Re: Bright Star disappeared from list despite being well above horizon
>>>I just want to assure you that those things are NOT factors.
If what you are describing is accurate (i'm not saying it isn't, but assuming no errors in how you are building your model, etc.) this is literally the only way your gotos can consistently be off.
There isn't any other obvious explanation. Is it possible there's a diode blown somewhere or something else? sure it's possible, but the likelyhood if it *only* affecting your gotos under specific circumstances is very low.?
I encourage you to try the other post i mentioned
I just was talking to someone who assured me up and down their location was 100% accurate, checked their gps, etc. and it turns out they had a + and - sign reversed
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Re: Bright Star disappeared from list despite being well above horizon
Thanks, Brian, but no, that is not it.? I even did a factory reset just to be sure nothing was stored that was interfering in some way.? I have checked and re-checked location data -online, with my wife's smartphone GPS app, and also with a Losmandy-supplied GPS unit, and it was all the same, and I set up at the exact same spot every time I'm out.? I've entered and re-entered that data just to be sure.? I use UTC, not local time, and have checked and re-checked that too.? At some point, you have to be 100% confident!? And from the number of "pointing" issue threads I've seen about Losmandy mounts here and elsewhere, well, I realize a good bit of it could be user error, but certainly not all of it.? But thanks for the suggestion in any event.? I just want to assure you that those things are NOT factors.
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Hi Kenn,?
Both my Losmandy GM8 and G11 do this even with a leveled tripod and a scope with no finders, guiders, cameras etc. just the OTA in the rings. The mounts always behave the same way and favor the same side regardless of OTA or altitude. I have even tried to eliminate this slight imbalance by ensuring that the counterweights have their locking screws pointed down and without DEC DIN cable plugged in and tried flipping the saddle 180 degrees.?
I have no idea why it works like this but it doesn't seem to hurt the guided or unguided PE so I ignore it and just get the balance as close to even as possible. But even so it is not critical for imaging or visual using the mount as it was designed in PUSH-TO mode as long as you are reasonably close. When observing visually about 95% of the time I have a 1.25" eyepiece in the diagonal so there is virtually no balance change between eyepieces even when moving from a 24mm Panoptic to a 35mm Panoptic the scope needs no rebalancing.?
--
Chip Louie - Chief Daydreamer Imagination Hardware
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I can see this has been discussed a lot here, and am going to take some time to read some of the threads on it later, but just wanted to add my voice, and could not find any discussion later than 2017 (doing a search just for "pointing.")? I'm sure there are others who've had problems with pointing since then.
I have a GM811G.? As far as I can tell I've done everything according to the book (and videos and some discussions I've read on Cloudy Nights and elsewhere).? Checked battery.? Did factory reset and re-entered parameters just to be sure that wasn't a factor.? I use UTC, not local time.? Made sure balance was good.? Checked and double-checked leveling with CWD.? Got great polar alignment with PoleMaster.? Did the modeling routine according to the directions.
And pointing was still off - sometimes way off.? Went to a catalog object and it was not even in my camera viewfinder screen.? To give an example, after modeling, I slewed back to Arcturus to focus, then slewed to Spica, and it was not nearly centered.? Did an alignment on Spica.? Slewed back to Arcturus, and IT was now well off center.? Did the alignment routine on Arcturus, then slewed to Mizar.? WAY off!? Aligned on Mizar (yes, according to the prescribed routine of Menu> Align > Bright Star > Center > Align > Alignment.? Went back to Arcturus, and it was still off.
The only way I'm currently able to center objects I want to image is by slewing to a brlght star somewhere near the object, performing the alignment routine, then slewing to the object.? Even then, I sometimes need to make slight corrections to center the object a little.? When I bought this mount (hardly used, practically like new), I was had high expectations to be done dealing with this sort of thing (and we won't get into tracking, which is good, but not as good as I'd hoped, even with good seeing).? I do really like the mount, and just hope I'll be able to do something to get it to point (and maybe track) better.
So, I have absolutely no idea where to go from here.? Just hoping something will "click" that either I'm doing wrong, or the Gemini 2 is doing wrong.
