Hi Doc,

I find it valuable to do these steps if my pointing goes haywire.??

I am using a Gemini 1, not a Gemini 2.? They differ in hardware, but I'm not aware of any difference between the two in software algorithms.??

So try these steps to diagnose what's going on.

(I use Gemini.net to more easily get to internal pointing model values.? You get that and basic ASCOM software from the ASCOM website.)

1. Using the Gemink.net Advanced window, download the internal parameters ("Read from Gemini".) Write down the existing pointing model parameter values.? I think there are about 9 of these, and they are explained in the Gemini manual.? ?Later, you will? compare the values to those of a good model.??

2. Store the existing pointing model in a file, and name that file "Nov 12 2017 bad pointing" or something like that.??

3. In Gemini.net, on the Advanced window,? uncheck the tick box "Synch performs additional Align ". Also inchecjk the box "PC sends to Gemini on connect" to make sure your PC, that may have bad values in its default file, does not send those to the handset.

4. Exit Gemini.net (software disconnect the Gemini from the PC...the cable can still be there.)

5. From the handset, perform a Cold Boot.? This sets all internal model values to zero.

6. Reconnect Gemini to the PC.? Use Gemini.net to Read the Mount values.? Ensure they are all zero still.? Also look at the Latitude, Longitude, Elevation, UTC date and time.? (There is a tickbox for having Gemini.net send the correct PC known date and time to the Gemini when it connects.? I do use that. )?

7. Start a sky chart on the PC that links to Gemini.net.? For that, I use both Stellarium-scope? (from Dragon-Welch computing website I think is ) and the sky chart itself Stellarium from? Stellarium.org.? ?You run Stellarium first to set its location to your site, then Save configuration, then exit.? Second, start Stellarium-scope, then select mount Gemini.net, then start Stellarium (a button on Stellarium-scope can do that).? Your Stellarium should show "scope" pointed at Polaris, if you are in positive latitude.? (You can minimize the Stellarium-scope window...just don't kill the program as it nicely links Stellarium and the Gemini.net together.? )

8. From the handset,? use Align Telescope to go to a bright star in its list.? Sometimes, this initial point is accurate, and sometimes, for unknown reason, it will be way off.??

(I never know if this is due to old Daylight savings time change dates internal to the Gemini1 code, or why this happens... but it does even for a cold boot.?

It's the weirdest thing because the mount correctly knows CWD...and time and location...how can it be so far far off in 1st star point?! )

9. When you have centered your first Alignment star, complete handset alignment pressing the buttons that requires.?

10. Look at the Model parameters using Gemini.net.? ?They will all still be zero.? What changed?? The settings for RA and DEC offset encoder counts.??

11. Look at the skychart.? It should show the "scope" right atop the star you aligned to.

12. Back to Gemini.net, advanced page.? Now check the tick box for "Synch performs additional Align".? That allows the Sky chart software to not only Synch the existing (all zero) model, but allows Gemini to calculate new parameter values.? ?

13. Back to the Sky chart.? Use your mouse to select a new star... (important!:) on the same side of the meridian as the first star.? (Press the spacebar to center and track that star on Stellarium.? ?) That means keep the 2nd ( and 3rd ) stars East of the meridian if the 1st star was East.? Or stars 2 and 3 must be West if the first star was West.? Use the (Control-1 in Stellarium) issue a goto from the sky chart to move the scope, then center the star on your scope with your handset.? Then on the sky chart do a Synch (Control-3 from Stellarium). Do that again for a 3rd star also same side of meridian as 1st star.

11. Now use Gemini.net "advanced" page,? Read from Gemini, and look at the model pointing parameters again.? You should see a few non-zero values.? You can save that data in a file with some name..."Model with 3 stars Nov 12 2017" etc.

12. Now use the sky chart to pick 3 stars on the opposite side of meridian.? Synch (and "Synch performs additional Align" is checked in Gemini.net) and Align to those from the sky chart.? ?Download and look at the parameter list and see more values change.??

14. At this point,? I stop and save the model as full model for the? date.? ?Your system should accurately point to new objects around the sky.? I also Un-check the box "Synch performs additional Align " because I don't want added star's data to somehow mess up the calculations (which are a black- box to me).??

15.? Now examine the model values.? ?How do your original "bad" model values compare?

Let us know what you find....?

I hope all these steps get you to a good and repeatable solution, and more enjoyment of your system.

-

Michael Herman?

On Nov 11, 2017 6:11 PM, "lfbqtuqvokrxwkk24m2de6zj23io2kfpm5qcqt2w@... [Losmandy_users]" <Losmandy_users@yahoogroups.com> wrote:

?

Have had my G11 for about 2 years and have had pointing problems since about first 8 months in. Have had paddle and control box rehabbed twice and now both are undergoing a full reworking. I'm sure Losmandy will rehab my units appropriately but my questions are not about the fixes. I would like advice from the group on what to look for in pointing problems and what might go into correcting them. I understand it's a complex system but is there a check list of possible problems that I can look to addressing if my system encounters further issues. I have researched the web as much as I can and read the info on the Gemini 2 site but would like some guidance from the members on this as I have this feeling I'm not doing all I can to correct the problems. I have a TAK130 sitting on the G11 mount and tripod and all are in excellent operating order. Thanks, Doc

?

There s/b a washer (race) touching each side of the thrust bearing. Are you certain it is not just stuck to the aluminum bearing housing??

-Jeff