On Mon, Jan 8, 2024 at 03:13 PM, @VictoryPete wrote:

Do you have a link to that App, I would like to check it out.

I use one called Polar Align - if you type that in to the Google Apps tore it comes up with an icon that looks like the Dipper.? Gold stars on a blue background

Brian

Thanks very much for your detailed response! I’ll have to give some thought to whether to keep all parts in the same case or separate them. For me the total weight will be the thing that drives my decision.?

On Mon, Jan 8, 2024 at 11:47 AM, Chip Louie wrote:

Hi John,

If you are going to image and going have a computer with you it is hard to beat using a PoleMaster, SharpCap etc. to polar align your mount.?

If you are looking for a computer free way to get polar aligned for visual use the Losmandy polar scope is quite accurate and no more difficult to use than lower accuracy polar scopes. The Losmandy polar scope is not designed to be easy to use so much as accurate and requires some effort to setup.

The Losmandy polar scope reticle is not your typical plastic commodity reticle with silkscreened or embossed lines. It is a precision etched glass reticle designed to be used in a precision optical instrument. It requires accurate alignment in the polar scope and correct installation in a Losmandy mount. If you do it right you are rewarded with a polar scope that can give you excellent polar alignment.

There is are two reason to the Losmandy polar scope reticle lacks the so called easy to use large circles on it, accuracy and precision. Commodity polar scopes lack the precision to use finer positioning marks so a large circle is the best they can do. I can assure you the Losmandy polar scope is very capable of accurate visual polar alignment if you do your part.?
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Chip Louie Chief Daydreamer Imagination Hardware

? ?Astrospheric Weather Forecast - South Pasadena, CA?

The EQ6-R Pro polar scope is very accurate after it is calibrated and has a precision etched graduated 12-hour circle. The polar scope is accessible from the App and allows you to adjust the brightness and access the current polar time. I find it does a much better job than the Losmandy polar scope. I have used them side by side. The optional light module for the Losmandy polar scope is difficult to use, both turning it on/off and adjusting brightness. There are pros and cons to all of this equipment and in this regard the EQ6-R "Pro" is just that.

On Mon, Jan 8, 2024 at 11:10 AM, John Kmetz wrote:

The app PS Align for smart phones has the reticle design for the Losmandy polar scope and for most other manufacturers as well. However, I’ve never used one. With PoleMaster and SharpCap being so easy to use, the polar scopes are really things from the past now. However, they are still avaible for though who choose to go that way.

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John

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Do you have a link to that App, I would like to check it out.

I actually find the Losmandy polar scope pretty easy to use.? I have set up using that and the phone app to help me orient the reticle.? Typically can get within single digit arc-minutes of accuracy with that.? I know this as I check the PA with the ASI Air before imaging.??

When I set up the last time on my permanent pier, I got really lucky and was already at 2 arc-minutes.? I indulged and got to 30arc-seconds using the app.? ?You can go online and find calculators that tell you how long you can imaged based on your scope, camera and where in the sky your target it for any given polar alignment accuracy.? You'll see it does not need to be as close as you think to achieve even 5 minute subs.? ?I think at 30 arc-sec I can go for 10s of minutes over most of the sky - way overkill.?

Only thing I really wish the polar scope had was a right angle viewfinder.?


Brian

On Sun, Jan 7, 2024 at 04:10 AM, John Natale wrote:

I am considering getting the illuminated polar scope that is an option for the G11G. Does anyone know what the reticle looks like? I am hoping it is just a simple 360 degree circle, so I can use the "Polar Scope Align Pro" app, and just put Polaris in the spot where the app tells me to during alignment. I have seen reticles with the big dipper, Cassiopeia etc and am wondering what this one looks like.

Also, if I get this polar scope, are there installation instructions, or does it come installed already? I'm wondering if there is some sort of calibrartion/adjustment I will need to do (similar to my EQ6 mount's polar scope). It seems like it would need to be installed precisely in the right spot and at the right angle for it to work.

Hi John,

If you are going to image and going have a computer with you it is hard to beat using a PoleMaster, SharpCap etc. to polar align your mount.?

If you are looking for a computer free way to get polar aligned for visual use the Losmandy polar scope is quite accurate and no more difficult to use than lower accuracy polar scopes. The Losmandy polar scope is not designed to be easy to use so much as accurate and requires some effort to setup.

