Hi,
I have only had 2 nights since Mar with no cloud.? I lost both of them to something that sounds similar.? PHD2 could not calibrate DEC, and when I started guiding, it showed a classic control overcorrection, with the variance in both dec and RA increasing with each correction.? Not sure if I have the logs, and perhaps if I do have them they may not be so useful, as it made no sense to just let the guiding run.

While searching/finding the relevant PHD fault finding guide for some inspiration, I bumped into a post that indicated that a re-install of PHD2 back to the earlier version had worked for that OP.? Sorry, I cannot recall whether the last time I tried imaging whether the latest PHD2 update had applied.? I did a quick re-test and it seemed PHD was working again.

I am very new to the "game" so it is also more than likely the error was the human operator.? Though for the failed evenings, I did pull down and reset up from scratch both nights.

Maybe/maybe not helpful?

Cheers, Phil

LKO,

What you are seeing I think is typical behavior for balancing. Since RA has some downward weight going into the clutch disc, there will be some stiction and it will not swing perfectly free.?

With the Dec axis horizontal, the is little to no contact with the clutch and motion is less restricted. I go just camera heavy in Dec which is fine for my guiding output. But it sounds like you are close to the balance point with your swings and you shouldn't need to sweat it any further. If there is any problem with Dec guiding in PHD2 or whatever you are using, then you might revisit the Dec balance. The balance does not need to be perfect for the mount to function well.

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

On Tue, Aug 9, 2022 at 01:24 AM, Brian Valente wrote:

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and marked where that was on the guidescope.

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Thanks for sharing and reminding the oppositions are coming!

I'd assume if you sync the guide camera to mount, slew to the planet, adjust the mount to center image on the main camera, and then plate solve you would obtain (p2 - p1) the planet position offset in RA/DEC.

Then if the synced guide scope were not changed from use to use, the offset added to the current planet position should provide the main camera offset slew position.? At least after the initial slew with a plate position or photo confirmation that the guide scope is centered.? Sounds promising and a lot better than fiddling with high power finder guide rings given the dedicated equipment during opposition.

Enough usability to support the concept (just to stay on subject).

Finally got a reasonably good night and after updating PHD2 and finding a good star in NE soon noticed that DEC was drifting which increased over exposure time.? I am using a STi as a guider.

My question is whether others have fount this issue and how did they solve it?? I did several weeks check the balance of the unit and it was spot on east or west with all gear on mount/scope/camera & all cords etc.

Please note that I am not sure I have the corrects settings in PHD2 to increase the response to the DEC so any suggestions about PHD2 would also be appreciated.? My scope by the way is a Tak E180 and the guide scope is a Televue scope usable for terrestrial or stars.

Thanks in advance for any help/suggestions to check.

Doug Askew

Interesting extension, how did you align the guide camera to the narrow field main camera?

It also seems like a pretty small guide scope should work and provide a larger field.? At least with a small pixel camera for this purpose.

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Dereck,

6 arc minutes is a tiny FOV, I would align with a lower power eyepiece and then swap if for a higher power.

Paul

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That’s what I said in the post you responded to! It says..

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I used a camera and changed the Region of interest.. If you use eyepieces, like I used to do, start out widefield until you locate the target, then increase the power – i.e take the time to be exact as possible before adding them to the model..

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I use the camera as a set of eyepieces, locating the target at around 3,000 x 2000 pixels, center on the crosshairs, change the Region of Interest to 640x480 and center better, then synch and align.. It was after the third star was entered into the model – from my 6 arcminute Region Of Interest Camera view - that I just happened to do a GOTO back to all three model stars – without changing back to the full 3,000 x 2,000 pixels - that I was SHOCKED they were all perfect.. Sorry that wasn’t clear..

??? HOWEVER! When I tried it again last night, It worked perfect for the first star.. Arcturus was in the (widefield ROI) of the camera.. A GOTO to Antares was not, but it was in the guidescope, so easily centered and synched on..

??? My (widefield ROI) is somewhere around 20 arcminutes, so it SEEMED it was another “it stopped short by a half moon diameter / 15 arcmin”.. It is this “works one day but not the next” issue why it is – to me – much more important to have proper pointing devices and adequate scale between them so even if things are perfect, it’s a very simple matter to get back on target and continue on..

??? Derek

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On 7 Aug 2022, at 3:48:40 pm, Derek C Breit <breit_ideas@...> wrote:

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(I had to calculate my FOV.. It is listed as 0.1 x 0.07 degrees, so 6 arcminutes..)

This may include an extra step or so, as I was always told not to align on the first star.. Anywho, this is what I just did.. Maybe it’ll work for you!

