2 star alignment doesn't work


G-man
 

I did setup the mount, polar scope aligned to polaris, leveled, adjusted all the axis etc, but when I tell it to do a 2 star alignment from a perfectly aligned position, it asks for a star but it slews to some random piece of sky, nowhere near where the star is supposed to be. Yes, I load the GPS coordinates. Any help why this doesn't work?

Thanks.


Jerry Hubbell - Explore Scientific VP Engineering
 

Hi Guillermo,

There are a couple things you should check to make sure they are correct in addition to the longitude and latitude. The longitude must be a negative value if it is WEST longitude, i.e., -77.7106 for my location in Virginia. Also the time must be set to within a few seconds with the proper time zone set on the computer. for every minute the clock is off, the scope will point 1/4 degree off in Right Ascension.

Please check those items.

I would also suggest that you clear the alignment and with your good physical polar alignment slew to a bright object such as a bright star and let me know how far off it is in your finder.

Thanks

--
Jerry Hubbell
Vice President of Engineering

Explore Scientific, LLC.
jrh at explorescientific.com

www.explorescientificusa.com
1010 S. 48th Street
Springdale, AR 72762
1-866-252-3811

Author: Scientific Astrophotography: How Amateurs Can Generate and Use Professional Imaging Data
             Remote Observatories for Amateur Astronomers: Using High-Powered Telescopes From Home




Robert Parks
 

I have randomly experienced this as well.  I bet you're running Android version of Explore Stars App, right?  I do this:

Level and polar align Mount.

Affix telescope.  Balance  Check if I'm still polar aligned after the jostling.

Release clutches and set to the park position aligning the arrows on the mounts RA and DEC axes.

Look again after the jostling.

Plug in PMC 8

Wait a minute. 

Set tablet to connect to PMC 8 WIFI.

Open Explore Stars.

LOAD GPS

Confirm correct lat and long for my location.

Confirm Mount set to "EXOS II"

RESET ALIGNMENT

Confirm alignment data at 0's

Then I commence the two or three star alignment.

If it slews to a random part of the sky, I use the "PARK" button to return to home position.  "STOP ALIGNMENT" "RESET ALIGNMENT" Confirm 0"s. Try again.

It seems to take a couple of tries every time I set up for it to just start working.  Probably user error (I'm a rank noob). 

If the gurus have any pointers or see obvious flaws in my process I'd love guidance and/or correction. Hope this helps.

Robert Scott Parks
Northwest Arkansas USA
ES 127 Triplet Refractor
EXOS II-GT with PMC-8
Explore Stars on Samsung Tab A




On Sun, Dec 30, 2018, 3:32 AM <garciasampedrogj@... wrote:
I did setup the mount, polar scope aligned to polaris, leveled, adjusted all the axis etc, but when I tell it to do a 2 star alignment from a perfectly aligned position, it asks for a star but it slews to some random piece of sky, nowhere near where the star is supposed to be. Yes, I load the GPS coordinates. Any help why this doesn't work?

Thanks.


Jerry Hubbell - Explore Scientific VP Engineering
 

Hi Robert,

Thanks for your input on this problem, this is the first I have heard of this problem and its relation to the Android version of ExploreStars.  I will check this out with my Android tablet to see if I can repeat it also. If Guillermo is using the Android app then that would be good to know also.

Thanks

--
Jerry Hubbell
Vice President of Engineering

Explore Scientific, LLC.
jrh at explorescientific.com

www.explorescientificusa.com
1010 S. 48th Street
Springdale, AR 72762
1-866-252-3811

Author: Scientific Astrophotography: How Amateurs Can Generate and Use Professional Imaging Data
             Remote Observatories for Amateur Astronomers: Using High-Powered Telescopes From Home




G-man
 

Hey, sorry for not answering sooner... but we just woke up 20 mins ago, we were stargazing (fighting the mount?) up until 6:35 am. Now, I am blown away with the ES ED80 APO, I knew it was good, but man oh man...  it puts the Mak90 to shame... I was able to, even with somewhat crappy atmospheric conditions, to see perfectly the phase of Venus, no fringing and some limited contrast on the cloud layer. The moon was sharp and bright as heck, but by the time we gave up on the mount it was too late to see anything else worth pointing the scope at.

