Takahashi EM11 Temma2 Jr goes wrong on GOTO

[JayMS]

Hi,

At last, I bought Takahashi EM11 Temma2 Jr which is famous for one of the best equatorial mounts. But I have a little worry about its age 
Through the test I've found that
even the slew speed of mount is quite slow, but it's quite stable and other operations such as azimuth and altitude adjustment for polar alignment, focus control is very smooth.
I could feel more than one level higher, comparing to the previous light mount with 5kg payload.

In general I am very satisfied except one thing.
Here are what I did at last night:
After polar aligning using SharpCap & guide camera only with the mount power-off, the mount positioned toward NCP apparently.
And I turned on the mount to recognize this position to NCP as the home position.
And then I executed ATP and Stellarium, I tried to slew to famous stars to focus more accurately.
However
when I executed the goto to an object in APT and Stellarium such as Deneb, Vega etc,
the destination always deviated to the target quite far away even though I'd correctly entered required information for latitude, longitude,altitude in the mount property at the begining.

Attached files are related to this;
(After polar aligning using SharpCap & guide camera with the mount power-off, the mount positioned toward NCP apparently.)
For test purpose I just tried to do goto to Polaris/NCP using Stellaruim (Find Polaris and press down ctr+1),
however strangely the mount started to move and located to other position in right below corner.

I attached relevant pictures
- Pic 1. Mount property setting at connection
- Pic 2. Actual telescope location right after polar aligning, shown in Stellarium (You can find the telescope location in left upper corner)
- Pic 3. After goto Polaris for test, Stellarium showed the telescope location was same as Polaris, but actual positioning of real mount went toward around M31 right below of Polaris.

Please advise me why it happened and what I have to do to solve this problem.

Best regards,

James 

[Stuart1971]

What is your question….?

[Steve Ward]

Probably an incorrectly entered 'Time' or 'Time zone' or 'Daylight Saving' information .

Were you by any chance about 15 degrees off target ? 

[JayMS]

@Stuart1971
Big deviation to the target after goto, which might cause the pointcraft failure.
I'd like to know what I did wrong, and what I have to do to slew to the target exactly.

Edited July 3, 2022 by JayMS

[JayMS]

@Steve Ward
@teoria_del_big_bang
To Steve, 
I can't find a place to put in such information Tme/Time Zone etc. Where is it?
In the mount property box, there is no place for them.
I am not sure, It varied depending on the target.

Edited July 3, 2022 by JayMS

[Cosmic Geoff]

I am not familiar with your mount, but I do not  see any indication above that you performed a goto alignment at any time. Typically this entails entering the date and time and geographical position, and fine-aiming the telescope at one, two, or three bright alignment stars.  A mechanical polar alignment is only part of the process.  This full process has to be mastered before using software like ATP and Stellarium.

[davew]

Hi James,

I'll try and answer your questions but I have to say I'm not as modern as you 🙂 I've never used APT with the Tak mount and certainly never used Sharpcap ! Not only that but I've not used an EM11 either. What I have used is an EM200 Temma 2 and it's pretty much the same other than the size and the Polar Reticule.

I always used the integrated Polar Scope to align and once all was set up I connected the mount and made sure all the parameters were set properly. Looking at your ASCOM connection all seems well and I assume you've used Sharpcap correctly too.

I always started weights down and scope pointing approximately in the direction of the pole and then in the planetarium section of your software told it to point at a known star. I can perhaps put your mind at rest here as it NEVR EVER centred the star in quite a few years of my use ! What you do then is point the scope at the intended star ( I used to do it manually ) and then the most important bit - Sync to the star in your software. That then gives a 1 star alignment which is all I ever used and I'm not aware that a 2 or 3 star alignment is possible.

Now to check if all is well what you can do is tell the scope to point at say Deneb. Sync. Tell the scope to point at Vega. If you've polar aligned ok then it will centre on Vega. Then tell it to point at Altair and it should do that ok too. If it still won't work then your polar alignment is probably out so try the polar scope. If you try a Meridian flip then you'll have to sync on your intended star again.

That Ascom driver was written by an American guy called Chuck Faranda and on his Temma page there is a short manual of how to use it. Even if you use another app looking at what he's written could be a good idea - https://ccdastro.net/Temma Driver.pdf

Once you have this simple technique nailed down you can use plate solving to sync your scope to the night sky. I just used the simplest alignment methods and was able to manage over 30 minutes guided with no problems.

Any more problems and I'll try to help but not with software.

Dave.

 

 

 

[JayMS]

19 hours ago, Cosmic Geoff said:

I am not familiar with your mount, but I do not  see any indication above that you performed a goto alignment at any time. Typically this entails entering the date and time and geographical position, and fine-aiming the telescope at one, two, or three bright alignment stars.  A mechanical polar alignment is only part of the process.  This full process has to be mastered before using software like ATP and Stellarium.

