Date   

Re: Which GTOCP* connection do you use?

Dale Ghent
 

GTOCP3 here, so USB direct from my NUC-like miniPC to a 14 year old Prolific-based USB to serial adaptor that plugs into the CP3. Somehow, this old adaptor has managed to survive winters and summers outdoors under nothing more than a Telegizmos 365 cover and it still manages to do its job just fine. The only thing I've have do to in terms of maintenance is to take some pliers and pinch in the D-sub housing a bit so that it maintains a good grip on the CP3's female DB9 port.

When the 1100GTO that is on order arrives, I'll likely do direct USB. Same if I decide to upgrade the CP3 on my Mach1 to a CP4, but that's unlikely at this point in light of the pending arrival of the 1100. Ethernet's cool and all, but it's not needed for range (it's 1 wire-meter max. between miniPC and the CP's location) and USB will probably do just fine given my insistence on using non-trash cables and securing them such that the connectors never take any mechanical strain.

As for Wifi, there's more room for failure and there are a few special considerations, at least in my case. My miniPC's wifi is already on my home wifi network, so the CP's wifi radio would need also need be on the same SSID, thus putting all communication between my miniPC and the CP through one of my 2 meshed access points back inside the house. Additionally, the CP would be mounted on the south side of my pier and its transmission and reception would be blocked by the pier and mount as my house and the access points are to the north of my pier. ATS piers excel at many aspects of doing the job of a telescope pier, and I'm sure attenuating 2.4/5GHz wifi is also something that it's adept at doing. So I'm not going to go there. It just doesn't offer me any advantages over a ~1m direct USB connection.

On Mar 14, 2021, at 21:28, cargostick@gmail.com wrote:

A new poll has been created:

I am toying with connecting via ethernet to save a USB space on my control computer. I have also ordered an FTDI serial adapter to try that out. Therefore I should only need 1 USB cable to my entire imaging rig. What are your connections and why?

1. USB
2. Ethernet
3. WiFi
4. RS-232

Vote Now

Do not reply to this message to vote in the poll. You can vote in polls only through the group's website.


Re: Slide Rules and Slipsticks - in the 1960's B.C. - i.e. (Before Computers)

Richard O'Neill <syzygy42@earthlink.net> <syzygy42@...>
 

I still have my Pickett rules, A pocket size 6" and two 12", all in leather cases. Surprisingly, after more than fifty years I still remember how to use most of the scales!

Richard


Which GTOCP* connection do you use?

Roger Howard
 

I am toying with connecting via ethernet to save a USB space on my control computer.  I have also ordered an FTDI serial adapter to try that out.  Therefore I should only need 1 USB cable to my entire imaging rig.  What are your connections and why?

Results

See Who Responded


Re: Counter weight up slew vs. continuing past the meridian, any real differences?

Luca Marinelli
 
Edited

On Sun, Mar 14, 2021 at 10:07 AM, Ray Gralak wrote:
Hi Luca,

It's not a big deal either way; we are only talking about two or three slews per target. But then again, neither is a
Meridian flip, which also take a couple of slews per target for plate solving. That was my original point.
Can you clarify? Are you saying that SGPro needs to slew two or three times in the course of platesolving a new target, and in the process of doing this APCC is doing a pier flip and multiple safe slews for the *same* target?

-Ray

When I set up a target in SGP, I'll enter RA and DEC coordinates for the center of the image, as well as rotation angle of the frame. I start the evening with a "closed loop slew" to use TSX terminology to the target. The precision I require for the centering process is 30 points maximum error, which translates to roughly 20 arc-sec. If I am not running a model on the Mach2 or the AP1100, the "closed loop slew"  to the target will usually take 2-3 slews. The first gets you within half a degree to a degree of the target, depending on its position in the sky, and the second one gets you perfectly there or almost. If I am using a model, depending on where the target is in the sky, it will take 1-2 slews to get there.

If I allow APCC to run counterweight up slews within East limits and if the target is within East limits, when SGP issues the first slew command to center the target, the mount will go in a CW up position with the scope on the East side pointing East. When I have been next to the mount I have observed that the next slew or two to refine the position of the mount and meet the required precision for centering the frame will be safety slews.

