Date   

Re: AP1100 autoguiding

Howard Hedlund
 

Hi Christophe,

Congratulations on acquiring the 1100GTO.  You will love it!

Pointing errors can have several sources:
  • The most common cause of pointing errors is polar misalignment.
  • If the RAPAS was not properly calibrated, it may not give good results.  If it was calibrated incorrectly, it will certainly fail to give good pointing.
  • Orthogonality affects pointing, especially nearer to the pole.  Orthogonality problems show themselves most strongly after a meridian flip.
  • Pointing problems are almost never the fault of the mount.
As Oliv points out, one of the first things to determine is whether your drift is in RA, Dec or in both axes.  You can easily determine which direction on the chip is RA by stopping tracking for a short while in the middle of an image.  The streak that results will be in the direction of RA.

You will need to either create a good PE curve or autoguide.  If you received the copy of PEMPro that came with the mount, you can both cure the periodic error and fix the polar alignment at the same time.

You may or may not need to remesh the gears.  This can be quite easily tested using the instructions in our website's technical support section.  https://astro-physics.info/tech_support/mounts/gear-mesh-1600-1100-mach1-2014-10-24.pdf 

Contact me at Astro-Physics for further assistance.

Howard


Re: AP1100 autoguiding

OlivDeso
 

p.s. pointing and drift are 2 different subjets

- drift along DEC is related to polar alignment (so a pure mecanical topic)
- pointing is related to the calibration of the pointing model. (mainly a software synchronisation subject)


Le lundi 2 mai 2022, 19:00:37 UTC+2, OlivDeso <olivdeso@...> a écrit :


Hello Christophe

The pointing is usually 15-20 arcmin off, on any target in the sky, and, last night, I tried to image M101, and saw that the derive is something like 30" per hour on such a target. The max exposure time I could do was 60sec at 1900 mm focal length.


by "dérive" which is the French word, do you mean drift I guess, so you get trailling stars.

Do you know I which direction? RA? DEC? or both?

Drift along DEC -> polar align is not good enough  -> perform a very acurate drift aligment using pempro, then fine tune the rapas
Drift along RA axis -> PE -> perform gear remeshing, then PE measurement with pempro and then upload PEC from pempro to the mount


There are 2 things to do to improve the PE :

1) gear re-meshing : first of all, before any PE measurement, it is very important to have a proper gear meshing, especially if the mount has travelled and/or was used at a different temperature.

-> follow the AP procedure here, it isvery simple and very efficient.




On to of that, I 'd like to mention a trick : on the forst AP1100, I found the CP3 motor spring loader to be a little bit to strong. It fact it comes from the screw which secure the spring : the thread is a little bit too short compared to the spring length. Not a big deal for DEC, but significant for RA.

My advise : on these older AP1100, while tuning the RA mesh, unscrew the spring holding screew by 2 turns, not more. and follow the AP procedure.
It will ensure applying just the needed pressure to get the best meshing and lowest EP.
Once this gear meshing is done, you can 

2) Once gear mesh has been properly set, you can run pempro and measure the PE.
- first polar align precisely enough, using the drift alingment tool
- measure the PE between +1° and +5° after the meridian, not more. "rewind" if needed



Are the RJ11-6 and RJ12 plugs compatible ? -> yes, in fact RJ11 is the 4 contacts version of the RJ12 

(RJ11 6 positions 4 contact (6p4c) and RJ12 6p6c. So RJ11-6 is a wrong naming, the right naming is RJ12 for 6p6c RJ plug)

Now since you have the CP4 ou CP3, you could also use the pulse guiding whicjh is a little bit more acurate than the ST4 : the mount itself manages the pulse duration. Thought in this particular case, the difference is likely to be marginal with the Lacerta Mgen. (it could be more signigficant with an old PC)


clear skies

Oliv Deso
Le lundi 2 mai 2022, 05:26:56 UTC+2, christopheciel via groups.io <christopheciel@...> a écrit :


Dear all,


My name is Christophe, from France.

This is my first message here.

My english is not very good, as you will see ; I hope you will understand what I mean.


This forum is a great idea.


**


I bought a used 1100 GTO a few months ago from a very nice person, who had it in a small observatory.

This precedent owner had a CP3, then he bought a CP4. He never actualized the PEM, so there is none, using only the mount with a PC and an autoguiding camera to image.


After a couple of weeks of use, I still have some issue with the pointing and tracking. I use only the keypad. The pointing is usually 15-20 arcmin off, on any target in the sky, and, last night, I tried to image M101, and saw that the derive is something like 30" per hour on such a target. The max exposure time I could do was 60sec at 1900 mm focal length.


I calibrated the RAPAS as indicated in the rapas notice, and the mount is leveled as perfectly as I could.


