Re: "Nudge Mount Out of Safety Limit On Slew"?
On Mon, Jun 28, 2021 at 10:56 AM Jim Waters < jimwaters@...> wrote: Where's this setting located???
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Jim W
Phoenix, AZ. USA
Losmandy GM811G, NINA 1.11, ASI2600MC Pro, Sky-Watcher Scopes
-- Brian?
Brian Valente portfolio
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Re: "Nudge Mount Out of Safety Limit On Slew"?
On Mon, Jun 28, 2021 at 01:56 PM, Jim Waters wrote:
Where's this setting located???
Setup --> Advanced Gemini Settings... --> Set Safety Limits --> Set Arbitrary Safety and Goto Limits... Look near the bottom of that window:
Regards, ? ?-Paul
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"Nudge Mount Out of Safety Limit On Slew"?
Where's this setting located???
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Jim W
Phoenix, AZ. USA
Losmandy GM811G, NINA 1.11, ASI2600MC Pro, Sky-Watcher Scopes
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Re: Yet another DIY spring loaded worm - ultra minimalist approach
Yes, the rubber is simply a shim material that provides a cushioned directional force vector (vs. the mechanics of machining in bolts with spring loading). I am not sure a picture would provide much more detail on installation.
Your concern over load due to worm friction was experienced in my first try on the DEC with a ~3/4" length section of banding. That generated a "Heavy Duty TR" error on DEC slewing. So I reduced the length to ~1/2" on each band and that cleared up the DEC duty error.?
Summer in Tucson is not only excessively warm, but comes with evening monsoon storms/clouds (not to mention fewer interesting high targets in the evening, so it is a good time of year to play with observatory h/w-s/w configurations).
So I am waiting on good weather for scope time in order to test the guiding performance and monitor the motor loads over time, etc.?
-Greg
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The following files have been uploaded to
the Files area of the [email protected] group.
By: Edward Plumer <eplumer@...>
Description:
Spreadsheet to compute compatible settings between Gemini-II and NINA v1.11 to do a meridian flip.
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Re: Meridian Flips and NINA
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Re: Meridian Flips and NINA
LOL, a tale of two Pauls , I was asking Paul Kanevsky if he knew anything about the Gemini-ASCOM support for "CanSetPierSide" and was asking Paul Borland if he would post his parameters .... Sorry about that confusion
--
Edward
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Re: Very odd polar align issue
Thanks Brian,
I am planning to re-run this all step by step hopefully tonight. I am not doing any Gemini PEC, I just enabled the PPEC algorithm in PHD2 - I thought that was the recommended one to pick. Maybe I should have just used the default?
Some of the guide calibrations failed because for an unknown reason my wifi router is not reliable when I use it outside and I have a replacement coming today. So sometimes calibration would fail with a timed out command to the mount, which is causing some noise in the logs.
The GA definitely indicates poor PA which was surprising since I've been using Sharpcap for a while now and getting (what I thought) were good results.
I'll snap some pics of the rig later today. It's a pretty small payload (60mm refractor & small guide cam). I only have two cables coming off the mount (12VDC and a USB3.0 cable)?
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Re: Meridian Flips and NINA
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The mount does random gotos during meridian flip, and in this case it moved the DEC axis 90 degrees from where it was supposed to point.?
90 degrees?is a little too specific?for a random goto bug. That sounds more like a settings issue
On Mon, Jun 28, 2021 at 9:49 AM "Guilherme V¨ºnere < venere@...> wrote: Hi Jim
I haven't tried yet, but I can try tonight. Yesterday after my failed test I went back to 1.10 HF3 and restored my config which worked before. This morning when i went outside to check on the scope, it was again pointing?to the North?horizon like this:
This happened after the flip was done, while NINA was attempting to do the Plate Solve. It happened before, and I think it's related to a bug I reported here a few days ago, which seems to be caused by Gemini firmware. The mount does random gotos during meridian flip, and in this case it moved the DEC axis 90 degrees from where it was supposed to point. So while the flip worked, I still lost half of my session :(
Guilherme
On Mon, Jun 28, 2021 at 9:15 AM Jim Waters < jimwaters@...> wrote: Peter, Guilherme
Have either?of you tried Edward's or my settings?
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Jim W
Phoenix, AZ. USA
Losmandy GM811G, NINA 1.11, ASI2600MC Pro, Sky-Watcher Scopes
-- Brian?
