Date   

Re: ES G11 / ExploreStars issues

Steve Siedentop
 

Oops...forgot to attach an image of the power box...



On Thu, May 3, 2018 at 5:40 PM Steve Siedentop <sdsiedentop@...> wrote:
Hi David -

By fresh batteries, I mean a fully charged deep cycle.  Mine was about 6 years old, so I replaced it with an AGM deep cycle today.  It’s a 60 amp hour battery, which should be enough capacity for a 5 hour imaging session.

My original power box with a group 24 lead acid battery powered a cooled DSLR, an NEQ6, an Intel Compute Stick, Moonlite focuser, a powered USB hub, and a Surface Pro for about 5 hours.

I’m going to put an ammeter in-line on the power supply to the PMC-8 to see what the real time consumption is while slewing and tracking.

I’ll post my findings as well.

-Steve

On Wed, May 2, 2018 at 4:48 AM David Pickett yahoo@... [ESPMC-Eight] <ESPMC-Eight@...> wrote:

At 16:47 01-05-18, Steve Siedentop sdsiedentop@... [ESPMC-Eight] wrote:

>As Jerry stated, the RA Direction and DEC
>Direction switches in the preferences pane
>change the direction of each axis to accommodate

>the mount pointing south. I had these turned

>on, which may very well have been what was causing the drift.

Unless you are doing photography, or are using a
large magnification, it should be fairly easy to
keep objects in the field of view even if the motors stop running.



>My next outing will include fresh batteries and
>a standard configuration in the app.

Fresh batteries sound like an expensive long term
proposition. I am using a YUASA NP7-12 7.0 Ah
rechargable lead acid battery. I am also making
up a 12-19 volt convertor to keep my laptop
running from the same source. Time will tell
whether this has enough capacity for the job. Watch this space... :)

Best,

David


Re: ES G11 / ExploreStars issues

Steve Siedentop
 

Hi David -

By fresh batteries, I mean a fully charged deep cycle.  Mine was about 6 years old, so I replaced it with an AGM deep cycle today.  It’s a 60 amp hour battery, which should be enough capacity for a 5 hour imaging session.

My original power box with a group 24 lead acid battery powered a cooled DSLR, an NEQ6, an Intel Compute Stick, Moonlite focuser, a powered USB hub, and a Surface Pro for about 5 hours.

I’m going to put an ammeter in-line on the power supply to the PMC-8 to see what the real time consumption is while slewing and tracking.

I’ll post my findings as well.

-Steve


On Wed, May 2, 2018 at 4:48 AM David Pickett yahoo@... [ESPMC-Eight] <ESPMC-Eight@...> wrote:

At 16:47 01-05-18, Steve Siedentop sdsiedentop@... [ESPMC-Eight] wrote:

>As Jerry stated, the RA Direction and DEC
>Direction switches in the preferences pane
>change the direction of each axis to accommodate

>the mount pointing south. I had these turned

>on, which may very well have been what was causing the drift.

Unless you are doing photography, or are using a
large magnification, it should be fairly easy to
keep objects in the field of view even if the motors stop running.



>My next outing will include fresh batteries and
>a standard configuration in the app.

Fresh batteries sound like an expensive long term
proposition. I am using a YUASA NP7-12 7.0 Ah
rechargable lead acid battery. I am also making
up a 12-19 volt convertor to keep my laptop
running from the same source. Time will tell
whether this has enough capacity for the job. Watch this space... :)

Best,

David


Re: Generating Celestial Objects Files for Explore Stars

hubbell_jerry@...
 

Hi Steve,

I am going to forward your question to our ExploreStars developer who created this data structure for the database. I could tell you most of these, but I am not sure about 2 or 3 of these fields. I will let you know what he says.

Thanks

Jerry Hubbell
Director Electrical Engineering
Explore Scientific, LLC.


Generating Celestial Objects Files for Explore Stars

Steve Siedentop
 

Hi Jerry -


I'm working on putting together an application to generate files of celestial objects on demand for the Explore Stars app.  The layout of the file being parsed is generally intuitive, but I have some questions about some of the data elements.


Index:  This appears to be a primary key of sorts (incremental id).  Am I correct?

