Date   

Re: AP1100, Berlebach Planet, mounting CP4

Roland Christen
 

I have both an 1100 and a tripod so I will set them up and see what the clearances are both ways.

Roland

-----Original Message-----
From: ap@... <ap@...>
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Tue, May 18, 2021 11:47 am
Subject: Re: [ap-gto] AP1100, Berlebach Planet, mounting CP4

>>> Roland said:
 
Whether you put the 3rd leg pointing North or pointing South, the clearance of the other two legs will be about the same. In fact, you will have slightly more clearance for the telescopes when pointing at the zenith because the 1100 Dec axis hangs more northward of center. It is also the most stable condition for the mount with just counterweights attached.
 
That would be great if the clearance is better, as I do not really WANT to put the single leg south.  But with both my old CEM70G and current MyT that did give me several inches more clearance, enough I had no risk of collision (so long as I paid a bit of attention to rotation angle of the filter wheel), but definitely had collisions otherwise.
 
But if I can put the single leg North and still not have a collision issue, that would be terrific, as that almost doubles the available supported CG position.
 
Thank you.
 

--
Roland Christen
Astro-Physics


Re: AP1100, Berlebach Planet, mounting CP4

Roland Christen
 

I should have added that with the 3rd leg pointed northward, there is slightly more clearance for the telescope when it is pointing to the zenith.

Rolando



-----Original Message-----
From: Roland Christen via groups.io <chris1011@...>
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Tue, May 18, 2021 11:18 am
Subject: Re: [ap-gto] AP1100, Berlebach Planet, mounting CP4

Whether you put the 3rd leg pointing North or pointing South, the clearance of the other two legs will be about the same. In fact, you will have slightly more clearance for the telescopes when pointing at the zenith because the 1100 Dec axis hangs more northward of center. It is also the most stable condition for the mount with just counterweights attached.

Roland

-----Original Message-----
From: ap@... <ap@...>
To: main@ap-gto.groups.io
Sent: Tue, May 18, 2021 10:54 am
Subject: Re: [ap-gto] AP1100, Berlebach Planet, mounting CP4

As a follow on question with a Berlebach planet.

I received the mounting ring from Berlebach, and it emphasized how large the base of the AP1100 will be in comparison to this tripod.

I do not plan to have more than about 45 pounds of OTA, and counterweights of course. 

Does anyone with a similar setup have any kind of idea where the center of gravity is for that kind of setup?  Specifically how far off center?  

I typically image with the legs retracted fully for stability, and legs at closest are 9.5" (between legs) and 17" (at a single leg) from center.  I prefer to image with the single leg south not north, this provides a LOT more clearance (at least on my MyT) near zenith to avoid leg crashes.  But when I looked at that 9.5" it made me worry, this is a larger mount and probably different CG.

I found the Dimension Calculator spreadsheet, clearly aimed at clearance not load.  But I think (emphasis on think) that the point in the first image labeled as offset B, represents the BALANCED CG, basically at the intersection with the DEC axis.  

But what I am worried about is the unbalanced CG -- the point at which I have loaded 50# or so of counterweights and have yet to attach the OTA.  I.e. the situation why everyone says "put the single leg under the counterweight shaft".  Which is good advice I hope to not have to take so I don't hit the legs with my imaging train.

This all works fine on the MyT, it is quite stable.  But worried -- am I in for a rude surprise with the larger AP1100 (with 45# load)?  Yes, this is easy to figure out once I get it -- but if I need a new tripod/pier I'd like to get it on order now.

Anyone know where the CG is going to land?   And yes, I realize it's latitude dependent (I'm at 26d) but any real world experience welcome.

Linwood

--
Roland Christen
Astro-Physics

--
Roland Christen
Astro-Physics


Re: AP1100, Berlebach Planet, mounting CP4

ap@CaptivePhotons.com
 

>>> Roland said:

 

Whether you put the 3rd leg pointing North or pointing South, the clearance of the other two legs will be about the same. In fact, you will have slightly more clearance for the telescopes when pointing at the zenith because the 1100 Dec axis hangs more northward of center. It is also the most stable condition for the mount with just counterweights attached.

 

That would be great if the clearance is better, as I do not really WANT to put the single leg south.  But with both my old CEM70G and current MyT that did give me several inches more clearance, enough I had no risk of collision (so long as I paid a bit of attention to rotation angle of the filter wheel), but definitely had collisions otherwise.