Hi Cosmic Geoff,
Thanks for your guide. Last night I did three star alignment with sync.

This time I did Sync right after PA, and first goto Deneb worked well which was different from the previous and did the first Sync in APT.
But second goto Altair deviated much, so I made it centered by hand controller which was time consuming, quite annoying but good experience for naviagation control :) and did the second Sync in APT.
And third goto Vega also deviated less much, so I did same thing to make it centered and did the third Sync in APT.

And I went back to Home position/NCP to test goto at the starting point.
And goto M33 after the successful retrying of 3 stars alignment, at last M33 was centered through plate solving process of Pointcraft. I was so happy to realize my mount is fine.

But one thing remained to solve.
After some test shooting of M33, I tried to goto M31 which is near, but it went to a wrong direction so I stopped the mount compulsorily.
So for the initialization  I turned off and restarted all.
And tried to goto M33 again, this time it worked well.
I don't know why it happened. Can this kind of thing happen sometimes?

Anyway I made a good progress.
I'd like to appreciate your advise.
Best regards,
James

Edited July 4, 2022 by JayMS

[JayMS]

13 hours ago, davew said:

Hi James,

I'll try and answer your questions but I have to say I'm not as modern as you 🙂 I've never used APT with the Tak mount and certainly never used Sharpcap ! Not only that but I've not used an EM11 either. What I have used is an EM200 Temma 2 and it's pretty much the same other than the size and the Polar Reticule.

I always used the integrated Polar Scope to align and once all was set up I connected the mount and made sure all the parameters were set properly. Looking at your ASCOM connection all seems well and I assume you've used Sharpcap correctly too.

I always started weights down and scope pointing approximately in the direction of the pole and then in the planetarium section of your software told it to point at a known star. I can perhaps put your mind at rest here as it NEVR EVER centred the star in quite a few years of my use ! What you do then is point the scope at the intended star ( I used to do it manually ) and then the most important bit - Sync to the star in your software. That then gives a 1 star alignment which is all I ever used and I'm not aware that a 2 or 3 star alignment is possible.

Now to check if all is well what you can do is tell the scope to point at say Deneb. Sync. Tell the scope to point at Vega. If you've polar aligned ok then it will centre on Vega. Then tell it to point at Altair and it should do that ok too. If it still won't work then your polar alignment is probably out so try the polar scope. If you try a Meridian flip then you'll have to sync on your intended star again.

That Ascom driver was written by an American guy called Chuck Faranda and on his Temma page there is a short manual of how to use it. Even if you use another app looking at what he's written could be a good idea - https://ccdastro.net/Temma Driver.pdf

Once you have this simple technique nailed down you can use plate solving to sync your scope to the night sky. I just used the simplest alignment methods and was able to manage over 30 minutes guided with no problems.

Any more problems and I'll try to help but not with software.

Dave.

 

 

 

Hi Davew, First of all I'd like to appreciate your detail comments.

Last night I did three star alignment with SYNC like your comments, as I described in reply message to Cosmic.

Question.
Is it O.K. to adjust it manually instead of using hand controller in order to make the star centered? It's not easy for me to navigate on RA and DEC using hand controller.
Do you think that to do Sync right after PA made impact to goto the first star correctly, because this time  anyway the first goto was successful after that.
And 
any idea why Goto M31 after M33 failed even after three star alignment and successful goto M33?

Thanks for your kind help,
James

 

Edited July 4, 2022 by JayMS

[Cosmic Geoff]

JayMS - can you confirm that the mount works properly when operated according to the user manual without the computer connection and with the handset?  If it doesn't there is no point in trying to use APT etc.

I am not sure what you mean by sync.  You might find it useful to explain that in more detail.

6 hours ago, JayMS said:

Is it O.K. to adjust it manually instead of using hand controller in order to make the star centered? It's not easy for me to navigate on RA and DEC using hand controller.

Moving the mount manually rather than via the GoTo handset is usually a no-no.  It should be easy enough to centre the star with the hand controller if you can see it on screen - just press the direction buttons till you hit the ones that move it in the right direction. That may sound dumb but it's just how it is. (With an alt-azimuth mount one can predict what the buttons are going to do.)

Again, I am not familiar with your mount, but most GoTo mounts work in a similar manner, and some may use essentially the same software as more popular brands.

[davew]

Hi James,

I've finally remembered why I didn't do a 2 or 3 star alignment. All to do with the encoders but as I don't know if your Temma control is the same as mine, I'll stand back and let Geoff guide you. He probably knows more about APT than me.

Good luck,

Dave.

[JayMS]

15 hours ago, Cosmic Geoff said:

JayMS - can you confirm that the mount works properly when operated according to the user manual without the computer connection and with the handset?  If it doesn't there is no point in trying to use APT etc.

I am not sure what you mean by sync.  You might find it useful to explain that in more detail.