MapNum:  This correlates to the map graphic file of the same name.  Correct?

ImageNum:  This correlates to the image graphic file of the same name.  Correct?

Desig:  This is the object designation in various catalogs

group:  Not sure what the first value represents.  Am I correct in assuming that the second value is the constellation the object is in?

Common:  Common name of the object.

OType:  Object type.  What are the acceptable values for this data element?

Distance:  Distance to the object from Earth in light years

RA_S:  Right Ascension Coordinates?

DEC_S:  Declination Coordinates?

Constellation:  The constellation in which the object can be found.

AMag:  Absolute Magnitude

key:  Not sure what this is or what it maps to as a data element.  Similar in purpose to Index?

title:  The title displayed at the top of the screen.




{

"Index" : "14824",

"MapNum" : "01",

"ImageNum" : "01",

"Desig" : "24 Andromedae, Theta Andromedae, HIP 1366, SAO 53777, HD 1280, GC 334, HR 63, DM BD+37    34, TYC 2782-2251-1",

"group" : { "key" : "Andromeda" },

"Common" : "Theta Andromedae",

"OType" : "Star",

"Distance" : "93.77",

"RA_S" : 4.27289837,

"DEC_S" : 38.6816459,

"Constellation" : "Andromeda ",

"AMag" : 4.607,

"key" : 34824,

"title" : "Theta Andromedae"

},



Thanks in advance for your help!


-Steve


Re: G-11 worm issues

W. Christopher Moses
 

I was getting some odd behavior, but I'm pretty sure it was due to a flakey PoleMaster.  However, I will double check just to be sure.


Re: G-11 worm issues

W. Christopher Moses
 

Wow, that is off.


Re: G-11 worm issues

ji.theriot@...
 

Is yours doing the same thing?  If so, give Alex a call.  He is familiar with the issue at this point.


Re: G-11 worm issues

ji.theriot@...
 

This is what it looked like when I first pulled the cover.  Like I said, it was obviously binding.

Ji


Re: G-11 worm issues

W. Christopher Moses
 

I've turned mine by hand. I understand what you mean.


Re: G-11 worm issues

ji.theriot@...
 

I don’t think anyone really knows a measurement for the acceptable degree of offset. This was on my RA axis. The worm on my dec axis is also very slightly misaligned but there is no binding. When I first removed my worm cover it was very obvious that the worm was binding on the RA side. If you were to try to turn the worm by hand it would spring back to its original spot. If you kept spinning it slowly that built up torque would unload and rapidly spin the worm. It’s hard to explain but it’s very obvious if you’re having this issue and try to turn the worm by hand.


Re: G-11 worm issues

W. Christopher Moses
 

Very interesting. Thanks for sharing.
Was it on your DEC or RA?
Did Jerry or Alex say what degree of misalignment is acceptable?  I'm not even sure how to measure that.


G-11 worm issues

ji.theriot@...
 

To make a long story short even with a perfect (literally a 0.0" on my guide log) PA I couldn't get my RMS under .9" on my new G11.  Peak to peak PE was >30".  Most nights RMS was about 1.1", still better than my old EXOS-2 but no where near what I was seeing from other G11 owners.


After reading Jeremy's detailed discussion about his mount and the large PE he was experiencing, I decided to look at mine.  What I found was a coupler that was binding and unloading as it rotated.  This was, as I discovered, due to the motor shaft and worm being offset from each other. 


After lengthy discussion with Jerry and Alex from ES, they will be milling me a new motor mount that is slotted to adjust it, which should fix things, but if you are having similar issues, I advise you look at the motor/worm alignment..


Re: Worm Cover Plate Set Screws (1/8" - 40 x 3/16")

W. Christopher Moses
 

Thanks


Worm Cover Plate Set Screws (1/8" - 40 x 3/16")

Steve Siedentop
 

All - 


I managed to lose one of the set screws from the DEC worm cover.


I found a suitable replacement at Harbor Freight in their Storehouse Set Screw Assortment (1/8" - 40 x 3/16").


https://www.harborfreight.com/150-piece-set-screw-assortment-67671.html


Hope this is helpful to someone at some point.