 

But if I can put the single leg North and still not have a collision issue, that would be terrific, as that almost doubles the available supported CG position.

 

Thank you.

 


Re: Chasing a StarLink Satellite

Ray Gralak
 

Hi Brent,

Actually, you can turn off the caching of RA/Dec in APCC, but the option is not available in the user interface. APCC comes with an application called Horizons, which can track moving celestial objects and artificial satellites. Horizons turns off APCC caching when it is connected to the mount.

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Brent Boshart
Sent: Tuesday, May 18, 2021 9:08 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Chasing a StarLink Satellite

This is awesome! Was this with SkyTrack connected to the Mach2 via AP ASCOM driver or did you write a direct
interface?

That is with a direct interface. Unfortunately currently both the AP ASCOM driver and APCC have a limitation that
makes this accurate of tracking not possible. I use a loop that calculates difference between the satellite current
position and the mount's position to make small adjustments to the satellite's rate of movement in order to keep it
centered. Both the ASCOM driver and APCC poll the mount about once every second for its position instead of
sending "real time" data when its requested - fine for most applications. So if I am slewing at 3 deg/sec the
position I get from ASCOM/APCC could be a full second old and off by 3 degrees. My FOV in this video is only 1
degree. You can see in the video it does not stay exactly centered, that is pointing error because I only did a one
star sync for alignment. It would be nice to be able to use the APCC modelling. According to the position data I
receive comparing to the calculated satellite position, I am able to keep the satellite within 0.5 arcminutes of center,
the rest is calibration/pointing error.


Re: AP1100, Berlebach Planet, mounting CP4

Roland Christen
 

Whether you put the 3rd leg pointing North or pointing South, the clearance of the other two legs will be about the same. In fact, you will have slightly more clearance for the telescopes when pointing at the zenith because the 1100 Dec axis hangs more northward of center. It is also the most stable condition for the mount with just counterweights attached.

Roland

-----Original Message-----
From: ap@... <ap@...>
To: main@ap-gto.groups.io
Sent: Tue, May 18, 2021 10:54 am
Subject: Re: [ap-gto] AP1100, Berlebach Planet, mounting CP4

As a follow on question with a Berlebach planet.

I received the mounting ring from Berlebach, and it emphasized how large the base of the AP1100 will be in comparison to this tripod.

I do not plan to have more than about 45 pounds of OTA, and counterweights of course. 

Does anyone with a similar setup have any kind of idea where the center of gravity is for that kind of setup?  Specifically how far off center?  

I typically image with the legs retracted fully for stability, and legs at closest are 9.5" (between legs) and 17" (at a single leg) from center.  I prefer to image with the single leg south not north, this provides a LOT more clearance (at least on my MyT) near zenith to avoid leg crashes.  But when I looked at that 9.5" it made me worry, this is a larger mount and probably different CG.

I found the Dimension Calculator spreadsheet, clearly aimed at clearance not load.  But I think (emphasis on think) that the point in the first image labeled as offset B, represents the BALANCED CG, basically at the intersection with the DEC axis.  

But what I am worried about is the unbalanced CG -- the point at which I have loaded 50# or so of counterweights and have yet to attach the OTA.  I.e. the situation why everyone says "put the single leg under the counterweight shaft".  Which is good advice I hope to not have to take so I don't hit the legs with my imaging train.

This all works fine on the MyT, it is quite stable.  But worried -- am I in for a rude surprise with the larger AP1100 (with 45# load)?  Yes, this is easy to figure out once I get it -- but if I need a new tripod/pier I'd like to get it on order now.

Anyone know where the CG is going to land?   And yes, I realize it's latitude dependent (I'm at 26d) but any real world experience welcome.

Linwood

--
Roland Christen
Astro-Physics


Re: Chasing a StarLink Satellite

Brent Boshart
 

> This is awesome! Was this with SkyTrack connected to the Mach2 via AP ASCOM driver or did you write a direct interface?

That is with a direct interface.  Unfortunately currently both the AP ASCOM driver and APCC have a limitation that makes this accurate of tracking not possible.  I use a loop that calculates difference between the satellite current position and the mount's position to make small adjustments to the satellite's rate of movement in order to keep it centered. Both the ASCOM driver and APCC poll the mount about once every second for its position instead of sending "real time" data when its requested - fine for most applications.  So if I am slewing at 3 deg/sec the position I get from ASCOM/APCC could be a full second old and off by 3 degrees.  My FOV in this video is only 1 degree.  You can see in the video it does not stay exactly centered, that is pointing error because I only did a one star sync for alignment. It would be nice to be able to use the APCC modelling.  According to the position data I receive comparing to the calculated satellite position, I am able to keep the satellite within 0.5 arcminutes of center, the rest is calibration/pointing error.