The same holds for meridian flips. After issuing the slew command that triggers the meridian flip, SGP will run a platosolve task to confirm the correct position of the target. Typically, it will then issue a second and rarely a third slew to center the target with 20 arc-sec precision. The slews after a meridan flip will not be safety slews because they are CW down.

My observation was that in theory starting from a CW up position saves imaging time, in practice I have found the opposite because safety slews take longer. That's all I was saying. Again, this is an entirely minor difference and overall minute contribution to overhead compared to time spent focusing, dithering, saving files, etc. If you relax the precision requirement, obviously it will take fewer slew to get the frame centered. I image targets over the course of several months and require this precision so I don't have to trim the edge of the frames excessively.

If there is a better way to set up APCC to reduce this time overhead, I am always looking for ways to improve how the software works together.

Luca


Re: Backlash

Mike Dodd
 

On 3/14/2021 5:28 PM, Tom Blahovici wrote:
I have this mount and use it for imaging.
Which mount would that be?

I have backlash of 2 seconds in Dec....
My mount had a 2.8 arc second peak to peak periodic error without PEC.
Periodic error has nothing to do with Dec, only RA. If your mount requires Dec corrections, that indicates your polar alignment should be adjusted.

Dec adjustments should be infrequent. Do your Dec corrections need the same 2-second backlash in both directions, or only one? IOW, is the correction with the backlash the same in both directions?

If so, it sounds to me like your work-to-worm-wheel mating is too loose, and needs adjusting. If not, that sounds like a balance issue, which would manifest itself only while pointing to certain areas of the sky.

--- Mike


Re: Backlash

Tom Blahovici
 

I have this mount and use it for imaging. Balance seems to be really important but a bit difficult to do.
I have backlash of 2 seconds in Dec and when I image with Voyager, it takes a couple of starts to get rid of it. Once gone there is no issue.
It is actually a really nice mount and is rock solid for my FSQ106 with Moonlite Nitecrawler and camera setup.  Certainly better than a Losmandy G11 I used to have.
In any case, it is not difficult to adjust the backlash but does take a while. There's a manual on this on the AP website.
My mount had a 2.8 arc second peak to peak periodic error without PEC.
Tom


Re: Backlash

thefamily90 Phillips
 

Fantastic! No imaging planned.
Thank you!

JimP


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Roland Christen via groups.io <chris1011@...>
Sent: Sunday, March 14, 2021 3:41:46 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Backlash
 
Backlash will be on the order of arc second, so it realistically won't have any effect on pointing. It can also be mitigated on that mount with careful adjustment, however it is really only important if you want to image and guide during imaging.

Roland



-----Original Message-----
From: thefamily90 Phillips <thefamily90@...>
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Sun, Mar 14, 2021 2:10 pm
Subject: [ap-gto] Backlash

Thinking about purchasing an AP 600 E GOTO for visual observations of double stars with my AP 155 F/7. Everything about the Mount sounds good except the seller says it has significant declination backlash. As I will be using the GOTO function and searching for doubles using the RA/DEC coordinates on the keypad I am concerned about being able to align properly using 2-3 stars. Here’s what I found. Any thoughts 

JimP
Image.jpeg



--
Roland Christen
Astro-Physics


Re: Backlash

Roland Christen
 

Backlash will be on the order of arc second, so it realistically won't have any effect on pointing. It can also be mitigated on that mount with careful adjustment, however it is really only important if you want to image and guide during imaging.

Roland



-----Original Message-----
From: thefamily90 Phillips <thefamily90@...>
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Sun, Mar 14, 2021 2:10 pm
Subject: [ap-gto] Backlash

Thinking about purchasing an AP 600 E GOTO for visual observations of double stars with my AP 155 F/7. Everything about the Mount sounds good except the seller says it has significant declination backlash. As I will be using the GOTO function and searching for doubles using the RA/DEC coordinates on the keypad I am concerned about being able to align properly using 2-3 stars. Here’s what I found. Any thoughts 

JimP
Image.jpeg



--
Roland Christen
Astro-Physics


Backlash

thefamily90 Phillips
 

Thinking about purchasing an AP 600 E GOTO for visual observations of double stars with my AP 155 F/7. Everything about the Mount sounds good except the seller says it has significant declination backlash. As I will be using the GOTO function and searching for doubles using the RA/DEC coordinates on the keypad I am concerned about being able to align properly using 2-3 stars. Here’s what I found. Any thoughts 

JimP
Image.jpeg



Re: Counter weight up slew vs. continuing past the meridian, any real differences?

