开云体育

--

--

I reset Gemini and reloaded everything. Slewed to that area of the sky and same problem, This? nothing to do with flips or NINA, but clearly there is a serious bug with the Gemini II software itself.?

All the recent tests were done strictly with the hand controller. I simply can not believe I'm the only one with the issue.? Perhaps it's because I'm going to an area of the sky others do not, or like me experienced the problem and thought is was a one off and a flip problem.

I would encourage folks to do their own tests. I can video the problem if that would help.

Peter

On Thu, Jul 22, 2021 at 10:34 AM, <pcboreland@...> wrote:

Is it possible to reset Gemini II to its factory defaults?

From Gemini HC, press "Reset HGM Defaults":


From Gemini web pages, press "RESET SRAM":

On Thu, Jul 22, 2021 at 10:34 AM, <pcboreland@...> wrote:

So it seems the problem is with the Gemini II controller and not the driver?

You said the RA coordinate jumps on the Gemini physical hand controller, so no, this has nothing to do with the driver. Again, I don't know anything about NINA meridian flips, and can't help you there. All I'm talking about is the coordinate jumping when nearing the AZ 360 degree limit.

So the problem existed well before messing with gearboxes or encoders. Is it possible to reset Gemini II to its factory defaults? I hate to do this because I'll have to reprogram everything.??

There is definitely an abrupt transition point where both the AZ and Alt axis coordinates jump. The Alt value goes from +80s to a negative value. However, in this dead zone you can still navigate to stars correctly even though the coordinates being shown are wrong.? Hence, to can navigate to a point just outside the dead zone on the target reappears on the chart. The problem with the flip if you are in this deadzone, is NINA grabs these messed up coordinate and slews to them.

So it seems the problem is with the Gemini II controller and not the driver?

Peter

On Thu, Jul 22, 2021 at 09:42 AM, <pcboreland@...> wrote:

The scope thinks it's the southern hemisphere as shown in this pic, where it? should be sayings it's in the blue zone. By rotating the Dec access pointing to the north it will again show its correct location. With Dec in this location it suddenly? decided oh I'm am in the northern hemisphere at 353 degrees Az and the target jumps to the correct location. Is this a problem with me, you or Rene?

Let me ask you, is this with your higher resolution encoders / smaller step size? That could be a problem for some internal Gemini computation. In all my years using Gemini, I've not seen the problem you're reporting.

Can't imagine how the driver can do this, especially since the Gemini HC is also showing the same coordinates. The driver displays what Gemini reports.

The scope thinks it's the southern hemisphere as shown in this pic, where it? should be sayings it's in the blue zone. By rotating the Dec access pointing to the north it will again show its correct location. With Dec in this location it suddenly? decided oh I'm am in the northern hemisphere at 353 degrees Az and the target jumps to the correct location. Is this a problem with me, you or Rene?

On Thu, Jul 22, 2021 at 06:09 AM, Paul Kanevsky wrote:

So when crossing over 353 deg in Az, RA jumps by 7 hours? Is? that while tracking or when doing a goto? Did you confirm if that happens on the physical hand controller as well as in the driver display?

Yes, that's right. Yes now using the hand controller. So the mount does this if tracking, but you can also slew Ra to the boundary transition point with the? hand controller. Driver display shows the same thing as the hand controller.

Peter

Paul,

With the scope at the eastern limit of 90 degrees, the Az value reads 346 degrees. Slewing past the boundary value of 353 degrees? the value suddenly jumps to something in the 200s.?

Peter

On Thu, Jul 22, 2021 at 08:55 AM, <pcboreland@...> wrote:

The jump occurs when you cross over the 353 degree boundary in Az.

So when crossing over 353 deg in Az, RA jumps by 7 hours? Is? that while tracking or when doing a goto? Did you confirm if that happens on the physical hand controller as well as in the driver display?

The jump occurs when you cross over the 353 degree boundary in Az.

On Thu, Jul 22, 2021 at 08:36 AM, <pcboreland@...> wrote:

I have no model. I always cold start Gemini.? This problem has existed for months with many restarts/resets. During galaxy seasons target always ended up in this part of the sky, this is when I noticed the flip was failing.?

I'm not thinking about the flip failing, but the RA coordinate jumping from 2h to 15h after a small move. Flips are performed by Gemini. ASCOM Driver just sends the command to perform one.

I have no model. I always cold start Gemini.? This problem has existed for months with many restarts/resets. During galaxy seasons target always ended up in this part of the sky, this is when I noticed the flip was failing.?

Try to clear out and reset any model that you may have in Gemini, cold start, or even fully reset Gemini to make sure.

Regards,

? ? ?-Paul

Paul,

I've found a boundary condition were my meridian flip fails. The scope stays on the west side and ends up pointing at the ground. Any thoughts by folks in the group would be appreciated. I do not know if this is a settings problem or a bug someplace??

On Wed, Jul 21, 2021 at 02:29 AM, Vishal Billa wrote:

I've finally gotten around to testing the performance of my G11G and everything wenty great except for some pretty erratic behavior in the RA axis diring guiding. I used all default settings, except for the recommended changes from the guiding assistant, and was able to get around .8" error in the DEC axis but almost 3" error in the RA axis. I'll attach links to the guide/debug log but I'm not sure what to look for when reading them; I was hoping someone here could comment on whether this looks like an issue to be solved in PHD2 settings/PEC training or if this is something going on in the mechanics of the mount.

Vishel,

It would help if you could post a few pictures of your mount (Dec and Ra worm drives. I ran an FFT on the raw data and you do have some nasty issues. There is a lot in this form on the 76s error related to the bearings, but you have a 14 arc-sec peak-to-peak 120s error. I do not know where this come from, or the large 60s error.?

Peter

A few points I'd like to add:

I think everybody should check the relative position of the worm with respect to the center of the ring gear as the starting point when looking at Dec backlash. This is true of new mount owners and certainly used mounts. We are talking about an error of just a few thou or less can cause serious issues with regard to backlash. If the worm is not ridding dead center the force needed to rotate the worm increases a lot effecting backlash and the general well being of the worm in terms of longevity. So how the take stock of the situation:

1. While the clutch is tight, remove the cover to the worm keeping it locked in place and using feeler gage establish to reference when the stack of feeler gage just starts to have a little resistance sliding under the smooth 1/2" section of the worm.

2. Remove the entire worm assemble keeping the bearing block in place, and rotating them out of the way press the worm into the ring gear with your thumb.

3. Now using the same stack of feeler gages, slide it under the same point in the worm. The resistance you felt before sliding it under the same point on the worm ought to be the same. If you can not get the gages under the worm the ring gear is too close to the base plate. You should change the top thrust bearing. The one that Michael and I used was sourced from McMaster and cost I think about $13. Its seems to be a high quality component. I would not get one from Losmandy. When I did this the high ring gear turning resistance I had before with the clutch tightened went away.??

4. If the stack of gages slide under the worm easily then the worm itself is too low. You will the have to shim under the bearing blocks. I had a set of original blocks the were black but silver underneath. The new blocks from Losmandy are differently dimensioned.? You might try a new set, else if that is what you already have, you will have to shim the bearing blocks. You can use the feeler gage to determine the thickness of the shim material. Or take one of the feelers and use that.

Peter?