Re: AP1100, Berlebach Planet, mounting CP4

ap@CaptivePhotons.com
 

As a follow on question with a Berlebach planet.

I received the mounting ring from Berlebach, and it emphasized how large the base of the AP1100 will be in comparison to this tripod.

I do not plan to have more than about 45 pounds of OTA, and counterweights of course. 

Does anyone with a similar setup have any kind of idea where the center of gravity is for that kind of setup?  Specifically how far off center?  

I typically image with the legs retracted fully for stability, and legs at closest are 9.5" (between legs) and 17" (at a single leg) from center.  I prefer to image with the single leg south not north, this provides a LOT more clearance (at least on my MyT) near zenith to avoid leg crashes.  But when I looked at that 9.5" it made me worry, this is a larger mount and probably different CG.

I found the Dimension Calculator spreadsheet, clearly aimed at clearance not load.  But I think (emphasis on think) that the point in the first image labeled as offset B, represents the BALANCED CG, basically at the intersection with the DEC axis.  

But what I am worried about is the unbalanced CG -- the point at which I have loaded 50# or so of counterweights and have yet to attach the OTA.  I.e. the situation why everyone says "put the single leg under the counterweight shaft".  Which is good advice I hope to not have to take so I don't hit the legs with my imaging train.

This all works fine on the MyT, it is quite stable.  But worried -- am I in for a rude surprise with the larger AP1100 (with 45# load)?  Yes, this is easy to figure out once I get it -- but if I need a new tripod/pier I'd like to get it on order now.

Anyone know where the CG is going to land?   And yes, I realize it's latitude dependent (I'm at 26d) but any real world experience welcome.

Linwood


Re: Chasing a StarLink Satellite

Luca Marinelli
 

Hi Brent,

 

This is awesome! Was this with SkyTrack connected to the Mach2 via AP ASCOM driver or did you write a direct interface?

 

Really nice work!

 

Luca

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Brent Boshart via groups.io
Sent: Tuesday, May 18, 2021 7:20 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Chasing a StarLink Satellite

 

[Edited Message Follows]

> How is the gamepad wired up?

The gamepad is not wired to the mount. It provides input to the software that calculates the satellite position.


Re: Chasing a StarLink Satellite

Roland Christen
 

WoW, super! Looks like the little satellite is dodging incoming missiles. Smile

Rolando


-----Original Message-----
From: Brent Boshart <bboshart@...>
To: main@ap-gto.groups.io
Sent: Tue, May 18, 2021 12:28 am
Subject: [ap-gto] Chasing a StarLink Satellite

First night out with my Mach2.  How is this for different - a StarLink satellite is a tight round dot and the stars are streaks... :)   The perpendicular movement at 00:24 is me making an adjustment with a gamepad - how fun is that?  Near the end of the video clip you can see the StarLink rotate. I'm looking forward to an ISS pass. 

https://www.youtube.com/watch?v=kDiPO-QuHPE

--
Roland Christen
Astro-Physics


Re: Chasing a StarLink Satellite

Karen Christen
 

That’s really fun.  It’s fascinating to see what folks can do with our equipment.  Thanks so much for sharing your video, Brent!

Karen

AP

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Brent Boshart
Sent: Tuesday, May 18, 2021 12:28 AM
To: main@ap-gto.groups.io
Subject: [ap-gto] Chasing a StarLink Satellite

 

First night out with my Mach2.  How is this for different - a StarLink satellite is a tight round dot and the stars are streaks... :)   The perpendicular movement at 00:24 is me making an adjustment with a gamepad - how fun is that?  Near the end of the video clip you can see the StarLink rotate. I'm looking forward to an ISS pass. 

https://www.youtube.com/watch?v=kDiPO-QuHPE


--
Karen Christen
Astro-Physics


Re: Chasing a StarLink Satellite

Dean Jacobsen
 

Nice Brent!  It looks like you are making excellent progress on the project.
--
Dean Jacobsen
Astrobin Image Gallery - https://www.astrobin.com/users/deanjacobsen/


Re: Chasing a StarLink Satellite

Brent Boshart
 
Edited

> How is the gamepad wired up?