The Losmandy polar scope reticle is not your typical plastic commodity reticle with silkscreened or embossed lines. It is a precision etched glass reticle designed to be used in a precision optical instrument. It requires accurate alignment in the polar scope and correct installation in a Losmandy mount. If you do it right you are rewarded with a polar scope that can give you excellent polar alignment.

There is are two reason to the Losmandy polar scope reticle lacks the so called easy to use large circles on it, accuracy and precision. Commodity polar scopes lack the precision to use finer positioning marks so a large circle is the best they can do. I can assure you the Losmandy polar scope is very capable of accurate visual polar alignment if you do your part.?
?
--

Chip Louie Chief Daydreamer Imagination Hardware?

? ?Astrospheric Weather Forecast - South Pasadena, CA?

On Sun, Jan 7, 2024 at 04:15 AM, John Natale wrote:

What is the best option for a carrying case for the G11G? Is there one commercially available, and if so, can someone post a link to it? I have heard that the RA axis needs to be disassembled from the alt section for storage, and the two parts put in different cases. Is that correct? Does that work well, or is there another storage method that you recommend (i.e., buying a pelican case with foam and storing the whole thing as one unit)???

If you separate the RA and DEC but only use one case you run the risk of damaging them. Keep the mount halves assembled and pad out or build a simple plywood frame and staple indoor outdoor carpet to it to restrict mount movement inside the hard case in the upright position when the case is in the upright and rolling. Leave the clutches fully loose to minimize impacts on the OPW bearing blocks. The OPW's bearing blocks can be pushed out of adjustment easily as the fasteners are small and the mount is heavy, add a small bit of impact and the fasteners are easily pushed out of adjustment.?

My best suggestion is to buy a large rolling Pelican case to transport and store the mount in. I use a Pelican 1610 rolling case and while heavy it is extremely strong and protective. The Pelican 1610 is large and allows me to put a complete G11G inside with more than enough room for everything needed to support the mount including the counter weight shaft, counter weights, Gemini-2 system, cables extension cord mount tool kit and spare batteries and other bits. It is very heavy when fully loaded this way so when going solo I pack the counterweights and counterweight shaft separately in a small DIY carrier or Pelican 1510 roller to allow me to lift the mount case myself.?
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You can also separate the RA and DEC but IME that just creates yet another box to keep track of and another way to lose mount parts. I bought the Pelican cases used and only have a couple hundred dollars in the cases I use for the G11.?

I have also recently entertained the idea of buying the heavy duty Milwaukee rolling tool carrier and additional add-on cases for accessories but the red color is hideous. I guess a can of spray paint goes a long way. These cases are modular and offer flexibility for a perfect fit and have large wheels for uneven ground. Not as protective but for car transport perfectly good. The smaller case modularity allows breaking down the G11 mount head and keeping the parts locked together in the wheeled stack. You have to buy several cases to make it happen and it will not be cheap, you'll be into it for about $700 or more for the minimum required three cases. If you go this route but other than the color and the cost this is a.perfect fit for a G11 mount.?



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Chip Louie Chief Daydreamer Imagination Hardware?

? ?Astrospheric Weather Forecast - South Pasadena, CA?

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Losmandy G11G2 on pier; refurbed Losmandy G11 with OnStep controller; SkyShed design roll-off observatory; ZWO ASI2600MM-P; ZWO ASI071MC; Sky-Watcher Esprit 100 ED with field flattener; Celestron C925 Edge HD with 0.7XFR, William Optics Zenithstar 61 APO; PHD2, Sequence Generator Pro and PixInsight user

Thanks - I use sharpcap's electronic polar alignment, but like having a back-up polar scope just in case. Too bad the G11G's polar scope doesn't have the graduated circle option.?

On Sun, Jan 7, 2024 at 07:10 AM, John Natale wrote:

I am considering getting the illuminated polar scope that is an option for the G11G. Does anyone know what the reticle looks like? I am hoping it is just a simple 360 degree circle, so I can use the "Polar Scope Align Pro" app, and just put Polaris in the spot where the app tells me to during alignment. I have seen reticles with the big dipper, Cassiopeia etc and am wondering what this one looks like.

Also, if I get this polar scope, are there installation instructions, or does it come installed already? I'm wondering if there is some sort of calibrartion/adjustment I will need to do (similar to my EQ6 mount's polar scope). It seems like it would need to be installed precisely in the right spot and at the right angle for it to work.

