roland Christen
Astro-Physics


--
Brian 



Brian Valente

--
Roland Christen
Astro-Physics


Re: DEC Crosstalk

 

Hi Clayton
>>>I'm trying to get some idea/context for the issue of DEC crosstalk to the RA axis during tracking/guiding.

How does the orthagonality of your guiding calibration look? if it's not at 90 degrees, that would cause mirroring between the axis



On Wed, May 12, 2021 at 12:59 PM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
I have never seen it in any of our present mounts. It can happen if the Dec main bearings are not fully pre-loaded.

Rolando


-----Original Message-----
From: Clayton Yendrey <cyendrey@...>
To: main@ap-gto.groups.io
Sent: Wed, May 12, 2021 2:46 pm
Subject: [ap-gto] DEC Crosstalk

I'm trying to get some idea/context for the issue of DEC crosstalk to the RA axis during tracking/guiding.  I see this as a topic that seems to come with different users in the Paramount forums almost continuously - in other words while user may/may not get it resolved with adjustments to worm engagement, there is usually someone else that will have a similar issue shortly, so there is never an true absence of problems being reported.  I did not see this reported as an stand alone issue when I had an EQ6R, nor when I had an Ioptron GEM45 in those respective user groups.
I'm not saying it doesn't occur, but I can't remember a specific case of someone reporting this particular issue in the AP-GTO groups.  I've seen it stated on a few occasions in the Paramount forums that all GEM mounts are subject to this problem (with the sub text that there isn't a problem with the Paramount's design).  I'm not asking about the Paramounts (although I have one while waiting for my turn at a Mach2).  
What I'm trying to gauge the accuracy of is the generalization from them that this is just something that GEM mounts have and users just need to deal with it.  Seems if that was the case, it would tend to be more visible in other forums?  So is this something that is inherent to GEM mounts / AP mounts and how prevalent is it/how is it dealt with?
 
Thanks in advance,
Clayton

--
Roland Christen
Astro-Physics



--
Brian 



Brian Valente


Re: DEC Crosstalk

Roland Christen
 

I have never seen it in any of our present mounts. It can happen if the Dec main bearings are not fully pre-loaded.

Rolando


-----Original Message-----
From: Clayton Yendrey <cyendrey@...>
To: main@ap-gto.groups.io
Sent: Wed, May 12, 2021 2:46 pm
Subject: [ap-gto] DEC Crosstalk

I'm trying to get some idea/context for the issue of DEC crosstalk to the RA axis during tracking/guiding.  I see this as a topic that seems to come with different users in the Paramount forums almost continuously - in other words while user may/may not get it resolved with adjustments to worm engagement, there is usually someone else that will have a similar issue shortly, so there is never an true absence of problems being reported.  I did not see this reported as an stand alone issue when I had an EQ6R, nor when I had an Ioptron GEM45 in those respective user groups.
I'm not saying it doesn't occur, but I can't remember a specific case of someone reporting this particular issue in the AP-GTO groups.  I've seen it stated on a few occasions in the Paramount forums that all GEM mounts are subject to this problem (with the sub text that there isn't a problem with the Paramount's design).  I'm not asking about the Paramounts (although I have one while waiting for my turn at a Mach2).  
What I'm trying to gauge the accuracy of is the generalization from them that this is just something that GEM mounts have and users just need to deal with it.  Seems if that was the case, it would tend to be more visible in other forums?  So is this something that is inherent to GEM mounts / AP mounts and how prevalent is it/how is it dealt with?
 
Thanks in advance,
Clayton

--
Roland Christen
Astro-Physics


DEC Crosstalk

Clayton Yendrey
 

I'm trying to get some idea/context for the issue of DEC crosstalk to the RA axis during tracking/guiding.  I see this as a topic that seems to come with different users in the Paramount forums almost continuously - in other words while user may/may not get it resolved with adjustments to worm engagement, there is usually someone else that will have a similar issue shortly, so there is never an true absence of problems being reported.  I did not see this reported as an stand alone issue when I had an EQ6R, nor when I had an Ioptron GEM45 in those respective user groups.

I'm not saying it doesn't occur, but I can't remember a specific case of someone reporting this particular issue in the AP-GTO groups.  I've seen it stated on a few occasions in the Paramount forums that all GEM mounts are subject to this problem (with the sub text that there isn't a problem with the Paramount's design).  I'm not asking about the Paramounts (although I have one while waiting for my turn at a Mach2).  

What I'm trying to gauge the accuracy of is the generalization from them that this is just something that GEM mounts have and users just need to deal with it.  Seems if that was the case, it would tend to be more visible in other forums?  So is this something that is inherent to GEM mounts / AP mounts and how prevalent is it/how is it dealt with?

 

Thanks in advance,
Clayton


Re: Counterweight Shaft Travel Storage

rtlangland
 

Hi John,

I also have an AP 1100. I have two shafts because with a smaller scope I have to use the shorter shaft. Either way I purchased a zippered carrying case designed for a tripod . I don’t remember where I purchased it. However, it has some ties sewn into the back of the case to hold the shaft from moving around too much. They have a slight rubberized coating that kind of holds onto the shaft  It also has carrying straps and even a shoulder strap and this setup works fine for me. The one I bought also has a smaller zippered pouch on the  inside where I store the plastic cap on the shaft after the shaft is installed on the mount. It keeps it convenient so I don’t misplace it.

