Topics

Tracking going wrong #iEXOS-100 #TECHNICAL #ExploreStars #astrophotography #windows10


Bob Trepiccione
 

Hi Jerry,

I seem to recall hearing that in one of the YouTube live vids recently...

Would the motor still run, but just not have enough oomph to turn the larger gears?



Sent from my T-Mobile 4G LTE Device


-------- Original message --------
From: Jerry Hubbell - Explore Scientific VP Engineering <jrh@...>
Date: 7/14/20 4:21 PM (GMT-05:00)
To: MAIN@ESPMC-Eight.groups.io
Subject: Re: [ESPMC-Eight] Tracking going wrong #alignment #astrophotography #ExploreStars #iexos-100 #TECHNICAL #Windows10

On Tue, Jul 14, 2020 at 01:35 PM, prmailers wrote:
Maybe Jerry or Wes can shed some light on this...
If the voltage drops below around 10.5 Vdc then the motors will not provide enough torque to drive the mount and it will start to stall/ratchet.
 
--
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


Mark Slade Remote Observatory (MSRO) IAU MPC W54 Equipment
Wilderness, VA
Mounts
: ES PMC-Eight G11 + Telescope Drive Master (TDM)
Scopes: ES 165 FPL-53 ED APO CF, ES 102 FCD100 ED APO CF
Cameras:  QHY174M-GPS + FW, QHY163C
Misc: 3-inch 0.7x Focal Reducer Field Flattener, Filters: Luminance,
Red, V-band Photometric, Diffuser, 200 lpmm Spectral Grating

Software: MaxIm DL 6, Cartes du Ciel, Astrometrica, AstroImageJ, AutoStakkert!


Jerry Hubbell - Explore Scientific VP Engineering
 

On Tue, Jul 14, 2020 at 01:35 PM, prmailers wrote:
Maybe Jerry or Wes can shed some light on this...
If the voltage drops below around 10.5 Vdc then the motors will not provide enough torque to drive the mount and it will start to stall/ratchet.
 
--
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


Mark Slade Remote Observatory (MSRO) IAU MPC W54 Equipment
Wilderness, VA
Mounts
: ES PMC-Eight G11 + Telescope Drive Master (TDM)
Scopes: ES 165 FPL-53 ED APO CF, ES 102 FCD100 ED APO CF
Cameras:  QHY174M-GPS + FW, QHY163C
Misc: 3-inch 0.7x Focal Reducer Field Flattener, Filters: Luminance,
Red, V-band Photometric, Diffuser, 200 lpmm Spectral Grating

Software: MaxIm DL 6, Cartes du Ciel, Astrometrica, AstroImageJ, AutoStakkert!


Bob Trepiccione
 

Hi Koen,

Have you checked to make sure your power source is supplying enough voltage?

I was experimenting with my mount last night and thought it was connected and appeared to be operating correctly (I could see the RA spindle turning) I could not detect any physical movement of the mount.

Fast forward to this morning after recharging my power source (rockpals 330w solar "generator") the mount is operating properly.

Might just be a coincidence, but the state of charge was pretty low last night, around 20% maybe, and I know that the 12v DC output on the rockpals is not regulated so the voltage was probably well below 12v.

Maybe Jerry or Wes can shed some light on this...

Hope ya get it worked out!


Wes Mcdonald
 

Koen 

Well you will remain limited in terms of your exposure times until you do go to guiding.  The iexos has more periodic error than the exos 2 in theory but neither can be used for long exposures without guiding.  

I must say though that at 200mm being limited to less than 13 seconds seems extreme.

Maybe you experienced dec backlash after you turned the mount south.  Try deliberately biasing the dec axis so that when the scope points to the southeast the scope has no tendency to swing across the dec backlash.  Heavy camera end on the telescope is what you need.  Try that.

One day though you will need to guide.   But you should be ok with shirt exposures at 200 mm I would think.

Have you adjusted your backlash?

Wes

--
Wes, Southport NC
EXos2-GT PMC-8, iExos 100
ES ED 127, 10" LX200GPS+wedge, Astro-Tech 8" Newt, ETX-90, 60mm no-name guide scope ~ 260mm FL
Polemaster, Orion ST-80 and SAG, ZWO 290MM, D5300 astro modified
Nina, Bootcamped Mac Mini control computer, RDP to iMAC
110 amp hour lead acid deep discharge battery for field power
Electrical Engineer, Retired


Koen M.
 

Hi Wes,

So what you are saying is that it would be best that  put some autoguide on it?
I am technically very incompetent :p so i have no idea how that would work to set up (hell i still dont understand that ASCOM stuff :p )


Wes Mcdonald
 

Koen 

One thing to remember is that tracking imperfections due to period of error are far less looking near north.  This is because ra errors do not stats very much on the camera focal plane looking north.  But when you look south things fall apart rapidly.  So my guess is that you have found the limit of unguided images at 200 mm looking south for your iexos.  

That’s just how it works.

