Thanks, Chip.
Any info offhand as to what the tapped holes are threaded for??
greg
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Re: Polaris alignment problem
At 15:28 04-11-17, glatiak@... [Losmandy_users] wrote:
Had an interesting problem last night redoing the alignment and pointing model on my relatively new GM-8. Normally, the northern sky is obscured by trees in my location -- but seasonal change and recent windy weather has cleared the view.
After redoing my polar alignment, I was adding stars to my model and decided to try for Polaris. Got it into the FOV with no problem, was just a bit off. For this I have the HBX motor set to 'center' -- DEC adjustment seemed fine, but I needed to move a bit in RA and found that there was great reluctance to this. I had to hold the button down for an extended period to see any movement at all. Finally got it centered, did the alignment. But subsequent gotos were off -- as though the scope had slid on the clutches. No apparent mechanical issues, cables loose, scope was fully balanced. Clutches as tight as seemed reasonable.
So I parked things, shut it off, dug out the level, found that the RA had shifted a bit. Corrected it and restarted. Now the goto's were dead on.
Not wishing to be insult you; but are you sure that the mount was still level and that one of the legs hadnt dug itself further into the ground? David
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Re: Polaris alignment problem
Sounds like hardware, you might double-check all your mount connections and screws and tighten them
sometimes i've found the screws to my tripod were left slightly loose
B
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Greg,
This is a design feature leftover from the days of digital setting circles and not used by any current accessories that I know of.?
Chip
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I am curious about a feature on my GM-8... at the bottom of both the RA and DEC axis there is a flat with what appear to be two threaded holes. Were these intended for some feature? Or an artifact of an old one? Could they be used to mount a level to achieve consistent setups?
Thanks,
greg latiak avalon observatory
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Re: Polaris alignment problem
I think there us a discussion in the "setting up your mount" area of the Losmandy G11 mount manual...or else download the manual for the Orion Atlas that also discusses it.??
Basically you have to shim where the scope mounts to the dovetail,? while you rotate the RA by 180 degrees... until you get the exact same eyepiece image at both rotations.? Then you have zero cone angle error....
(For me, it's like drift aligning...I fight against doing it til I realize there is no other way...)
Best,?
On Nov 4, 2017 9:07 AM, " glatiak@... [Losmandy_users]" < Losmandy_users@...> wrote:
?
Thanks.
I have read about cone angle and have a mental picture of what it is, but have no idea how I would go about measuring it on my little scope, let alone correcting it. So the answer is no, I didn't...
greg
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Re: Polaris alignment problem
Michael,
The next goto was to Capella, a star that I had already used in my model. I was curious if something had shifted -- and it had. That is what made me stop, CWD, restart. Then I pointed it at Capella again (was there now) and did a synch. Everything after that was great...?
greg
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Re: Polaris alignment problem
Thanks.
I have read about cone angle and have a mental picture of what it is, but have no idea how I would go about measuring it on my little scope, let alone correcting it. So the answer is no, I didn't...
greg
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Re: G1 on G-11 refuses to go to bright stars
Magnus,
We've recently found some bad EPROMs that lose code data prematurely...sometimes in months. ?(They were supposed to hold for 100 years when I engineered them in 1985... ). So an easy test is to get another one to try.? David Partridge nearer you has them... You should get one and try that. ??
All the best, Michael
?
Hi!
Yes, it occurs with slews to DSO-objects as well. My EEPORM was upgraded to level 5 someting like 2 years ago (I bought the mount second hand 3 years ago, then upgraded many things like EEPROM and motors).
I can test with motors off in a few days time (too busy this weekend). I can try anything, that might give a clue :)
And of course, Michael, I'll try what you suggested. Coming back with a report.
Yes, I do have a digital multi-meter. I don't know if I'm handy with it, but I can measure resistances and voltage at least :) What could I do with it?
My own hunch here, for whatever it is worth, is precisely some kind of corrupt data. I was thinking "corrupt point model" but that could not apply to a cold start, right?
Next idea I have, coming from some messing with computers, is that sometimes you get strange and inconsistent, intermittent, behaviors when hard drives or RAM is corrupt. Could something similar be happening here?