Marcelo Figueroa
 


I just let SGP handle the meridian flips on its own (I have these settings disabled in APCC, too lazy to set them up right), it works perfect every time with a Mach2 on a single attempt.
 
The only time it has failed was in a cloud attack that prevented SGP from doing its plate solving.


Re: Counter weight up slew vs. continuing past the meridian, any real differences?

Michael 'Mikey' Mangieri
 

SGP sometimes needs three slews to get on target. I have found in the past that my scope did in fact due three meridian flips when trying to plate solve.

On Mar 14, 2021, at 10:07 AM, Ray Gralak <iogroups@siriusimaging.com> wrote:

Hi Luca,

It's not a big deal either way; we are only talking about two or three slews per target. But then again, neither is a
Meridian flip, which also take a couple of slews per target for plate solving. That was my original point.
Can you clarify? Are you saying that SGPro needs to slew two or three times in the course of platesolving a new target, and in the process of doing this APCC is doing a pier flip and multiple safe slews for the *same* target?

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Luca Marinelli
Sent: Sunday, March 14, 2021 6:56 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Counter weight up slew vs. continuing past the meridian, any real differences?

On Sat, Mar 13, 2021 at 05:29 PM, Ray Gralak wrote:


Luca,



How would I set up APCC so that slews within the East limits with CW up from SGP do not invoke
safety slews?

If the SGPro move is 0.5 degrees or less in Declination then there will be no safety slew.

-Ray




Thanks, Ray. So if I read your statement correctly, there is no special setting in APCC that will avoid safety slews
within the meridian limits but if the slew issued is close enough in Dec, then APCC will simply nudge the mount to
the right place, without going back to CW down first.

It's not a big deal either way; we are only talking about two or three slews per target. But then again, neither is a
Meridian flip, which also take a couple of slews per target for plate solving. That was my original point.

Luca





Re: Counter weight up slew vs. continuing past the meridian, any real differences?

Ray Gralak
 

Hi Luca,

It's not a big deal either way; we are only talking about two or three slews per target. But then again, neither is a
Meridian flip, which also take a couple of slews per target for plate solving. That was my original point.
Can you clarify? Are you saying that SGPro needs to slew two or three times in the course of platesolving a new target, and in the process of doing this APCC is doing a pier flip and multiple safe slews for the *same* target?

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Luca Marinelli
Sent: Sunday, March 14, 2021 6:56 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Counter weight up slew vs. continuing past the meridian, any real differences?

On Sat, Mar 13, 2021 at 05:29 PM, Ray Gralak wrote:


Luca,



How would I set up APCC so that slews within the East limits with CW up from SGP do not invoke
safety slews?

If the SGPro move is 0.5 degrees or less in Declination then there will be no safety slew.

-Ray




Thanks, Ray. So if I read your statement correctly, there is no special setting in APCC that will avoid safety slews
within the meridian limits but if the slew issued is close enough in Dec, then APCC will simply nudge the mount to
the right place, without going back to CW down first.

It's not a big deal either way; we are only talking about two or three slews per target. But then again, neither is a
Meridian flip, which also take a couple of slews per target for plate solving. That was my original point.

Luca


Re: Counter weight up slew vs. continuing past the meridian, any real differences?

Luca Marinelli
 

On Sat, Mar 13, 2021 at 05:29 PM, Ray Gralak wrote:
Luca,

How would I set up APCC so that slews within the East limits with CW up from SGP do not invoke safety slews?
If the SGPro move is 0.5 degrees or less in Declination then there will be no safety slew.

-Ray


Thanks, Ray. So if I read your statement correctly, there is no special setting in APCC that will avoid safety slews within the meridian limits but if the slew issued is close enough in Dec, then APCC will simply nudge the mount to the right place, without going back to CW down first.