Wes 

--
Wes, Southport NC
EXos2-GT PMC-8, iExos 100
ES ED 127, 10" LX200GPS+wedge, Astro-Tech 8" Newt, ETX-90, 60mm no-name guide scope ~ 260mm FL
Polemaster, Orion ST-80 and SAG, ZWO 290MM, D5300 astro modified
Nina, Bootcamped Mac Mini control computer, RDP to iMAC
110 amp hour lead acid deep discharge battery for field power
Electrical Engineer, Retired


Jerry Hubbell - Explore Scientific VP Engineering
 

Hi Koen,

This problem is not related to a difference between tracking a star and a planet as there is no difference. The main rate is sidereal rate based on the rotation of the earth. Planets just don't move that quickly in the sky from night to night, let alone from minute to minute. The issue could be a loose clutch getting loser when slewed back and forth, or something else mechanical.

--
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


Mark Slade Remote Observatory (MSRO) IAU MPC W54 Equipment
Wilderness, VA
Mounts
: ES PMC-Eight G11 + Telescope Drive Master (TDM)
Scopes: ES 165 FPL-53 ED APO CF, ES 102 FCD100 ED APO CF
Cameras:  QHY174M-GPS + FW, QHY163C
Misc: 3-inch 0.7x Focal Reducer Field Flattener, Filters: Luminance,
Red, V-band Photometric, Diffuser, 200 lpmm Spectral Grating

Software: MaxIm DL 6, Cartes du Ciel, Astrometrica, AstroImageJ, AutoStakkert!


Bob Trepiccione
 

I experience this same issue as well, also using stellarium (finally got it working properly, thank you Wes - your appearance on the YouTube live show the other day...)

Is there a way to change the tracking type (lunar, solar, sidereal...) I don't see it anywhere.  Maybe in the ascom setup?



Sent from my T-Mobile 4G LTE Device


-------- Original message --------
From: Tim Huseby <Photographybytjh@...>
Date: 7/13/20 2:43 PM (GMT-05:00)
To: MAIN@ESPMC-Eight.groups.io
Subject: Re: [ESPMC-Eight] Tracking going wrong #alignment #astrophotography #ExploreStars #iexos-100 #TECHNICAL #Windows10

Koen,

     That is interesting, I use Stellarium, I don’t know the explore stars app operation. Could it be backlash (play in the gears) when after it does the meridian flip if you going east to west.
--
Tim
Las Vegas
Just starting in this Hobby, I have been doing wildlife and landscape photography. 
Mounts
Exos2-gt  PMC-8, Celestron Alt/Azimuth 

Scopes/Lenses:
Celestron SLT 130, Olympus 7-14,12-40,40-150 Pro and a Canon FD 500L

Cameras: 
Olymous om-d E-M1 Mkii,


Tim Huseby
 

Koen,

     That is interesting, I use Stellarium, I don’t know the explore stars app operation. Could it be backlash (play in the gears) when after it does the meridian flip if you going east to west.
--
Tim
Las Vegas
Just starting in this Hobby, I have been doing wildlife and landscape photography. 
Mounts
Exos2-gt  PMC-8, Celestron Alt/Azimuth 

Scopes/Lenses:
Celestron SLT 130, Olympus 7-14,12-40,40-150 Pro and a Canon FD 500L

Cameras: 
Olymous om-d E-M1 Mkii,


Koen M.
 

and also when i slew to Sadira it also gives trails and not the round stars so i dont think it is because of rotation and orbit of Jupiter


Koen M.
 

Well i used the thing in ExploreStars to slew to jupiter, if what you say is correct one should think the tracking rate would be set up as it should in that program, no?


Tim Huseby
 
Edited

Koen,

      I could be wrong here as I am new to tracking Astro photography. I believe that tracking a planet would need to be at a different tracking rate/speed as it is moving in an orbit plus rotation of the earth. To me it sounds like your star photos are really sharp which lead me to this idea. Also longer focal lengths un guided can be difficult.
--
Tim
Las Vegas
Just starting in this Hobby, I have been doing wildlife and landscape photography. 
Mounts
Exos2-gt  PMC-8, Celestron Alt/Azimuth 

Scopes/Lenses:
Celestron SLT 130, Olympus 7-14,12-40,40-150 Pro and a Canon FD 500L

Cameras: 
Olymous om-d E-M1 Mkii,


Koen M.
 

A few days ago i finally had some time to go out again with the iEXOS100
I set up my mount, polar align it.
I let the camera slew to Dubeh and it tracks the way it should be. (see pic Dubhe.jpg) 
this was located North to North-west from my position

Then i let it slew to vAnd, and it goes as it should be (see pic vAnd.jpg)
This was North-east from my position

From pointing to vAnd i let it slew to Jupiter which is South-East to south from my position.
I take the same testpicture i did with the other 2 and when i look at the picture, Jupiter and its moons are not tracked but they are lines you would expect when you use a non tracking mount (startrails, see jupfail.jpg


All 3 pictures are taken with f6.3 at 13seconds shutterspeed and 200mm




)

This is not the first time i have this problem, it looks like everything i point at from North to West fails and everything from West to nord goes as it should.