Yes, I am using the Android version, which doesn't seem to match what I've seen on the videos showcasing the ExploreStars App.

For GPS Coordinates I have -89.55 West (for Wisconsin, Madison) Lat is 43.05. I don't see any alignment data in the settings menu. Where am I supposed to look for that? Thanks.

The Tablet is running the apk that you can download from the Explore Scientific site, as my tablet runs a custom barebones ROM (rooted, Cyanogenmod 13) and has no Play Store installed. The ExploreStars APK version I am running is 1.0.18099.354 [85643] and the link to the apk I used is here: http://02d3287.netsolhost.com/pmc-eight/Android.html

Thanks guys! I can't wait!

G.


G-man
 

Hey Robert, thanks for the input. So, I did try a similar approach, not the same tho, reset the alignment multiple times, even restarted tablet..., etc, but I found out the Park button never returned the mount to where it was first connected to. I first set the mount down, adjust ALT-AZ using the polar scope to get a good enough alignment for visual, then I lock the mount axes RA and DEC where the arrows meet, so its in neutral north position before there is even power to the PMC-8 controller. Power the controller, wait a few seconds the load the app, reset everything, and I hit park, and for some reason it starts moving to some random location.

G.


G-man
 

Okay, so I think I've figured this out... I did setup the mount inside my home office. Roughly polar aligned it using SkyMap, fired controller, reset app, ensured the park button returns to normal, etc, ... etc. Everything seemed to check out, park returns to zero, all stuff zeroed out, etc. Start the process on the 2 star alignment and the same thing last night... it slews goes to some random piece of sky where the Leo constellation is supposed to be. So, I fire up Stellarium on my main PC, to find out where Leo is supposed to be be during the day... and the constellation just went under the horizon... that was an eureka moment, so, if the constellation just went under the horizon how is it possible that the tablet still thinks its up in the air? First thing was check the time and it seemed to be off by 1 hour behind... proceed to change and while adjusting the time of the day I realized that the tablet's actual date was set to January, of the year 2000... HA.... needless to say, I did set the time date and proceeded to reset the whole thing again, verified park returns, etc... and when the 2 star alignment starts, now I am getting the mount to point pretty accurately towards the constellation of Ursa Major, even though I can't confirm with real stars yet, the phone SkyMap app certainly agrees with where the mount is now pointing at. I'll set it up again tonight, but I suspect the issue has been taken care of.

So, moral of the story, besides the fact that I am a such a beginner for not checking the first thing in astronomy... the date, I think it would be nice to have some sort of help button that says [STAR NOT HERE], that if clicked brings a pop-up or some sort of help text stating to check for the correct date and time on the tablet/PC. 

Thanks guys! I'll keep you posted on how this unfolds tonight.

G.


Wes Mcdonald
 

I use the app ClockSync to set the Android Tablet time and date.  It goes out to an NTP server.  Also have GPS Time which is an app that will get time from GPS.  It is good for field work where you have sky access but not network.  But it requires a rooted Android to automatically set the time..but you can do pretty well using it to manually set time.

Wes.


G-man
 

My tablet is rooted, running Cyanogenmod 13 (Android 6.0) its the only thing I use it for (explorestars)

G.


G-man
 

and if something can go wrong, it WILL go wrong, now I can't verify that the mount works until freaking coming Wednesday b/c of the FRAKING CLOUDS... sometimes I wonder why the heck I came to live to Cloudsconsin.. its just worthless... nothing frustrates more than freaking CLOUDS, regardless of what I am trying to do. Now, does anybody have a good radio-telescope I can borrow?

G.


Jerry Hubbell - Explore Scientific VP Engineering
 

Hi Guillermo,

I am glad you figured out the issue. I thank you for sharing your find as it can be a bit embarrassing sometimes to find a simple mistake. It's new customers like you that I really appreciate and am happy are on this forum. Your issue will make it easier for other beginners to get their system working right the first time.

Thanks again, and Clear Skies!!