My settings are correct.. I have a new battery, I reset CWD. I did a cold start.. My clock runs very fast, so I use my cellphone and set it to the second and hit the SET button when appropriate.. I do this on every powerup.. I live in?Morgan Hill,?CA?and this was around 8:30 PM.. aka a little while ago..?

I did a goto to Arcturus. Laser should it as it normally is, which is HALF a moon diameter away, almost entirely in RA.. (I use the tactile buttons on the back on the hand controller.. Coiled cord points away from me.. The button is what I need to center the target.. Also takes just a touch north in Dec.. I mention this for the “Stops Short” idea.. )..

Anywho, I centered Arcturus, and SYNCHED..?

GOTO Antares, Center.. SYNCH.. ALIGN..?

GOTO Arcturus.. Centered it, as it was off towards the top left, and ALIGNED..?

GOTO Vindemiatrix and it is nowhere to be found and I didn’t try! I did a Goto to Arcturus.. On the way, I saw Vindemiatrix flash by.. *Importantly* Arcturus was in the same top left corner it was previously, so I went to MENU / ALIGN / UNDO LAST ALIGNMENT.. This time I centered Arcturus, SYNCH, then ALIGN..?

GOTO Vindemiatrix, Center SYNCH, then ALIGN..?

Arcturus to Vindemiatrix is around 20 degrees.. Arcturus to Antares is ~ 56 degees.. Antares to Vindemiatrix is ~ 62 degrees.. Not the best choices, but good enough.. Now I have three stars in a model on the West. And?regardless of which order I went to them via GOTO, they were all quite close to being centered in my little 6 arcminute FOV.. My guess is they were all within 2 arcminutes of being perfect..

I used a camera and changed the Region of interest.. If you use eyepieces, like I used to do, start out widefield until you locate the target, then increase the power – i.e take the time to be exact as possible before adding them to the model.. and remember, SYNCH, then ALIGN.. The “New” thing for me was to try and go back to previous stars to make sure they were correct before adding another one, as if it is wrong in any way, you can “UNDO LAST ALIGNMENT”..?

I parked it at CWD and will do a WARM RESTART and see how it works next time out.. :-))

Derek

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From:?[email protected]?[mailto:[email protected]]?On Behalf Of?Derek C Breit
Sent:?Saturday, August 06, 2022 9:54 PM
To:?[email protected]
Subject:?Re: [Losmandy_users_io] Usability Question

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Put the Counterweight bar horizontal , use the clutch knob as needed, and level with a torpedo level.. Spin the RA dial and set it to something like 18 hours.. Loosen clutch and lower the Counterweight bar and set it at 0 hours.. Lock the clutch.. Loosen the other clutch and adjust the scope until the level on the dovetail is centered.. Tighten clutch.. Your visual, so do this “well” but do not obsess with it.. I have a solution for you to try.. Just worked perfectly for me.. First time and I am quite pleased about it!

See next email.. It’ll take a minute..

Derek

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From:?[email protected]?[mailto:[email protected]]?On Behalf Of?Mark de Regt
Sent:?Saturday, August 06, 2022 8:53 PM
To:?[email protected]
Subject:?Re: [Losmandy_users_io] Usability Question

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Agreed about “should.”???

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What is the best method for making sure I have CWD a good as possible?

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From:?[email protected]?<[email protected]>?On Behalf Of?Paul Homer
Sent:?Saturday, August 6, 2022 8:21 PM
To:?[email protected]
Subject:?Re: [Losmandy_users_io] Usability Question

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Mark,

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Assuming you are polar aligned it is not just the CWD position that matters but the top of the dovetail should also be levelled, both with a small level.

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This is easy and quick and should get you fairly close.

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Then centre the star and synchronise the first star.

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If you are not so closely polar aligned then take the time to do alignments on three or more stars spread across the sky.

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This sill build a pretty accurate model and no camera is required.

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It will need to be rebuilt if you move the mount, but should only require a synchronisation if you only warm start.

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Paul

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On 7 Aug 2022, at 8:41:23 am, Mark de Regt <deregt@...> wrote:

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OP here again.

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I really appreciate all the suggstions!

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Two things have resonated:

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1. I only guestimate CWD position with my eye.? If precision of CWD matters, and if there is a simple way to get it perfect, that may be the cause.
2. People keep taking about using plate-solve to work around the poorly-functioning Gemini2 model building.

1. I need a camera to do that; I’m happy to buy a cheap camera for that, but not an expensive one; any suggestions?
2. I own TheSkyX Professional Edition, a very powerful planetarium program.? Would this do that is being suggested, and, if so, how?

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Thanks again!

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Mark

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Virus-free.?

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