Well, I'm now looking for an autoguiding camera in order to enhance the tracking.


I have a old LACERTA MGEN stand alone autoguiding camera.


https://en.lacerta-optics.com/MGEN_Lacerta-MGEN-II-Superguider-Autoguider-Camera-with


The out plug of this system is an ST4 or RJ12 male plug. I understand that the autoguiding female plug on the CP4 is a RJ11-6 plug.


Are the RJ11-6 and RJ12 plugs compatible ?


So had some of you ever used a same lacerta mgen system on a 1100 GTO ? Do you think this is possible ?


Or should I avoid to use this camera and buy another on ? I have a limited budget right now, alas.


Thank you so much for any help or advice.


Christophe



Re: AP1100 autoguiding

OlivDeso
 

Hello Christophe

The pointing is usually 15-20 arcmin off, on any target in the sky, and, last night, I tried to image M101, and saw that the derive is something like 30" per hour on such a target. The max exposure time I could do was 60sec at 1900 mm focal length.


by "dérive" which is the French word, do you mean drift I guess, so you get trailling stars.

Do you know I which direction? RA? DEC? or both?

Drift along DEC -> polar align is not good enough  -> perform a very acurate drift aligment using pempro, then fine tune the rapas
Drift along RA axis -> PE -> perform gear remeshing, then PE measurement with pempro and then upload PEC from pempro to the mount


There are 2 things to do to improve the PE :

1) gear re-meshing : first of all, before any PE measurement, it is very important to have a proper gear meshing, especially if the mount has travelled and/or was used at a different temperature.

-> follow the AP procedure here, it isvery simple and very efficient.




On to of that, I 'd like to mention a trick : on the forst AP1100, I found the CP3 motor spring loader to be a little bit to strong. It fact it comes from the screw which secure the spring : the thread is a little bit too short compared to the spring length. Not a big deal for DEC, but significant for RA.

My advise : on these older AP1100, while tuning the RA mesh, unscrew the spring holding screew by 2 turns, not more. and follow the AP procedure.
It will ensure applying just the needed pressure to get the best meshing and lowest EP.
Once this gear meshing is done, you can 

2) Once gear mesh has been properly set, you can run pempro and measure the PE.
- first polar align precisely enough, using the drift alingment tool
- measure the PE between +1° and +5° after the meridian, not more. "rewind" if needed



Are the RJ11-6 and RJ12 plugs compatible ? -> yes, in fact RJ11 is the 4 contacts version of the RJ12 

(RJ11 6 positions 4 contact (6p4c) and RJ12 6p6c. So RJ11-6 is a wrong naming, the right naming is RJ12 for 6p6c RJ plug)

Now since you have the CP4 ou CP3, you could also use the pulse guiding whicjh is a little bit more acurate than the ST4 : the mount itself manages the pulse duration. Thought in this particular case, the difference is likely to be marginal with the Lacerta Mgen. (it could be more signigficant with an old PC)


clear skies

Oliv Deso

Le lundi 2 mai 2022, 05:26:56 UTC+2, christopheciel via groups.io <christopheciel@...> a écrit :


Dear all,


My name is Christophe, from France.

This is my first message here.

My english is not very good, as you will see ; I hope you will understand what I mean.


This forum is a great idea.


**


I bought a used 1100 GTO a few months ago from a very nice person, who had it in a small observatory.

This precedent owner had a CP3, then he bought a CP4. He never actualized the PEM, so there is none, using only the mount with a PC and an autoguiding camera to image.


After a couple of weeks of use, I still have some issue with the pointing and tracking. I use only the keypad. The pointing is usually 15-20 arcmin off, on any target in the sky, and, last night, I tried to image M101, and saw that the derive is something like 30" per hour on such a target. The max exposure time I could do was 60sec at 1900 mm focal length.


I calibrated the RAPAS as indicated in the rapas notice, and the mount is leveled as perfectly as I could.


Well, I'm now looking for an autoguiding camera in order to enhance the tracking.


I have a old LACERTA MGEN stand alone autoguiding camera.


https://en.lacerta-optics.com/MGEN_Lacerta-MGEN-II-Superguider-Autoguider-Camera-with


The out plug of this system is an ST4 or RJ12 male plug. I understand that the autoguiding female plug on the CP4 is a RJ11-6 plug.


Are the RJ11-6 and RJ12 plugs compatible ?


So had some of you ever used a same lacerta mgen system on a 1100 GTO ? Do you think this is possible ?


Or should I avoid to use this camera and buy another on ? I have a limited budget right now, alas.


Thank you so much for any help or advice.


Christophe



AP1100 autoguiding

christopheciel
 

Dear all,


My name is Christophe, from France.

This is my first message here.

My english is not very good, as you will see ; I hope you will understand what I mean.


This forum is a great idea.