--
Jerry Hubbell
Vice President of Engineering

Explore Scientific, LLC.
jrh at explorescientific.com

www.explorescientificusa.com
1010 S. 48th Street
Springdale, AR 72762
1-866-252-3811

Author: Scientific Astrophotography: How Amateurs Can Generate and Use Professional Imaging Data
             Remote Observatories for Amateur Astronomers: Using High-Powered Telescopes From Home




G-man
 

Well, so I got the thing to work. The darn clouds heard my cursing and gave me a 2 hour clear skies window before the main cloud body from the north came and shut us down.

So, while the mount did work, I felt a few things were lacking... specially how inconsistent it is, very erratic. For example, the values, parameters, etc, don't clear out unless you restart the controller and kill the app. It doesn't have a CLEAR ALL button that forces all parameters to just powered up state, regardless of anything. Alignment buttons should be in the main screen, b/c having to drill 2 menus to get to it is a real PITA (and when its 20F outside its even more annoying) Alignment shouldn't slew the mount until you chose the star you want to align it to. Since this is an open loop controller, every move performed adds errors in the integration, so there is absolutely no reason to start slewing the mount until I say, YES, this is the star I want to align to. So, instead of start slewing with a Sync button it should be a remain where it is and show an [Align] button, and then, once I determine this is the star I want to align to, I press the [Align] button and it proceeds to slew, and then switches the [Align] button to [Sync[ then you can adjust the mount to point to the star. The next issue I noticed is that if you quickly skip stars it seems to lose its brains and you have to redo it all over again. So, say you chose Deneb to align, you hit [Sync], then it gives you another star that its behind the house so you can't point at it... so skip it, then the next, also unreachable, so skip quick, skip and skip, until it gives me say, Sirius but by now the mount can't find it, it goes into some sort of wackadoo drunken mount move that ends up pointing the telescope down into the ground, and you're back to square one: Power down the PMC-8, kill process app from Android task manager, restart PMC-8, restart app, ensure park and the rest of the things are all zeroed out. Then try again with the alignment, if you get lucky the drunken goto mount won't happen... but so far I've had to redo the aligment more times than I want to, when its 20F outside having to deal with the hardware rather than actually watching the skies is very frustrating.

Then the AdHoc network seems to disappear/reset/stop once in a while, specially so if you allow the tablet to sleep... it is almost guaranteed it will lose its brains and will leave you having to redo it all over again, not fun. But once you get the system aligned, it sort of works... but after trying a few times to get the alignment without a hitch, then the GoTos are very inaccurate, and I am not a master of the skies, I have some general knowledge of where most of the big things are... but I would expect that after doing a 2 star alignment the system should pinpoint the Orion nebula, when in reality it was off by a large enough margin that someone who doesn't know where to look will never find it. To give you an idea how far off the Orion nebula was, in a 9x50 finderscope it was half way between the reticle crosshair and the edge of the viewfinder.

I might have to try the ASCOM and forget the app altogether, but if the app is giving this many problems/bugs, I am not sure how the ascom is going to magically fix these issues.

G.


Jerry Hubbell - Explore Scientific VP Engineering
 

I can assure you the system does work accurately as designed and as demonstrated by dozens of our customers every day. There can be issues with the wireless connection if you are in a crowded WiFi traffic area, that is why we provide the WiFi channel change dongle. The Windows ExploreStars user interface may be more to your liking as all the menu items are available on the main display with the touch of a button, not as in the Android version of the program. I am sorry you are having these issues, but I am sure you will get them resolved.
 
--
Jerry Hubbell
Vice President of Engineering

Explore Scientific, LLC.
jrh at explorescientific.com

www.explorescientificusa.com
1010 S. 48th Street
Springdale, AR 72762
1-866-252-3811

Author: Scientific Astrophotography: How Amateurs Can Generate and Use Professional Imaging Data
             Remote Observatories for Amateur Astronomers: Using High-Powered Telescopes From Home




G-man
 

Unfortunately I won't be able to use the mount again until Wed, most likely.

I don't understand, (well I actually do, but whatever) why the different versions of the app have different interfaces...  maybe the Android version was the lame duck... and I don't have a Windows tablet. So looks like it is ASCOM for me at this time, why bother with the ES app. 