It's not a big deal either way; we are only talking about two or three slews per target. But then again, neither is a Meridian flip, which also take a couple of slews per target for plate solving. That was my original point.

Luca


Re: Slide Rules and Slipsticks - in the 1960's B.C. - i.e. (Before Computers)

Joe Zeglinski
 

    I think the note above Von Braun’s slide rule is appropriate.
Recall the movie sequence in APOLLO-13, Tom Hanks is asking mission control to double check his gimbal angle corrections. The scene shows the guy on the desk giving a thumbs up after verifying with his K&E slide rule. One man with a slide rule can do wonders. They had an IBM-7094 but no calculators for that? Rescue hinged on a slide rule.
 
    Certainly reinforced my respect for the ground control team, and what could be done without massive computers.
 
Joe
 

From: Eric Dreher
Sent: Saturday, March 13, 2021 3:00 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Slide Rules and Slipsticks - in the 1960's B.C. - i.e. (Before Computers)
 
Having grown up during the Mercury launches onward, my childhood hero became Wernher von Braun.  During a 2016 visit to the Cosmosphere Space Museum in Hutchinson, Kansas, I spotted a slide rule in a glass display case.  For obvious reasons, I had to take a photo.


Re: Counter weight up slew vs. continuing past the meridian, any real differences?

Ray Gralak
 

Luca,

How would I set up APCC so that slews within the East limits with CW up from SGP do not invoke safety slews?
If the SGPro move is 0.5 degrees or less in Declination then there will be no safety slew.

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Luca Marinelli
Sent: Saturday, March 13, 2021 2:09 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Counter weight up slew vs. continuing past the meridian, any real differences?

Ray,

How would I set up APCC so that slews within the East limits with CW up from SGP do not invoke safety slews? Is
it in the APCC manual?

Thanks,

Luca

On Mar 13, 2021, at 12:19 PM, Ray Gralak via groups.io <iogroups=siriusimaging.com@groups.io> wrote:



Earlier this week it was mentioned that
due to how SGP commands the mount during a plate solve/center, starting counter weight up invokes the safety
slew thus making very small adjustments quit slow.
APCC has a variety of meridian limit configuration settings. When setup appropriately, counterweight-up slews
within APCC's meridian limits will not do safety slews, and thus do not result in extra time in SGPro. However, if
SGPro issues a move outside of the meridian limits then a pier flip will occur.

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of skester@gmail.com
Sent: Saturday, March 13, 2021 9:02 AM
To: main@ap-gto.groups.io
Subject: [ap-gto] Counter weight up slew vs. continuing past the meridian, any real differences?

I've seen many comments about the ability of AP mounts to slew to a counterweight up position with the scope
on
the east side, so that you can avoid the flip and continue west. Assuming I want to track the target from -3hrs to
+3hrs of the meridian, how if at all is this different to starting with a normal slew with the scope on the west side,
and
ending in the counter weight up position (assuming clearance of course)? Earlier this week it was mentioned that
due to how SGP commands the mount during a plate solve/center, starting counter weight up invokes the safety
slew thus making very small adjustments quit slow. It would seem a solution would be to just reverse the
process
and end rather than start counter weight up. Am I missing something here?







Re: Counter weight up slew vs. continuing past the meridian, any real differences?

Luca Marinelli
 

Ray,

How would I set up APCC so that slews within the East limits with CW up from SGP do not invoke safety slews? Is it in the APCC manual?

Thanks,

Luca

On Mar 13, 2021, at 12:19 PM, Ray Gralak via groups.io <iogroups=siriusimaging.com@groups.io> wrote:



Earlier this week it was mentioned that
due to how SGP commands the mount during a plate solve/center, starting counter weight up invokes the safety
slew thus making very small adjustments quit slow.
APCC has a variety of meridian limit configuration settings. When setup appropriately, counterweight-up slews within APCC's meridian limits will not do safety slews, and thus do not result in extra time in SGPro. However, if SGPro issues a move outside of the meridian limits then a pier flip will occur.

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of skester@gmail.com
Sent: Saturday, March 13, 2021 9:02 AM
To: main@ap-gto.groups.io
Subject: [ap-gto] Counter weight up slew vs. continuing past the meridian, any real differences?

