Re: Needle bearings and axial play, is this a significant performance problem and how difficult is it to fix?
Here is may latest frequency plot from last night.? 125:1 gearbox. No PEC. Old thrust bearings.
In the first attached image we see the movement of the worm over almost 4 hrs.?
In the second image we see the raw frequency response. The p-p of the 80s bearing error is down massively to 1.2 arc-sec, from an earlier posting. I changed over to using a single pressure washer that compresses the ball bearings. The 240s error p-p is 2.6 arc-sec, and the 2600s error is a massive 5.8 arc-sec. I've not see this error so well defined before on shorter guiding runs. I believe this error is due to the roller bearings (either thrust or the needle bearings). I still have my original Losmandy thrust bearings in place, but will be changing over to the McMaster-Carr one this weekend.
The third? image shows the impact of guiding. The 2600s error is gone. The 80s error is now p-p 0.4 arc-sec, and the 240s error is arc-sec 0.3 arc-sec.?
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Re: Needle bearings and axial play, is this a significant performance problem and how difficult is it to fix?
On Tue, Jul 20, 2021 at 10:26 PM, alan137 wrote:
How does one get to the thrust bearings?
What's the source and part number for the encoders?
What's the maximum slew rate with the 1024 encoders?
Thrust Bearings:? McMaster-Car? Needle Roller Trust Bearing for 1-1/4" shaft, 1 -15/16" OD part number 5909K38 McMaster-Car? Needle Roller Trust Bearing for 3" shaft, 3 3/4"" OD part number 5909K28 Optical Encoders: US Digital,? call sales department to order, Part number E2-1024-125-NE-D-D-B Since the gear boxes remain at 25:1 the slew rate ought to be the same. US same values.? Peter
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Re: Meridian Flips and NINA
Peter i'm going to open a ticket with your email address
We need more specifics here, i'm unable to reproduce based on what you sent
look for direct email
Brian
On Thu, Jul 22, 2021 at 09:14 AM, Brian Valente wrote:
i was hoping to see this demonstration on the hand controller - I'm still not clear if you see this on the gemini by itself? without hooking up an external application.
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Brian,
As I said this same thing happens using the hand controller. The scope is is this position per the image for this area of the sky in the video. It's not easy to make a video out in a field, in the sun looking at green digits that appear already in the panel to the right of the video, and therefore some what pointless.??
-- Brian?
Brian Valente portfolio
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Re: Meridian Flips and NINA
On Thu, Jul 22, 2021 at 09:14 AM, Brian Valente wrote:
i was hoping to see this demonstration on the hand controller - I'm still not clear if you see this on the gemini by itself? without hooking up an external application.
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Brian, As I said this same thing happens using the hand controller. The scope is is this position per the image for this area of the sky in the video. It's not easy to make a video out in a field, in the sun looking at green digits that appear already in the panel to the right of the video, and therefore some what pointless.??
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Re: Meridian Flips and NINA
Hi Peter
i was hoping to see this demonstration on the hand controller - I'm still not clear if you see this on the gemini by itself? without hooking up an external application.
On Thu, Jul 22, 2021 at 08:27 AM, Brian Valente wrote:
Peter most importantly is what steps can someone take to reproduce it
Brian,
I made this 3min video of the problem occurring. This was after doing a hand controller reset and entering all my data anew. As you will see, as the bulls eye moves from the CDW position and it gets close to the target it winks out a reappears in the lower left corner of the screen. I was able to move to bullseye "scope" to another target in this "dead zone", and then out of the dead zone where the bulls eye reappears.?
I think this makes the whole problem clear for folks here so that they can do their own tests. I first noticed this problem in January during galaxy season. This was before making any changes to gearboxes etc.
I will email this link to Rene, perhaps you too could contact him.?
Peter
-- Brian?
Brian Valente portfolio
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Re: Meridian Flips and NINA
On Thu, Jul 22, 2021 at 08:27 AM, Brian Valente wrote:
Peter most importantly is what steps can someone take to reproduce it
Brian, I made this 3min video of the problem occurring. This was after doing a hand controller reset and entering all my data anew. As you will see, as the bulls eye moves from the CDW position and it gets close to the target it winks out a reappears in the lower left corner of the screen. I was able to move to bullseye "scope" to another target in this "dead zone", and then out of the dead zone where the bulls eye reappears.? I think this makes the whole problem clear for folks here so that they can do their own tests. I first noticed this problem in January during galaxy season. This was before making any changes to gearboxes etc. I will email this link to Rene, perhaps you too could contact him.? Peter
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Re: Meridian Flips and NINA
Peter most importantly is what steps can someone take to reproduce it
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
-- Brian?
Brian Valente portfolio
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Re: Meridian Flips and NINA
>>>
I would encourage folks to do their own tests. I can video the problem if that would help.
yes please
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
-- Brian?
Brian Valente portfolio
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Re: Meridian Flips and NINA
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
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Re: Meridian Flips and NINA
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":
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Re: Meridian Flips and NINA
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.
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Re: Meridian Flips and NINA
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
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Re: Meridian Flips and NINA
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.
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Re: Meridian Flips and NINA
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.
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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?
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Re: Meridian Flips and NINA
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?
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Re: Meridian Flips and NINA
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
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Re: Meridian Flips and NINA
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
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Re: Meridian Flips and NINA
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?
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Re: Meridian Flips and NINA
The jump occurs when you cross over the 353 degree boundary in Az.
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Re: Meridian Flips and NINA
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.
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Paul Kanevsky