Either way: is there anything corrupt or broken in the G1 as such, I guess this would be the prompt to upgrade to a G2. It is expensive, but honestly, it is doable. Or there may be a spart G1 to buy cheaper out there somewhere? (I cannot persuade myself that the G2 brings that much to my situation, almost exclusively, like 98 %, using the scope remotely controlled through Ekos/Indi - so I don't need wifi and stuff like that, just for the mount to be mechanically robust and for the Indi server to be able to control it - all else is nice but not needed).
So: any suggestions on what to try, or for G1 units to exchange this one for (or even cheap G2:s) are very warmly welcome.
Magnus
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Re: Polaris alignment problem
hey Greg,
Just curious...
When you mounted yor scope, did you test/correct for cone angle of the scope+dovetail?
My reason for asking is that ?I think cone angle would be a T- pointing model parameter, but a large cone error might force the mount to try a weird RA trying to get the scope right at the pole...it might have to rotate RA a lot to try. I find most books and mount manuals recommend mechanically adjusting for that at the scope mount to the dovetail. ?(Though lazy me still has that task to do.)
Also, when you shifted RA, did you then do a "Synch" to just reset the counters and keep the existing pointing model, ? ( not an "Align" that would have added points to the model.)
I guess the good news is that your gotos away from the pole were correct.? That's the biggest piece of sky to find!
Best, Michael
?
Had an interesting problem last night redoing the alignment and pointing model on my relatively new GM-8. Normally, the northern sky is obscured by trees in my location -- but seasonal change and recent windy weather has cleared the view.
After redoing my polar alignment, I was adding stars to my model and decided to try for Polaris. Got it into the FOV with no problem, was just a bit off. For this I have the HBX motor set to 'center' -- DEC adjustment seemed fine, but I needed to move a bit in RA and found that there was great reluctance to this. I had to hold the button down for an extended period to see any movement at all. Finally got it centered, did the alignment. But subsequent gotos were off -- as though the scope had slid on the clutches.?No apparent mechanical issues, cables loose, scope was fully balanced. Clutches as tight as seemed reasonable.
So I parked things, shut it off, dug out the level, found that the RA had shifted a bit. Corrected it and restarted. Now the goto's were dead on.
I am sure I am screwing something up... any insight on this or suggestions?
Thanks,
greg latiak avalon observatory
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Polaris alignment problem
Had an interesting problem last night redoing the alignment and pointing model on my relatively new GM-8. Normally, the northern sky is obscured by trees in my location -- but seasonal change and recent windy weather has cleared the view.
After redoing my polar alignment, I was adding stars to my model and decided to try for Polaris. Got it into the FOV with no problem, was just a bit off. For this I have the HBX motor set to 'center' -- DEC adjustment seemed fine, but I needed to move a bit in RA and found that there was great reluctance to this. I had to hold the button down for an extended period to see any movement at all. Finally got it centered, did the alignment. But subsequent gotos were off -- as though the scope had slid on the clutches.?No apparent mechanical issues, cables loose, scope was fully balanced. Clutches as tight as seemed reasonable.
So I parked things, shut it off, dug out the level, found that the RA had shifted a bit. Corrected it and restarted. Now the goto's were dead on.
I am sure I am screwing something up... any insight on this or suggestions?
Thanks,
greg latiak avalon observatory
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Re: RA rate drift (revisited)
Hi!
THis is really interesting (as are most things related to this tricky issue of PA...)!!
Could you say a little more about how this adjustment at zenith would be done? For instance, I use PHD2 for drift alignment - I guess that is not useful in this situation. So more precisely how could I try this?
Best,
Magnus
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Re: G1 on G-11 refuses to go to bright stars
Hi!
Yes, it occurs with slews to DSO-objects as well. My EEPORM was upgraded to level 5 someting like 2 years ago (I bought the mount second hand 3 years ago, then upgraded many things like EEPROM and motors).
I can test with motors off in a few days time (too busy this weekend). I can try anything, that might give a clue :)
And of course, Michael, I'll try what you suggested. Coming back with a report.