The mount hardware seems to be very well designed, I have zero complains on the actual mount, but since the brains of the system are in the app, I guess the app is whats lacking... and once again I should move to the ASCOM to save myself from all these annoyances.

As for the accuracy issue, I've read something about it on other threads, so it seems I am not alone on that respect. Perhaps it requires a perfect polar alignment to work, or perhaps it doesn't work at 20F b/c the friction, perhaps the app is just lacking... I am not sure... but what I can tell you is what I've done, and so far, with a decent polar alignment + two star alignment the thing is off when slewing to the Orion nebula.

Now, since so many customers have managed to get this to work pinpoint accurate, I would love to hear the magic sauce to get this working.

Thanks.

G.


G-man
 

Well, I'll be darned, forget fighting the ExploreStars app... I just got the ASCOM driver and Stellarium to work, simply put, there is no comparison. I've been using Stellarium for years now... but didn't know it was this awesome with a telescope.... just click on a star, hit CTRL-1 and off it goes. You even get to see where the telescope is looking at, in real time, while its slewing... hot dang! it almost feels like aiming a SAM missile battery control station. Not bad.
I assume this will require a good alignment with multiple stars once its under the actual sky, but I'll figure that part out soon enough. At least this setup does what the app couldn't do, which is produce consistent results that don't vary every time you restart the controller, or some random dropout. With Stellarium, after slewing across the entire skydome it always returns to the exact same Polaris position (the parked position), it has never pointed the telescope to the ground a single time like the app did, never got confused when changing slews while on the fly, and I've already tested over 300 different stars, all kinds of agility tests, go from A to B, but half way back to Polaris, back to that, etc... the thing seems rock solid (as expected), so I guess my grips really are with the ExploreStars app, it just pales in comparison to the real deal, so forget the app and here is what you need to do to to get Stellarium up and running.
-Follow the PMC-Eight instructions to get the ASCOM driver installed. As of the writing of this post the instructions DO work, I just followed them and got the ASCOM driver operational. 
-Download Stellarium and StellariumScope, yes you'll need the later too, Stellarium won't work without it, I've tried, it just sits there forever connecting.
So, download StellariumScope and Stellarium.
Install Stellarium and run it to ensure it works.
In the Configuration window there is a Plug-ins tab, find the Telescope Control, its at the end, and there is a checkbox that says, load at startup, enable it.
Close Stellarium.
Now Install StellariumScope, you'll be greeted by an error window, dismiss it.
Set the mount to ASCOM_ES_PMC8_whatevername but don't check the connect just yet.
Select use J2000, leave Host as LOCALHOST
Telescope label I set it to EXOS2
Leave all the other stuff default, 
Then hit Update Stellarium Configuration.
And now select the Connect checkbox.
Then click the Start Stellarium button.
Once its up and running you'll see the yellowish/orangeish LED on the PMC-8 controller start to blink, that means its talking to the laptop. 
As soon as the orangeish LED blinks on the PMC controller you'll see a large dark orange crosshair in Stellarium, that is where your telescope is currently pointed at.
Select a star and hit CTRL-1, the telescope will now slew towards the star you've selected.
Repeat this in awe as many times while watching the thing slew like a missile launcher ready to fire!!

I haven't used this under the sky yet, but if this is as repeatable and as consistent as it has shown on my tests, I don't think alignment will be a problem, so long the scope always slews to the same place when you click on the same star.

Cheers.
G.


AstroObsessed
 

G,
I have found Stellarium with Stellarium Scope to work very well with the PMC-8. 

Also using Astrophotography Tool (APT) with plate solving to be very good as well.

You will find success using either under a clear sky.


G-man
 

That is awesome!! Thanks man! Greatly appreciated. Lol, clear sky... not much of that during winter in Cloudsconsin... LOL. I have Nikon DSLR and all the gear to get into astrophotography, but there something about seeing things with my naked eye or Gen3 night vision, real time, that cameras just don't have, for me at least,.. but who knows, maybe I'll jump into astrophotography at some point. :)

G.


Robert Parks
 

G.