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Re: Bright Star disappeared from list despite being well above horizon
Assuming you are building a pointing model correctly, and your gotos on the same side of pier are still off, 99% of the time it's bad date/time and/or location information
also the majority of the time when people say "my date/time and location is correct, i am 100% confident" it ends up being one of those values is off
Just a follow-up.? Two nights ago was a night from hell, like all of us have now and then.? Just could not get good pointing and tracking, despite very good seeing, and finally gave up after about 2 hours of having my patience tested.? Last night was much better, but I'm afraid I'm going to have to spend some time reading the "pointing woes" threads here.? What I've been having to do is align on a star close to the object I want to image, and then going to that object.? Otherwise, pointing is not real great most of the time.? I slewed to Denebola, which was not centered real well, but ok, then tried to slew to M65, which is right nearby, and it wasn't even in my first camera shot (at ISO 6400, just to see if the object was there).? Slewed back to Denebola, which was no longer centered, did an alignment on it, then went back to M65, and that worked.
And once again, Sirius was no longer on the BSL, even tho' it was still well above the horizon.
-- Brian?
Brian Valente portfolio
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Re: Bright Star disappeared from list despite being well above horizon
Just a follow-up.? Two nights ago was a night from hell, like all of us have now and then.? Just could not get good pointing and tracking, despite very good seeing, and finally gave up after about 2 hours of having my patience tested.? Last night was much better, but I'm afraid I'm going to have to spend some time reading the "pointing woes" threads here.? What I've been having to do is align on a star close to the object I want to image, and then going to that object.? Otherwise, pointing is not real great most of the time.? I slewed to Denebola, which was not centered real well, but ok, then tried to slew to M65, which is right nearby, and it wasn't even in my first camera shot (at ISO 6400, just to see if the object was there).? Slewed back to Denebola, which was no longer centered, did an alignment on it, then went back to M65, and that worked.
And once again, Sirius was no longer on the BSL, even tho' it was still well above the horizon.
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While I can see Astroshed's Newtonian does achieve balance in the vertical position, am I the only one who notices his focuser/eyepiece winds up in a potentially unusable position? (Basically CWD the focuser appears to be under the scope.)
I'm all for better balancing, and I do my best. But I want to see how I can improve it.
Rotating my scope may well not be feasible since I use a smaller refractor, and my focuser is limiting in what could be done. (Basically impossible, without major revisions. But that is a personal problem.)
I'll play with these thoughts of balance on the vertical. And it goes against my common sense to be rigging up ropes and pulleys.
I have to lug my equipment out, and then back in every night I use it (which is almost every clear night.) So my thoughts are that any balancing tricks have to be more along the lines of highly mobile, and of a fixed nature.
But a lot of it is, in my honest opinion, not too critical as my "Payload" is 15.6 pounds of photographic Astro equipment from the clamp up, including my bar.
And this is riding my GM811G HD mount, which we know has a 50 pound Photographic Instrument weight rating. Which is a capacity ~3.33 times my load. So it is quite a bit stronger than my fly weight load it bares.
I'm interested in these better balancing ideas, because I can see room for improvement in my PHD2 graph. But I really only put faith in the Photographic results.
Interesting topic though.
--
SonnyE
(I suggest viewed in full screen)
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Re: Beginner: how to adjust G11 altitude bolts?
Dear MB,
Losmandy has replacement knobs that go in place of the Allen head screws and are much easier to work with than the original altitude locks.
I have found these really help with the final fine tuning where you may have to loosen and tighten each side several times. Since you don't need a wrench anymore, it simplifies tweaking in the dark. You may find a progressive side to side tightening works better than just one twist on each, and then do a recheck after every adjustment. Other brand mounts and wedges have a similar routine.
Best Regards.
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Hi Kenn
usually one side of the axis is "looser" than the other when balancing. for DEC you can also rotate the RA axis past parallel to the ground to loosen up the axis even more
regarding improved guiding, i think that's just coincidence. There are so many things that go into a good night of guiding it would be unlikely that slight rebalancing (it sounds like you do a good job on balancing in general) would make much of an improvement.?
happy to review your before/after guidelogs if that's the case
Brian
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Re: Beginner: how to adjust G11 altitude bolts?
Hi England
you have some good advice here, i'd like to offer a few more tips
1. yes you should loosen both, but just enough to move the alt adjustment. you don't want to loosen them completely
2. If you want accurate polar alignment, it's usually an iterative process of tightening and moving, tightening some more and moving.?