Yes, I do have a digital multi-meter. I don't know if I'm handy with it, but I can measure resistances and voltage at least :) What could I do with it?
My own hunch here, for whatever it is worth, is precisely some kind of corrupt data. I was thinking "corrupt point model" but that could not apply to a cold start, right?
Next idea I have, coming from some messing with computers, is that sometimes you get strange and inconsistent, intermittent, behaviors when hard drives or RAM is corrupt. Could something similar be happening here?
Either way: is there anything corrupt or broken in the G1 as such, I guess this would be the prompt to upgrade to a G2. It is expensive, but honestly, it is doable. Or there may be a spart G1 to buy cheaper out there somewhere? (I cannot persuade myself that the G2 brings that much to my situation, almost exclusively, like 98 %, using the scope remotely controlled through Ekos/Indi - so I don't need wifi and stuff like that, just for the mount to be mechanically robust and for the Indi server to be able to control it - all else is nice but not needed).
So: any suggestions on what to try, or for G1 units to exchange this one for (or even cheap G2:s) are very warmly welcome.
Magnus
|
Re: RA rate drift (revisited)
Gentlemen,
I was recently enlightened about polar alignment and drift in the two axis on the Astro-Physics group.? The polar alignment most of us are used to is designed to provide minimal declination drift, not minimum RA drift.? If we were on the moon there would be no difference.? But due to atmospheric refraction, the minimum declination drift polar alignment results in RA drift.? What Roland Christian recommends is to align the azimuth in the normal fashion minimizing declination drift at the celestial equator and the meridian.? But instead of going East or West to do the elevation adjustment, move? up the meridian to the zenith.? Then adjust the elevation to minimize the RA drift.? Good PEC helps here to identify the RA drift. ?
The difference is that the old method was designed when scopes typically did not have a declination adjustment that could be used in guiding, but the RA could be adjusted for guiding.? So the polar alignment routine was designed to minimize declination drift over the entire sky.? With scopes that can effectively guide in declination, the new polar alignment routine minimizes both declination and RA drift within 30 degrees of the meridian, where most imaging is done.? This can allow for unguided imaging in this range and is still readily guided outside of this range.
I have yet to try this, but the theory seems sound.? Rolando would not steer me wrong.
Greg
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Re: G1 on G-11 refuses to go to bright stars
That's not a bad Idea Michael.? But the "interrupt" only occurs on goto slews not things like "park" slews.? However, that said there is not much else to look at.
Along this line of ideas......Magnus, do you get this with slews to other objects?? Like DSO slews?? Maybe...kinda thinking the EPROM BSO data is bad.? Do you have your old 1.04 EPROM?? Can you swap them over?
Previously I asked if you can take your motors off the mount, keep them connected via their motor leads.? Since the encoders are inside of the motors you can perform "commands" but just the motor pinions spin as the axes are not moved by them.
Thus you can perform "fake" goto slews without actually moving the axes.? Of course you need to ensure the slew command "goto object" is withing the overhead horizon (I use a planetarium just dial in local time etc).
Just asking this to see if taking the axes load off the system removes the "interrupts".?
Lastly along Michael's idea, are you handy wit ha multi-meter?? Do you have one?
Brendan
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Re: GM-11 general lubrication
Dissimilar metals like cres on aluminum (anodized) pose no problem like that but a tiny bit of lube wont hurt if it makes you feel better.
Jeff ?
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Re: G1 on G-11 refuses to go to bright stars
That¡¯s a great idea Michael. ? Perhaps another way you can test this is do the goto from the hand control unit and then unplug it when it starts slewing? ? Thanks ? Brian ? ? Brian Valente Brianvalentephotography.com ?
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Show quoted text
From: Losmandy_users@... [mailto:Losmandy_users@...]
Sent: Friday, November 3, 2017 1:43 PM
To: Losmandy_users@...