Moving the mount manually rather than via the GoTo handset is usually a no-no.  It should be easy enough to centre the star with the hand controller if you can see it on screen - just press the direction buttons till you hit the ones that move it in the right direction. That may sound dumb but it's just how it is. (With an alt-azimuth mount one can predict what the buttons are going to do.)

Again, I am not familiar with your mount, but most GoTo mounts work in a similar manner, and some may use essentially the same software as more popular brands.

Hi Cosmic,
Takahashi EM11 Temma2 Jr's hand controller only has a simple function to slew in RA and DEC direction, so without the computer connection there is no way to perform GOTO.
If you intend that "the mount works properly" means "Slew in RA and DEC direction as I want", Yes it does.
I meant that SYNC is to press a SYNC button of APT gear tap menu in order to match the current position of the mount with internal coordinate for the designated object.

[Cosmic Geoff]

Having looked up the specs, I see what you mean. Despite the eye-watering price, the mount does not come with a smart handset of the kind provided by Celestron or Sky-watcher. So I'll modify my question to: can the GoTo functions be performed successfully via your tablet or laptop if you don't involve APT etc (which are not needed to make a Celestron or Sky-watcher mount work)?

BTW, to successfully restart from PARK with a Sky-watcher mount, one has to perform the following: mechanical polar align, star align, select PARK, & Park to Home Position in utilities (mount moves to home position, announces parameters saved, requests power off.) On power on, it requests: Start from PARK yes/no?   I expect that your mount will have to do the same (though not with the same software or technical terms.)

I installed APT on a laptop but have not done more than set it up as I found that Sharpcap 4 performed all the functions I really wanted.

A lot of people are confused by the Sky-watcher alignment system, which assumes a Home position pointing at the NCP and will slew to the general direction of sundry objects (algnment stars) before a star alignment is performed, using only the home position and the time/date.

 

[JayMS]

On 05/07/2022 at 18:27, Cosmic Geoff said:

Having looked up the specs, I see what you mean. Despite the eye-watering price, the mount does not come with a smart handset of the kind provided by Celestron or Sky-watcher. So I'll modify my question to: can the GoTo functions be performed successfully via your tablet or laptop if you don't involve APT etc (which are not needed to make a Celestron or Sky-watcher mount work)?

BTW, to successfully restart from PARK with a Sky-watcher mount, one has to perform the following: mechanical polar align, star align, select PARK, & Park to Home Position in utilities (mount moves to home position, announces parameters saved, requests power off.) On power on, it requests: Start from PARK yes/no?   I expect that your mount will have to do the same (though not with the same software or technical terms.)

I installed APT on a laptop but have not done more than set it up as I found that Sharpcap 4 performed all the functions I really wanted.

A lot of people are confused by the Sky-watcher alignment system, which assumes a Home position pointing at the NCP and will slew to the general direction of sundry objects (algnment stars) before a star alignment is performed, using only the home position and the time/date.

 

To perform GoTo function this mount need a computerized application like Synscan of Sky-watcher, while it can be SkyX, AsiAir, APT etc. where APT has more functions like Photography, Plate Solving etc. Thanks.

Edited July 6, 2022 by JayMS

[Cosmic Geoff]

3 hours ago, JayMS said:

To perform GoTo function this mount need a computerized application like Synscan of Sky-watcher, while it can be SkyX, AsiAir, APT etc. where APT has more functions like Photography, Plate Solving etc. Thanks.

Quite.  You need to find out which piece of software is causing the problem.  I looked through the APT online help and there is a lot about cameras and no mention of e.g. a two-star GoTo align.  So if your GoTo is going wrong, you should be checking that your GoTo app is performing properly, and if it is, then you need to look at APT or the integration of APT with the GoTo app.

[JayMS]

22 hours ago, Cosmic Geoff said:

Quite.  You need to find out which piece of software is causing the problem.  I looked through the APT online help and there is a lot about cameras and no mention of e.g. a two-star GoTo align.  So if your GoTo is going wrong, you should be checking that your GoTo app is performing properly, and if it is, then you need to look at APT or the integration of APT with the GoTo app.

I see. I will check one by one to narrow the scope. Thanks.

[JayMS]

Here is the summary on my issue.
1. Goto deviation on APT was settled down by 3 stars alignment and SYNC process.
2. Goto deviation on Stellarium came from wrong mount set up of Telescope control plug-in in Stellarium, in addition to Stellariumscope Mount property and Stellarium Location infomation.
    This was solved by following procedure.
    - Click on the Telescope icon in the pop up try at the bottom of the Stellarium window.
    - A small window will open. Click on Configure Telescope.
    - Another window will open, next to the Connect button there are 3 other buttons. The middle button "Add new Telescope" select ASCOM.
      (My previous selection was Stellarium, serial port option.)
    - Next go to the wrench button to set up the scope, the ASCOM chooser is near the bottom of this page. From there I can find Temma driver.
 Thanks.