**


I bought a used 1100 GTO a few months ago from a very nice person, who had it in a small observatory.

This precedent owner had a CP3, then he bought a CP4. He never actualized the PEM, so there is none, using only the mount with a PC and an autoguiding camera to image.


After a couple of weeks of use, I still have some issue with the pointing and tracking. I use only the keypad. The pointing is usually 15-20 arcmin off, on any target in the sky, and, last night, I tried to image M101, and saw that the derive is something like 30" per hour on such a target. The max exposure time I could do was 60sec at 1900 mm focal length.


I calibrated the RAPAS as indicated in the rapas notice, and the mount is leveled as perfectly as I could.


Well, I'm now looking for an autoguiding camera in order to enhance the tracking.


I have a old LACERTA MGEN stand alone autoguiding camera.


https://en.lacerta-optics.com/MGEN_Lacerta-MGEN-II-Superguider-Autoguider-Camera-with


The out plug of this system is an ST4 or RJ12 male plug. I understand that the autoguiding female plug on the CP4 is a RJ11-6 plug.


Are the RJ11-6 and RJ12 plugs compatible ?


So had some of you ever used a same lacerta mgen system on a 1100 GTO ? Do you think this is possible ?


Or should I avoid to use this camera and buy another on ? I have a limited budget right now, alas.


Thank you so much for any help or advice.


Christophe



Re: re greasing worm wheel on 1100GTO original gearbox.

Dan_Paris
 

As  someone else noticed in a recent thread, the Aeroshell 33 composition may have changed recently but the present one contains dialkyl sulphide (safety data sheet updated in 2021). Is there a danger for brass and bronze gears?

As an alternative, the Molykote 33 seems easy to get in Europe.




Re: Too Windy to Go Long?

Dean Jacobsen
 

Thanks Terry and Roland.

On Sat, Apr 30, 2022 at 05:00 PM, Roland Christen wrote:
How well does this scope cover a full frame 35mm camera, ZWO6200?
I honestly don't know.  The secondary isn't very big -- about 2" diameter looking from the front of the scope.  I don't own a full frame camera any more.  I was surprised that the APS-C camera works as well as it does with the Baader MPCC.  I thought I would end up using my 4/3" camera [ASI294MM] or have to get a 1" sized camera for this scope, or end up cropping my images.  The stars aren't perfect across the entire detector with the APS-C camera but they are plenty good for me.
 
--
Dean Jacobsen
Astrobin Image Gallery - https://www.astrobin.com/users/deanjacobsen/


Re: Too Windy to Go Long?

Terry Martin
 

Very nice Dean.


Re: Too Windy to Go Long?

Roland Christen
 

Nice indeed!

How well does this scope cover a full frame 35mm camera, ZWO6200?

Roland

-----Original Message-----
From: Dean Jacobsen <deanjacobsen@...>
To: main@ap-gto.groups.io
Sent: Sat, Apr 30, 2022 6:39 pm
Subject: Re: [ap-gto] Too Windy to Go Long?

I was able to get out for an overnight session.  This time I used the 1000mm fl f/6 Newtonian and got some egg shaped stars due to light winds.  I discarded the worst ones but kept some.

https://www.astrobin.com/full/fk07uk/0/

An annotated version:

https://www.astrobin.com/full/fk07uk/B/

Equipment - ASI2600MC Pro with the Takahashi MT-160 at f/6 (using Baader MPCC).  Carried by the Mach2.  60 x 240 second exposures.  Unguided.

--
Dean Jacobsen
Astrobin Image Gallery - https://www.astrobin.com/users/deanjacobsen/

--
Roland Christen
Astro-Physics


Re: Too Windy to Go Long?

Dean Jacobsen
 

I was able to get out for an overnight session.  This time I used the 1000mm fl f/6 Newtonian and got some egg shaped stars due to light winds.  I discarded the worst ones but kept some.

https://www.astrobin.com/full/fk07uk/0/

An annotated version:

https://www.astrobin.com/full/fk07uk/B/

Equipment - ASI2600MC Pro with the Takahashi MT-160 at f/6 (using Baader MPCC).  Carried by the Mach2.  60 x 240 second exposures.  Unguided.

--
Dean Jacobsen
Astrobin Image Gallery - https://www.astrobin.com/users/deanjacobsen/


Re: Need help identifying Counterweight shaft stop to buy

M Hambrick
 

Actually, they do still sell these. The price is a little higher now. You might need to keep the large washer that you used for the stop on your 1.875-inch shaft.


Re: Need help identifying Counterweight shaft stop to buy

M Hambrick
 

Hi again George

It might be worth checking with Astro-Physics to see if they still have any of the machined safety stop knobs that fit the old counterweight shafts that used the 5/16-18 thread for the stop. The catalog number was MSSKB.