Brian Valente portfolio
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Re: Very odd polar align issue
Based on this data, i'd say your polar alignment is off by quite a bit, and the GA also indicates this
looking at your guidelogs, i think you are trying to do too many things at one time (PPEC algorithm, etc.) - I think the baseline guiding is really the best place for you right now
i'm also wondering about your scope balance, snags, etc. can you send a couple pics of your setup?
are you doing any sort of PEC?
Thanks Brian,
Here is a logfile. Some of the data is during guiding, and some from guiding assistant
-- Brian?
Brian Valente portfolio
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Re: Meridian Flips and NINA
Hi Jim
I haven't tried yet, but I can try tonight. Yesterday after my failed test I went back to 1.10 HF3 and restored my config which worked before. This morning when i went outside to check on the scope, it was again pointing?to the North?horizon like this:
This happened after the flip was done, while NINA was attempting to do the Plate Solve. It happened before, and I think it's related to a bug I reported here a few days ago, which seems to be caused by Gemini firmware. The mount does random gotos during meridian flip, and in this case it moved the DEC axis 90 degrees from where it was supposed to point. So while the flip worked, I still lost half of my session :(
Guilherme
On Mon, Jun 28, 2021 at 9:15 AM Jim Waters < jimwaters@...> wrote: Peter, Guilherme
Have either?of you tried Edward's or my settings?
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Jim W
Phoenix, AZ. USA
Losmandy GM811G, NINA 1.11, ASI2600MC Pro, Sky-Watcher Scopes
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Re: Very odd polar align issue
Thanks Brian,
Here is a logfile. Some of the data is during guiding, and some from guiding assistant
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Re: Very odd polar align issue
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I did some guiding, and I was around 1.0 total RMS and surprisingly DEC was really low (around 0.5) and my understanding of a bad PA is that it would likely show in DEC more than RA.
not necessarily - it would show as corrections primarily (or only) in one direction. if you can upload some guidelogs we can tell pretty quickly. PA is important, but I think the need for highly precise PA is a bit overrated. Guiding is ideal for removing larger periods or drift. it's critical only if you are doing unguided
Thank you both. Great info Michael, I'll definitely be checking all these areas
Brian: I did go through that document but I also tried a lot of other things so my PHD logfiles are not clean. I will need to redo this
I did some guiding, and I was around 1.0 total RMS and surprisingly DEC was really low (around 0.5) and my understanding of a bad PA is that it would likely show in DEC more than RA.
At some point I may need to look at my guiding equipment. I have 6.45 arc seconds/pixel on the guider as I got a small setup to keep the weight down for the skyguider
I also tried a couple of test subs and I was able to get 5 and 10 min subs with reasonable FWHM and eccentricity (although not hugely better than 180s with my Skyguider, but much longer subs)
I'm sure it is something silly I am doing and not anything wrong with the mount
I'm also going to do the Sharpcap PA twice, with different rotation directions - I am suspecting something was off here but I dont know what as I have been using it for a year on the star tracker
I'll be able to try it tonight or tomorrow and report back
Thanks so much for all the help
-- Brian?
Brian Valente portfolio
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Re: Very odd polar align issue
Thank you both. Great info Michael, I'll definitely be checking all these areas
Brian: I did go through that document but I also tried a lot of other things so my PHD logfiles are not clean. I will need to redo this
I did some guiding, and I was around 1.0 total RMS and surprisingly DEC was really low (around 0.5) and my understanding of a bad PA is that it would likely show in DEC more than RA.
At some point I may need to look at my guiding equipment. I have 6.45 arc seconds/pixel on the guider as I got a small setup to keep the weight down for the skyguider
I also tried a couple of test subs and I was able to get 5 and 10 min subs with reasonable FWHM and eccentricity (although not hugely better than 180s with my Skyguider, but much longer subs)
I'm sure it is something silly I am doing and not anything wrong with the mount
I'm also going to do the Sharpcap PA twice, with different rotation directions - I am suspecting something was off here but I dont know what as I have been using it for a year on the star tracker
I'll be able to try it tonight or tomorrow and report back
Thanks so much for all the help
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Re: Meridian Flips and NINA
Peter, Guilherme
Have either?of you tried Edward's or my settings?
------------------------
Jim W
Phoenix, AZ. USA
Losmandy GM811G, NINA 1.11, ASI2600MC Pro, Sky-Watcher Scopes
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Re: Changing the servo motor encoders from 256 to 512 or 1024. Any reason not to do this?