Thanks for the detailed instructions on installing and configuring Stellariam!

On Mon, Dec 31, 2018, 3:09 AM <garciasampedrogj@... wrote:
That is awesome!! Thanks man! Greatly appreciated. Lol, clear sky... not much of that during winter in Cloudsconsin... LOL. I have Nikon DSLR and all the gear to get into astrophotography, but there something about seeing things with my naked eye or Gen3 night vision, real time, that cameras just don't have, for me at least,.. but who knows, maybe I'll jump into astrophotography at some point. :)

G.


Harry
 

Hi Jerry, I recently purchased an iExos 100 PMC Eight Mount, and use the iPAD version of ExploreStars. I have been closely following the accuracy and alignment discussions, and basically have the same issues. I have 2 points I would like your input.

First is alignment. I use a physical/visual polar alignment with my AR102 and ES 82’ 20mm eyepiece. Time, date, GPS coordinates all checked. Polaris centered in eyepiece, and mount adjusted as necessary. Home position done. I then attempted a 2 or 3 star alignment, which is very difficult with my location and seeing conditions. Go To accuracy was terrible. Scope all over the sky. Last night I used the same Polar alignment technique, but NO further 2 or 3 star alignment. 
This was based on the following quote from the iExos instruction manual:

NOTE: The 2 and 3 Star Alignment process provides a “virtual” polar alignment versus doing a “physical” polar alignment. It is important to understand the difference.

Well, my go to accuracy was much, much improved! Slewed to several objects. They generally were just outside my FOV of my eyepiece, but were then tweaked and then synced. M42 remained centered. What is the difference, and for visual use, is a 2/3 star alignment necessary?

Secondly, when I choose an object from any catalog, and select “slew to object”, it responds normally. I then 
“sync”. Also available on the screen is the option “Go To” for the same object. What’s the fifference? When do you 
use “Go To”?

Thank you, HarryB


Jerry Hubbell - Explore Scientific VP Engineering
 

Hi Harry, 

Thanks for you purchase, you are the first iEXOS 100 customer I have talked with. Generally, the 2 and 3-star alignment will improve the pointing of your scope even with the physical polar alignment off by a few degrees. It is always better to do a physical polar alignment within 1 degree of the pole, this can be accomplished by aligning on Polaris. Once that is done, a 3-star alignment is better in that it not only corrects for the misalignment between the celestial coordinate system and mount coordinate system, but also corrects for cone angle. Cone angle is the offset between your telescope and the mount. There are typically cone angle adjustments on the dovetail on the telescope. 

We are aware of a couple of problems with the iOS version of ExploreStars and are working to correct those and get the new version out on the Apple App Store as soon as we can. I will let everyone know when the updated version is available. Having said that, I am not sure why the scope would be "all over the sky" as you say. We have other customers using the iOS version with no mention of this problem. Perhaps someone that has had success with the iOS version of ExploreStars can chime in here. Unfortunately, I have not been able to test the iOS version of the app as I do not currently have an iPAD.

When you choose an object from the catalog the goal is to GOTO that object, so the primary purpose for that page is to slew to the object. You would only utilize the SYNC when you know you have the object centered in your eyepiece. You do not want to hit the SYNC button before slewing to the object because it would then tell your mount to reset the coordinates to the object when in fact you may be far off that object. Subsequent slews to objects would be way off and may be the cause of your scope being "all over the sky", I am not sure. Again, I cannot test this for myself.

I hope that answers your questions. Please review the PMC-Eight Knowledge Base on the Explore Scientific website and utilize the search tool to narrow down your topic to specific articles.

Thanks again Harry for your purchase, I look forward to hearing more about your experience with the new iEXOS 100 PMC-Eight mount and your AR102.

Clear Skies!

Jerry Hubbell
Vice President of Engineering

Explore Scientific, LLC.
jrh at explorescientific.com

www.explorescientificusa.com
1010 S. 48th Street
Springdale, AR 72762
1-866-252-3811

Author: Scientific Astrophotography: How Amateurs Can Generate and Use Professional Imaging Data
             Remote Observatories for Amateur Astronomers: Using High-Powered Telescopes From Home