?Hi John
? I have a G11G with all the options including the polar scope. It is disappointing compared to my EQ6-R's polar scope which I love. There is no graduated circle. Just star patterns where you have to insert the stars, there are no accurate circles to center the star in, just a gap between some lines. I do not use it anymore. I have the Ipolar camera and the PoleMaster cameras.

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When I bought my G11G I bought the 2 cases for the 2 parts of the G11 if you get the RA extension. It was cheaply made plastic. I returned it when I went to NEAF. It is not on their website anymore, rightly so. The case for the heavy duty tripod is a good case though, it is an SKB. I am still looking for mount case options myself. I have bought cases from this company, and I plan on having them make me some more.

Hi John,
? ?Considering all the responses and that I am late to the party; I think you have a lot of useful information. Actually, I may be able to learn something too.

What is the best option for a carrying case for the G11G? Is there one commercially available, and if so, can someone post a link to it? I have heard that the RA axis needs to be disassembled from the alt section for storage, and the two parts put in different cases. Is that correct? Does that work well, or is there another storage method that you recommend (i.e., buying a pelican case with foam and storing the whole thing as one unit)???

I am considering getting the illuminated polar scope that is an option for the G11G. Does anyone know what the reticle looks like? I am hoping it is just a simple 360 degree circle, so I can use the "Polar Scope Align Pro" app, and just put Polaris in the spot where the app tells me to during alignment. I have seen reticles with the big dipper, Cassiopeia etc and am wondering what this one looks like.

Also, if I get this polar scope, are there installation instructions, or does it come installed already? I'm wondering if there is some sort of calibrartion/adjustment I will need to do (similar to my EQ6 mount's polar scope). It seems like it would need to be installed precisely in the right spot and at the right angle for it to work.

Thanks everyone- I really appreciate the info.

Thanks again Ken-? the screen shot really helps. From the picture it looks like I will need to use a baud rate of 9600 with the G11G. My Skywatcher EQ6 mount/EQMOD uses a baud rate of 115200. Hopefully in Sharpcap I can just input all the data for the G11G, and in the future when I choose that mount its settings will automatically come up. That way I won't have to reprogram sharpcap every time I change a mount.

I have been trying to find out the sub-second dynamics of my G11S with OnStep for which a guide error log is sampling too slow.? The only way I could think of was to create star trails using the hand controller and analyze them.? Speed variations result in variations of light intensity.? This can easily be inverted and integrated to retrieve the deviations from the nominal trajectory.? Its power spectrum then tells the oscillations of which some may be attributed to the stepper motor.?

For a focal length of 755 mm (ES127CF+FF) and a pixel size of 3.8 mu (ASI2600) at nominal RA tracking speed (relative to the sky) the stars move at 14.6 pixels/s so we can analyze up to about 7 Hz.? I took some star trails at various speeds, rotated them vertically in Gimp then imported them in Scilab for analysis.? I used an order 10 polynomial trend removal to account for incident angle, dust motes and other low frequent disturbances, and the median for background removal.? The DEC position is done by a weighted average of pixel values.? This is pretty crude in some ways, but I don't think it is complete nonsense.

The RA 1x relative speed is shown below.? The 700x100 pixel image on the left is the star trail (DEC is horizontal, RA vertical).? The center column has the DEC (X) and RA (Y) errors relative to the nominal trajectory.? The RA plot also shows the 10-th order polynomial trend-removed version.? Their power spectra are to the right.? DEC shows errors tapering down at 1 Hz, RA tapers down at 0.5 Hz.? Since RA is moving at 2x tracking speed, maybe this translates to errors up to 0.25 Hz at tracking speed, if it is due to the stepper motor.? Take it FWIW.

About the number of microsteps, at 64 microsteps my Nema17 micro-steps at 107 Hz.? I don't know if it makes a lot of difference with 32 microsteps at 53 Hz or 16 microsteps at 27 Hz.? The mechanical telescope system limits the bandwidth quite a bit, so any errors above 8 Hz or so get smoothed out quite a bit.?

I am interested in stepper motor related errors, which is why I did this.? Based on the above (if it can be believed), the highest frequency peak at tracking speed is below 0.25 Hz, and the magnitude looks minor compared to the rest.? Just my 2 cents.