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I estimate the weight of the gear will be around 65 - 70lbs.
the spec of the G11 is 60lbs imaging, 75lbs visual
Michael,
Thanks for this info. I assume the grease is for the worm? Your rig looks quite heavy. How much weight are you sporting? I have a 12" truss Newtonian that I want to mount in the fall. It seems from looking at your setup my G11 should be able to handle it? I estimate the weight of the gear will be around 65 - 70lbs.
I'll defiantly give the loose hanging weight a go. One thing to note, with the worm blocks removed you have very free rotation so easy to get a precise balance.?
Thanks for all the support guys,
??
Peter
-- Brian?
Brian Valente portfolio
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Re: Changing the servo motor encoders from 256 to 512 or 1024. Any reason not to do this?
Michael,
Thanks for this info. I assume the grease is for the worm? Your rig looks quite heavy. How much weight are you sporting? I have a 12" truss Newtonian that I want to mount in the fall. It seems from looking at your setup my G11 should be able to handle it? I estimate the weight of the gear will be around 65 - 70lbs.
I'll defiantly give the loose hanging weight a go. One thing to note, with the worm blocks removed you have very free rotation so easy to get a precise balance.?
Thanks for all the support guys,
??
Peter
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Vishal,
I also recommend going for the G11 with your 130mm refractor.? I originally purchased a GM811G to carry a small 85mm refractor, then bought a G11 dec when I upsized to a 130mm refractor.
I found dec backlash easier to control with the larger worm wheel on the G11 dec axis.? The longer saddle clamp on the G11 is also nice to use with when mounting longer scopes.
I can feel the weight difference between the two if I'm carrying either mount in one arm (the 811 is definitely "easier"), although I can't think of a time when this has mattered.
Thanks,
Dwight
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Re: Changing the servo motor encoders from 256 to 512 or 1024. Any reason not to do this?
Peter...
You have revealed a clue to your RA drive issues: your 240 sec error (worm fundamental period) depends on which side of the meridian you are targeting.
Try this:
1. Fully balance your RA by testing the motor (total Gemini) current with the counterweight bar horizontal.? Adjust your DEC balance first, then balance your RA to get to minimum total Gemini power current.
2. Wrap a length of flexible cord, such as clothesline, around the RA axis do that the cord hangs off the? East side of the RA.? This direction minimizes ring gear chatter.
3. Tie a one or two pound weight to the cord, so that when the RA rotates during imaging, the weight does not bump the tripod or other part of the mount.
That torque from the hanging weight will provide a constant torque to the RA worm and ring gear and always "preload" the contact surface.? In this way the contact region will not flip over as you image through the meridian.?
Then take your PE data on both sides of meridian, and see what your results look like.? I'll hope your flippin' problem is eliminated.
Here is how this appears on my G11T.??
I suggest use of the CRC Brake and Caliper grease to minimize worm to ring gear "chatter" that was observed by me and others....if you put the wrapped cord hanging off the West side by mistake.? This particular grease has 3 lubricants: MolyD, Graphite, and Teflon in a heavy very wide temp range (-30C to +200C?) anticorrosion grease.? It eliminated chatter observed using other greases like Super lube.??
Best of luck,
Michael
Alan,
I will try a rigid one piece coupler. My RA has the OPW. I've found it's possible to feel it the gearbox is aligned or not with the coupler by rotating worm with your fingers. The nice thing about the Mclennan gearboxes is they have a metal plate.??I have removed the motor cover as is is really cosmetic, so will then be able to use a hex head screw to tighten down the motor box more sensitively to hopefully get a good alignment. My planned testing on this issue is as follows.
1. Install a new worm undamaged by the use of the Oldham coupler set screws. Use a dial caliper to measure any wobble in the worm for a baseline measurement.
2. Install the gearbox using two different clamp style couplers from Ruland. I have already posted the part number of one and will get the part number for a rigid coupler if there is one with the correct O.D. Repeat the dial measurement.
3. Run an imaging session and get new FFT data.
The reason for these tests is mostly to better understand to magnitude of errors caused by different elements in the drive chain. I've already demonstrated how much better the FFT looks with the 125:1 gearbox in terms of higher frequency components. I'll be testing the 50:1 and 80:1 gearboxes in near future too.?
Currently, there is an 80s and a 240s error as show early in the FFT plot I posted. These have a corrected magnitude of 0.35 arcsec using the hysteresis PHD2 algorithm. I've not found the Predictive PEC algorithm works. These numbers change depending on which site of the meridian I'm on. Usually, after the flip the 240s goes away completely, but since my current project is the Cygnes Wall no flip has been needed so the error is a problem for the resolution I'm at.
Peter
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Paul Kanevsky
Greg
Edward Plumer
Michael Herman