Hope this helps.

Bob Langland

On May 12, 2021, at 9:40 AM, Fritz K <fritztwo@...> wrote:

I have the 1100 shaft with extension.  I used to carry it in my counter weight box, but now that is too heavy for this old guy.
So I keep the shafts in a length of white plastic pluming pipe.  I added standard plastic screw on ends.
Inside there is rigid foam at the ends and a piece in between the two shafts.
It totally protects the shafts against all hazards, takes up little storage space, and aside from looking funny, works just fine.
clear skies,
fritz k


Re: Counterweight Shaft Travel Storage

fernandorivera3
 

A long time ago, way back when traveling to star parties & favorite dark sky sites was a normal routine <clearly prior to being locked up & boarded up thanks to the pandemic> I used a metallic tool box [obviously must be long enough to allow the counterweight shaft to fit inside]. I put my couple of weights on the bottom of the toolbox. Then a thick towel above the stainless steel weights. Finally the shaft rests on top. 
So that's how I would do it if taking my 1200 GTO (instead of one of my dobs) far away for a few days of viewing. It is a heavy lift if picking up the toolbox loaded up, around 70 pounds or so 😳

Fernando


Re: Counterweight Shaft Travel Storage

Fritz K
 

I have the 1100 shaft with extension.  I used to carry it in my counter weight box, but now that is too heavy for this old guy.
So I keep the shafts in a length of white plastic pluming pipe.  I added standard plastic screw on ends.
Inside there is rigid foam at the ends and a piece in between the two shafts.
It totally protects the shafts against all hazards, takes up little storage space, and aside from looking funny, works just fine.
clear skies,
fritz k


Re: Counterweight Shaft Travel Storage

John A. Sillasen
 

Oh that is interesting.  Where did you find some with a large enough ID and how do you keep it from disintegrating into dust or getting pieces on the threads?  The original box got a but beat up over time.



John A. Sillasen



Re: APCC pro refraction modeling for nomad setup #Mach2GTO #APCC

Dale Ghent
 

On May 12, 2021, at 09:30, Ray Gralak <iogroups@siriusimaging.com> wrote:

That said, you would get more accurate tracking with a model. The model will compensate for polar alignment error, flexure, and orthogonality errors. Typically APPM can run through 2-3 points per minute which would allow you to create a 60 point model in less than 30 minutes.
To add to Ray's comment, you can do the modeling run during twilight, usually during nautical dusk. Plate solving doesn't require anything in the way of fidelity; only that a sufficient number of stars can be detected. Doing it then will avoid stepping on your actual imaging time which, I presume, would start during astronomical dusk at the earliest.

/dale


Re: APCC pro refraction modeling for nomad setup #Mach2GTO #APCC

Ray Gralak
 

Hi Andrea,

 

> From what I have understood, APCC can take into account refraction when using a model.

> I wonder if it is possible to create a "transparent model", whose only effect would be to

> calculate refraction based on latitude, temp, humidity and celestial coordinates.

 

Yes, you can do that, but it would not take long to create a small model. If you have a model from a previous night that may no longer be valid, you can uncheck all of the pointing terms except the refraction checkbox, like in this screenshot, which shows a tracking rate correction for refraction only:

 

 

That said, you would get more accurate tracking with a model. The model will compensate for polar alignment error, flexure, and orthogonality errors. Typically APPM can run through 2-3 points per minute which would allow you to create a 60 point model in less than 30 minutes.

 

-Ray

 

> -----Original Message-----

> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Andrea Lucchetti

> Sent: Tuesday, May 11, 2021 3:25 PM

> To: main@ap-gto.groups.io

> Subject: [ap-gto] APCC pro refraction modeling for nomad setup #APCC #Mach2GTO

>

> Hi,

> I have a Mach2.

> From what I have understood, APCC can take into account refraction when using a model.

> I wonder if it is possible to create a "transparent model", whose only effect would be to calculate refraction based

> on latitude, temp, humidity and celestial coordinates.

>

> I have a nomad set up and prefer not to invest time in running a model, at least during summer when the night is

> very short .

> Thank you

> Andrea


Re: Counterweight Shaft Travel Storage

M Hambrick
 

Hi John

I use the Ridgid toolboxes. I lined them with the high density closed cell polyethylene foam in layers. You will have to take out the existing internal dividers that come with the boxes to do this. The lid is lined with a solid piece of 2" thick foam. The bottom of the case has a 1" thick solid layer. On top if that is a 2" thick layer with cutouts for the counterweights and shaft. The 2" foam is perfect for the 18 lb counterweights. There is a 1" thick spacer in the cutout with the 10 lb counterweight. I glued the layers together using contact cement.

In one of the cases I have two 18 lb counterweights. In the other I have the shaft with an 18 lb, and a 10 lb counterweight. This is a more or less even distribution of the weight in each case.

I have a bad back, but if I use proper lifting techniques I can carry one case in each hand to the mount.

Mike

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