3. i tighten them as tight as I can get. If you try, you will still be able to move them, given the force you can apply from the adjustment knob, so don't worry it you can still move it.
4. why are there two? two is better than one! more secure
also just making sure you are loosening the alt adjustment bolts (top ones on each side) and not the two bolts beneath them that hold the RA axis together
Brian
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Re: configuring ethernet/microrouter for gemini
Count me in for a zoom meeting! Mearl In VA
On Thu, Apr 23, 2020, 1:27 PM Brian Valente < bvalente@...> wrote: there's been an ongoing discussion about how to hook up your gemini via ethernet/wifi
i'm thinking of doing a zoom meeting or possibly facebook live this weekend to go through this setup. (we are eventually going to do a tutorial video on this, so think of it as a dry run to see what questions come up)
maybe sunday as several people are getting their routers on saturday
what interest/preference is there for something like this?
(the discussion is here if you are interested)
I recommend and use this particular microRouter:? ?)
you will need at least 2 ethernet cables (cat5/6)
-- Brian?
Brian Valente portfolio
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Re: The First Mars Helicopter Will Fly with Maxon Motors
On Thu, Apr 23, 2020 at 06:19 PM, Brendan Smith wrote:
maxon motors are around $300 AUD alone...!?? I would also need a machined housing.? Spent the last 2 weeks going over motor specs from many mfgrs...it's a minefield!
Ouch :-/ Good luck in your endeavor ;-) Cheers, Carl
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Hi Ken,
I have experienced similar balancing issues. If you achieve perfect balance the scope should stay still in absolutely any position you set it.
For me the key to achieve that is to not only level DEC horizontally (moving scope, at 0¡ã relative to ground, forward or backward) but also vertically (rotating scope, at 90¡ã relative to ground).
This video explains it much better than I did (relevant part from 5:30 onward):?
Edit: I should add that if you don't have a spring loaded worm gears, then you do not wan't perfect balance, you want slight east heavy balance.
But IMO the best is still to get perfect balance and then add the "RA worm string bias trick":?
Cheers,
Carl
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Re: Beginner: how to adjust G11 altitude bolts?
Generally I found that the only one I need to slacken is the upper Allen bolt that runs in the machined arc (unless the lower one is tightened up really hard). ? If you have backlash when adjusting the hand wheel then you need to tighten up the collar that increases the load on the thrust bearing which bears on the base of the knob there was a discussion of this recently and the following two post by Chip Louie are relevant: ? /g/Losmandy_users/message/59847 ? and ? /g/Losmandy_users/message/59878 ? This website in Italian may also be helpful: ?
? If the altitude mechanism seizes when you try to turn the knob something is rather amiss. ? You should snug both set of Allen bolts after adjustment. ? As you¡¯re in the UK, if you can¡¯t sort it out, I¡¯m happy to look at the problem for you either via webcam (maybe Skype) or in person after the lockdown if you can bring the mount to me. ? David ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Paul Homer
Sent: 24 April 2020 10:09
To: [email protected]
Subject: Re: [Losmandy_users_io] Beginner: how to adjust G11 altitude bolts?? England, I would loosed the bolts slightly while polar aligning and then tighten them once aligned - more than finger tight. ?
? Hello from England.?I'm a newcomer to Losmandy products. I cannot fathom the G11's 2 allen bolt altitude adjustment. Please can someone answer: - The hand knob only declines the mount head, and semi-seizes when trying to incline it.
- Common sense say both altitude bolts should be slackened to enable adjustment. Should they only be done up finger tight once set?
- Mechanically, why are there?two?locking bolts?
Thanks in advance. ?
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Re: Beginner: how to adjust G11 altitude bolts?
England,
I would loosed the bolts slightly while polar aligning and then tighten them once aligned - more than finger tight.
toggle quoted message
Show quoted text
Hello from England.?I'm a newcomer to Losmandy products. I cannot fathom the G11's 2 allen bolt altitude adjustment. Please can someone answer:
- The hand knob only declines the mount head, and semi-seizes when trying to incline it.
- Common sense say both altitude bolts should be slackened to enable adjustment. Should they only be done up finger tight once set?