The gamepad is not wired to the mount. It provides input to the software that calculates the satellite position.


Re: Chasing a StarLink Satellite

Jeffc
 

> making an adjustment with a gamepad

How is the gamepad wired up?

Fwiw, I've been using APPC "remote" with a laptop.
When I need to do something at the mount (e.g. last night for some reason I had to "re-initialize / calibrate"), it is a bit awkward to "push the buttons on the control window"... sure the laptop is wifi and very portable, but it is awkward to look through the viewfinder while pushing a virtual button using the trackpad.

I do have an AP keypad, but i rarely use it as I'm mostly / always using APCC these days.

Having a simple gamepad at the mount would be useful when I occasionally need to move the scope to center an object in the viewfinder.

Btw, I have a celestron four button keypad with RJ12 connector.. I've wondered if I can plug this into the guide port, set the rate appropriately, and use it for minor moves.

-jeff


On Mon, May 17, 2021 at 10:28 PM Brent Boshart <bboshart@...> wrote:
First night out with my Mach2.  How is this for different - a StarLink satellite is a tight round dot and the stars are streaks... :)   The perpendicular movement at 00:24 is me making an adjustment with a gamepad - how fun is that?  Near the end of the video clip you can see the StarLink rotate. I'm looking forward to an ISS pass. 

https://www.youtube.com/watch?v=kDiPO-QuHPE


Re: Chasing a StarLink Satellite

Christopher Erickson
 

Way cool!

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii


Virus-free. www.avg.com


On Mon, May 17, 2021 at 7:28 PM Brent Boshart <bboshart@...> wrote:
First night out with my Mach2.  How is this for different - a StarLink satellite is a tight round dot and the stars are streaks... :)   The perpendicular movement at 00:24 is me making an adjustment with a gamepad - how fun is that?  Near the end of the video clip you can see the StarLink rotate. I'm looking forward to an ISS pass. 

https://www.youtube.com/watch?v=kDiPO-QuHPE


Chasing a StarLink Satellite

Brent Boshart
 

First night out with my Mach2.  How is this for different - a StarLink satellite is a tight round dot and the stars are streaks... :)   The perpendicular movement at 00:24 is me making an adjustment with a gamepad - how fun is that?  Near the end of the video clip you can see the StarLink rotate. I'm looking forward to an ISS pass. 

https://www.youtube.com/watch?v=kDiPO-QuHPE


Re: Southern Owl Planetary nebula

skester@...
 

Wonderful capture Geoff!


Re: Southern Owl Planetary nebula

Roland Christen
 

Excellent!

Rolando



-----Original Message-----
From: Geoff Smith <ghsmith45@...>
To: main@ap-gto.groups.io
Sent: Mon, May 17, 2021 6:01 pm
Subject: [ap-gto] Southern Owl Planetary nebula

This is a seldom photographed object. However, it is quite large (3') and  bright (12.1).
Mount:AP900GTO
Camera: FLI Proline 16803
Telescope: 12.5" Planewave.
Processed in PixInsight.

Technical details here https://www.astrobin.com/onq3o6/
Larger res here https://www.astrobin.com/full/onq3o6/0/
Geoff

--
Roland Christen
Astro-Physics


Southern Owl Planetary nebula

Geoff Smith
 

This is a seldom photographed object. However, it is quite large (3') and  bright (12.1).
Mount:AP900GTO
Camera: FLI Proline 16803
Telescope: 12.5" Planewave.
Processed in PixInsight.

Technical details here https://www.astrobin.com/onq3o6/
Larger res here https://www.astrobin.com/full/onq3o6/0/
Geoff


Software Enhancement Requests Process?

Brent Boshart
 

Is there is a formal process for submitting software enhancement requests for the AP ASCOM driver or APCC?  Thanks.


Re: Counterweight Shaft Travel Storage

Barry Megdal
 

Strange – the one I made from Schedule 80 PVC is a good fit in the sense that the shaft slides in and out with a little “whoosh” of air, but not even close to getting stuck.

 

-        Barry

 

Dr. Barry Megdal

 

President

Shb Instruments, Inc.

19215 Parthenia St.  Suite A

Northridge, CA 91324

www.shbinstruments.com

(818) 773-2000  (818)773-2005 fax

bmegdal@...

 

Faculty (retired)

Dept. of Electrical Engineering

Caltech

 

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