I bought one of these in late 2016 to use on my old 800 mount. The cost was $27.00. As with all things Astro-Physics, the quality is excellent, and the machined aluminum is much more durable than the phenolic knobs.

Mike


Re: re greasing worm wheel on 1100GTO original gearbox.

sroberts84
 

Remove the leading "." in (before "http") and the link will work.

---
We've got fifteen minutes, Freddo, it's worse than I thought!


Re: re greasing worm wheel on 1100GTO original gearbox.

gmiller2005@...
 

Hmm, I tried the link I provided and it didn't work. Search for the My Pilot Store website and then type in Aeroshell33.


Re: re greasing worm wheel on 1100GTO original gearbox.

gmiller2005@...
 

Here's where I got my tube of Aeroshell, in stock.
.https://www.mypilotstore.com/MyPilotStore/sep/11518?utm_source=bing&utm_medium=cpc&utm_campaign=bing-shopping&msclkid=121bf6a838141c35a04394c44dcb069b


Re: NGC 4030, a seldom imaged galaxy

Karen Christen
 

That’s a super-pretty galaxy, Geoff!  Lots of other interesting tidbits in there, as well.  Nice work!

Karen

AP

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Geoff Smith
Sent: Friday, April 29, 2022 1:47 AM
To: main@ap-gto.groups.io
Subject: [ap-gto] NGC 4030, a seldom imaged galaxy

 

I was able to find only one amateur image of this galaxy, which is quite strange considering its size (4 arcminutes) and brightness (mag 10.6). I would have expected that its location in Virgo would have made it a target for both northern and southern imagers. So one image on IIS, none on astrobin, no reference in any of the popular "what can I image" catalogues.


The weird thing is that I imaged it in 2017 and 2018 then forgot about it and never got around to processing it. There must be some sort of conspiracy to keep it hidden.



The image is here https://www.astrobin.com/ajvnzj/

Usual equipment: AP900, Plane Wave 12.5", FLI 16803 Proline. Processed in PixInsight.



NGC 4030 is a grand design spiral galaxy in Virgo, lying about 64 million light years.
In 2007, a supernova explosion was discovered in the galaxy from images taken on February 19 from the 1 m Swope telescope at Las Campanas Observatory in Chile The progenitor was a red giant star with 8.5–16.5 times the mass of the Sun.
See an image of the supernova here https://www.iceinspace.com.au/forum/...light=ngc+4030

This was the only amateur image of NGC 4030 that I could find.


--
Karen Christen
Astro-Physics


Re: NGC 4030, a seldom imaged galaxy

fernandorivera3
 

Nice image 👍🔭

Fernando


Re: Upgrading GTOCP3 "J" chip to V2 Post steps

Steven Panish
 

George,
It's been a couple years but as I recall the brief signon message on the hand controller tells you the version.  I have 4.17 and don't recall having to do anything special after upgrading to V2 in the CP3.  I don't use the handbox much so I've never upgraded it.
Steve

On Thu, Apr 28, 2022 at 11:38 PM George Lutch <glutch@...> wrote:
I just upgraded the chip in the GTOCP3 from "J" version to "V2".  Instructions say that I must reinitialize either via the hand controller or computer connection.  How do I tell what version of firmware is on the hand controller as it says for version 4.17 and older do one thing while if it's 4.19 or newer do another. 



--
PLEASE NOTE MY NEW EMAIL ADDRESS!!!
Due to Google eliminating cheap domain serving, Virginia and I are changing to regular gmail addresses.  The old panishnet address will forward to this address for a short while, but please add the new address, scpanish1@..., to your contact list.


Re: Need help identifying Counterweight shaft stop to buy

Dan Folz
 

I can confirm that the bolt size is 5/16-18. I recently replaced a broken phenolic knob with whats shown below.
Hope this helps!

Dan

On Friday, April 29, 2022, 05:24:25 AM CDT, M Hambrick <mhambrick563@...> wrote:


I believe that the threads on the stop are 5/16-18, but someone from A-P can confirm this. Do you have a bolt with the same threads that you can try in the shaft ?

Mike


Re: Need help identifying Counterweight shaft stop to buy

Howard Ritter
 

Or take the shaft to Home Depot and try either their thread template or bolts from the specialty cabinet. I’ve found that strategy very useful!

—howard

On Apr 29, 2022, at 6:24 AM, M Hambrick <mhambrick563@...> wrote:

I believe that the threads on the stop are 5/16-18, but someone from A-P can confirm this. Do you have a bolt with the same threads that you can try in the shaft ?

Mike


Re: Need help identifying Counterweight shaft stop to buy

M Hambrick
 

I believe that the threads on the stop are 5/16-18, but someone from A-P can confirm this. Do you have a bolt with the same threads that you can try in the shaft ?

Mike

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