- Mechanically, why are there?two?locking bolts?
Thanks in advance.
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Previously when I balanced my scope/mount I start with the DEC. I set the RA to be parallel to the ground and I usually balanced the DEC so when the front of the scope is pointing North the scope stays parallel to the ground also. I can touch the scope and no matter how much pressure I place the scope it will stay in that position-just a little eye piece/camera heavy.
Today, after I changed scopes and balanced DEC, I also moved the scope to point South with some interesting results. The front of the scope moved up about 5/6 inches; interesting. I then moved the scope so it pointed North and it stayed level; interesting.
I then pointed the scope straight up and the front of the scope moved North. OK, I decided to balance the scope so it would move, slowly, back to almost straight up. I¡¯ve never had PHD2 track better using a FLT132 925mm scope as the guider. I balanced RA as I usually do, no changing the balance routine method with RA
Any comments would be welcome.
Kenn
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Beginner: how to adjust G11 altitude bolts?
Hello from England.?I'm a newcomer to Losmandy products. I cannot fathom the G11's 2 allen bolt altitude adjustment. Please can someone answer:
- The hand knob only declines the mount head, and semi-seizes when trying to incline it.
- Common sense say both altitude bolts should be slackened to enable adjustment. Should they only be done up finger tight once set?
- Mechanically, why are there?two?locking bolts?
Thanks in advance.
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Re: The First Mars Helicopter Will Fly with Maxon Motors
Thanks Carl but maxon motors are around $300 AUD alone...!?? I would also need a machined housing.? Spent the last 2 weeks going over motor specs from many mfgrs...it's a minefield!
--
Brendan
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PHD2 gives me an odd graph with my GM811G HD set up.
But what tells it all is my imaging results. As long as I'm getting great guiding and tracking (and I am),
I don't really care what sort of hash PHD2 shows.
Don't get hung up on PHD2 graphs. They can vary like the weather.
Pay attention to your results. That's the Proof that's in the Pudding.
PHD2 is to latch onto a single star, then follow it. And it can do that well enough for Photographic results.
Especially with your new mount. Mine does.
--
SonnyE
(I suggest viewed in full screen)
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Steve
also FYI the spring-loaded worms do not register well with the backlash measurement in PHD. If you review your actual guiding results you'll see they are quite good (i'm assuming the 1.1 arcsec/pixel is from guiding). you can't get that with a backlash of nearly 34 seconds.
Bruce and Andy and I have discussed this ad nauseam?
If PHD only worked with losmandy mounts?i think they would remove that warning, but there are many other types of mounts for which this is a helpful bit of information.?
On Thu, Apr 23, 2020 at 12:51 PM Steve Elmore via <gizmo_s67= [email protected]> wrote: I received my new GM811G and finally got out under the stars to start learning the mount and Gemini 2 system.? Before I got started, I noticed some movement in the DEC axis.? With minimum effort, i can wiggle the saddle, i.e. DEC axis.? I am working with PHD2 and got some messages about the DEC axis, don't remember exactly.? I ran the guiding assistant and I thought the numbers looked good, except for the DEC Backlash was highlighted.? Here are some of the values:
RA Peak? 0.44px(6.73arc-sec)
DEC Peak? 0.37px(5.61arc-sec)
RA Peak to Peak0.47px(7.13arc-sec)
RA Drift Rate-0.09px/min(-1.41arc-sec/min)
RA Max Drift Rate0.04px/sec(0.67arc-sec/sec)
Drift-limiting exposure2.4s
DEC Drift Rate -0.01px/min(-0.21arc-sec/min
DEC Backlash >=34970 +/-99ms(247.1 +/-0.7a....
Polar Alignment Error 0.9 arc-min
High-frequency Star Motion
RA, RMS 0.05px(0.80 arc-sec)
DEC, RMS 0.05px(0.75arc-sec)
Total, RMS? 0.07px(1.10arc-sec)
Should I address the looseness in the DEC axis?? I've watched the video how to adjust the spring-loaded worm gear.? Would that be the way to eliminate the looseness?
Thanks for any help, Steve
-- Brian?
Brian Valente portfolio
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Chip Louie
Mearl Balmer
David C. Partridge
Kenn
Matthew_B