I've seen many comments about the ability of AP mounts to slew to a counterweight up position with the scope on
the east side, so that you can avoid the flip and continue west. Assuming I want to track the target from -3hrs to
+3hrs of the meridian, how if at all is this different to starting with a normal slew with the scope on the west side, and
ending in the counter weight up position (assuming clearance of course)? Earlier this week it was mentioned that
due to how SGP commands the mount during a plate solve/center, starting counter weight up invokes the safety
slew thus making very small adjustments quit slow. It would seem a solution would be to just reverse the process
and end rather than start counter weight up. Am I missing something here?





Re: APCC shows Altitude at 0 in Park 3

Bill Long
 

Good find. Nothing like sleeping to clear your mind and find the answer.


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Wayne Hixson via groups.io <wayneh9026@...>
Sent: Saturday, March 13, 2021 9:31 AM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] APCC shows Altitude at 0 in Park 3
 
Glad it was easy to rectify. Later today I’m going to enter my Home coordinates in the keypad!

Thanks again

Wayne
> On Mar 13, 2021, at 9:23 AM, Ray Gralak <iogroups@...> wrote:
>
> Hi Wayne,
>
>> I assume it was just behaving as expected and the APCC values don’t override the keypad values when it’s set to
>> auto connect to ON? I suspect I hadn’t run into this before because my keypad values were all correct?
>
> Yes, if the keypad initializes the mount, then APCC will not initialize the mount, so your Mach2 continues to use the keypad's Lat/Long values.
>
> Once Lat/Long has been set, you have to power-cycle the mount to change it.
>
> -Ray
>
>> -----Original Message-----
>> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Wayne Hixson via groups.io
>> Sent: Saturday, March 13, 2021 9:18 AM
>> To: main@ap-gto.groups.io
>> Subject: Re: [ap-gto] APCC shows Altitude at 0 in Park 3
>>
>> Hi guys! Tried that several times and no go, but my subconscious evidently worked on the problem in my sleep.
>> First thing when I got up I checked the hand controller and it was as set to Auto Connect On and the site information
>> was set to Lat and Long 00 00 00. I changed to Connect EXT and power cycled. Then opened APCC. For a split
>> second, ALT went to 0, but then set to the correct value equal to my latitude.Yay! But now it’s cloudy!!
>>
>> I assume it was just behaving as expected and the APCC values don’t override the keypad values when it’s set to
>> auto connect to ON? I suspect I hadn’t run into this before because my keypad values were all correct?
>>
>> Wayne
>>
>
>
>
>
>
>







Re: Slide Rules and Slipsticks - in the 1960's B.C. - i.e. (Before Computers)

Eric Dreher
 

Having grown up during the Mercury launches onward, my childhood hero became Wernher von Braun.  During a 2016 visit to the Cosmosphere Space Museum in Hutchinson, Kansas, I spotted a slide rule in a glass display case.  For obvious reasons, I had to take a photo.


Re: Need to Invert PE curve before loading into Mach1GTO?

Keith Egger
 

Thanks Roland. So I’ll assume that re-meshing has no effect on PE then. Good to know. 

Keith


Re: Need to Invert PE curve before loading into Mach1GTO?

Roland Christen
 


am I correct that re-meshing the worm gear doesn't require redoing the PEC?
Yes, that is correct.

Rolando


-----Original Message-----
From: Keith Egger <eggerk@...>
To: main@ap-gto.groups.io
Sent: Sat, Mar 13, 2021 11:40 am
Subject: [ap-gto] Need to Invert PE curve before loading into Mach1GTO?

Having finished my re-greasing, which involved removing the motors, I had to redo my PEC. I ran 6 worm cycles in PEMPro last night and generated a PE curve this morning. In the workflow PEMPro says to load the curve, then run a couple of cycles and if the PE is doubled, Invert the curve and reload. I didn't have time to load the curve last night and check, so does the Mach1GTO need the PE curve to be inverted before loading or not?

Another question, am I correct that re-meshing the worm gear doesn't require redoing the PEC? Does re-meshing have any effect on the periodic error at all, as in increasing or decreasing?

thanks,
Keith

--
Roland Christen
Astro-Physics

5301 - 5320 of 82278