-Steve




Re: ES G11 / ExploreStars issues

David Pickett
 

At 16:47 01-05-18, Steve Siedentop sdsiedentop@gmail.com [ESPMC-Eight] wrote:

As Jerry stated, the RA Direction and DEC
Direction switches in the preferences pane
change the direction of each axis to accommodate
the mount pointing south. I had these turned
on, which may very well have been what was causing the drift.
Unless you are doing photography, or are using a
large magnification, it should be fairly easy to
keep objects in the field of view even if the motors stop running.

My next outing will include fresh batteries and
a standard configuration in the app.
Fresh batteries sound like an expensive long term
proposition. I am using a YUASA NP7-12 7.0 Ah
rechargable lead acid battery. I am also making
up a 12-19 volt convertor to keep my laptop
running from the same source. Time will tell
whether this has enough capacity for the job. Watch this space... :)

Best,

David


Re: Guide Graphs and Impressions

W. Christopher Moses
 

Hi,
I will look in to the RA Osc number, I've never really paid much attention to it.
Thanks for the tip.

I am pulse guiding.  What are you using?


Re: Guide Graphs and Impressions

W. Christopher Moses
 

Hi,
I always try to get as close as I can to the equator and meridian but my FOV at home isn't the greatest.   The number of guide pulses in each direction is pretty close during the calibration. I did a star-test at one point, just as a sanity check, and it looked good - all sides were equal. 


Re: Guide Graphs and Impressions

W. Christopher Moses
 

Hi Sunil, Jeremy,
When I first received my PoleMaster it was out of focus. After I fixed that it worked perfectly, as far as I know, until a few nights ago - which is the first time I've used it since last winter.  I wonder if it has slipped out of focus again.  It looks ok on the screen.
Those are good tips. Thanks.
Actually, SC requires a pretty large field of view 1-5 degrees, so I was using my main camera.

Looking at the forecast, it will be a few nights before I get to test anything, but I look forward to it.


Re: ES G11 / ExploreStars issues

Steve Siedentop
 

Thanks, David.

Through a good bit of experimenting, I introduced too many variables to be able to determine the cause of the tracking issues.

As Jerry stated, the RA Direction and DEC Direction switches in the preferences pane change the direction of each axis to accommodate the mount pointing south.  I had these turned on, which may very well have been what was causing the drift.

My next outing will include fresh batteries and a standard configuration in the app.

-Steve

On Mon, Apr 30, 2018 at 1:20 PM, David Pickett yahoo@... [ESPMC-Eight] <ESPMC-Eight@...> wrote:
 

At 18:29 30-04-18, sdsiedentop@... [ESPMC-Eight] wrote:
>Questions for Jerry (or anyone else that may be able to answer):
>
>What function do the RA Direction and DEC Direction controls perform?

They are instead of steering the mount by hand;
as long as the clutches are engaged, PMC will
continue to know where the mount is pointed.

>Also, would a .33 difference in the tracking
>rate present itself visibly in the eyepiece in a
>very short period of time, or is it something
>that would present itself in a long exposure (5 minutes +)?

(0.33/53.33) x 100 = 0.62%

Since the stars move 15°/hour, or 1.25° per 5
minutes, even if your mount doesnt move for five
minutes, a star will only have moved 1.25° from
the centre of view. If the field of view of your
scope/eyepiece is greater than 2.5°, the star
will not have reached the edge of the field of
view in 5 minutes! Thus, if your mount is
tracking 0.62% slower than it should be, the star
should still be well in view after longer than 5 minutes.

David



Re: Guide Graphs and Impressions

Jeremy Parker
 

Hi Sunil,

Interesting, I'll keep an eye out for any sudden issues with mine. The atmospheric refraction is in one of the menu settings, can't remember off the top of my head. Also, the camera must be oriented correctly when using this feature (so the USB connector is pointing horizontally to the left when looking into the lens of the camera). I can see why using your main imaging camera would be most accurate for this. Maybe someday when I get a real astro cam, I will switch over to this method. In the meantime, I can get pretty good polar alignment and see no field rotation in over 8 minute exposures (longest I've tried).

Thanks,
Jeremy

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