Subject: Re: [Losmandy_users] Re: G1 on G-11 refuses to go to bright stars? ? Dear Magnus, Having read all of your misery on this... sorry to read the problem persists. It is quite a mystery, and I can't recall anyone else reporting that type of "interrupted" trouble from a Gemini1 or 2 before. I have only this idea for you to try... Because you can "interrupt" a slew by pressing a hand controller button, I have wondered if there could be an intermittent contact/short in your hand controller buttons. The question is: do you still get this error with the hand controller removed (once you set up). After setting up, you can still issue GoTos from a PC through Gemini.net.? Do you still get those Interrupted messages with the hand controller removed??? Maybe you already reported that it cannot be the hand controller... if so I apologize for asking again. Another related question: open your Gemini-1 and unscrew the 6 hexagon shaped top panel supports.? Lift out the board inside and inspect the back of that board. Do you see any corrosion or discoloration of the traces?? I am thinking that an intermittent in there could mimic a hand controller button press.?? You can clean any discoloration with alcohol on a cotton swab. Very best, and good luck, ? On Fri, Nov 3, 2017 at 6:50 AM, jfev5mnsvqiyzpq756wvokt55jve7sbg2esr5mip@... [Losmandy_users] <Losmandy_users@...> wrote: ? Hi!
Anybody got any ideas on this situation? I feel quite lost. Last night, I was imaging M33. I made a cold start, aligned with 3 stars with mount east of pier, then 1 star with mount west of pier. THen tried to slew to M31 with the computer - OK!. Tried M33 - Interrupted. So I slewed "manually", that is, used the motion control on the computer, until the scope was at M33. Did a plate solve - which syncs (does not update the model). After that, I could slew to M33 - that is, adjusting and centering M33 now worked! Why? If the model was not synced correctly - why did it not just slew to the "wrong" place (could not be much off, given how nicely it found M31) and then update on syncing? Why "Interrupted" at first attempt, but after sync it works?
See also my previous post with images of the time and location settings - anything wrong with them?
Any ideas, suggestions, are very warmly welcome. I'm on the verge of giving up on this and rob a bank to be able to upgrade to a Gemini 2.....
Magnus
--
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Re: GM-11 general lubrication
At 16:02 03-11-17, photon_trap@... [Losmandy_users] wrote:
The "Nuts" that the Alt and Az adjustment screws go through are brass or bronze (which is mostly brass)
That is true. The bolts that I am more concerned about are the ones that attach the mount to the HD stand and the locking screws. They are stainless steel, I think, and get fully tightened, whereas the adjustment screws are not tightened. My conern was that the fully tightened locking screws might seize up, if I am unlucky. David
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Re: G1 on G-11 refuses to go to bright stars
Dear Magnus,
Having read all of your misery on this... sorry to read the problem persists.
It is quite a mystery, and I can't recall anyone else reporting that type of "interrupted" trouble from a Gemini1 or 2 before.
I have only this idea for you to try...
Because you can "interrupt" a slew by pressing a hand controller button, I have wondered if there could be an intermittent contact/short in your hand controller buttons. The question is: do you still get this error with the hand controller removed (once you set up). After setting up, you can still issue GoTos from a PC through Gemini.net.? Do you still get those Interrupted messages with the hand controller removed??? Maybe you already reported that it cannot be the hand controller... if so I apologize for asking again.
Another related question: open your Gemini-1 and unscrew the 6 hexagon shaped top panel supports.? Lift out the board inside and inspect the back of that board. Do you see any corrosion or discoloration of the traces?? I am thinking that an intermittent in there could mimic a hand controller button press.?? You can clean any discoloration with alcohol on a cotton swab.
Very best, and good luck, Michael
?
Hi!
Anybody got any ideas on this situation? I feel quite lost. Last night, I was imaging M33. I made a cold start, aligned with 3 stars with mount east of pier, then 1 star with mount west of pier. THen tried to slew to M31 with the computer - OK!. Tried M33 - Interrupted. So I slewed "manually", that is, used the motion control on the computer, until the scope was at M33. Did a plate solve - which syncs (does not update the model). After that, I could slew to M33 - that is, adjusting and centering M33 now worked! Why? If the model was not synced correctly - why did it not just slew to the "wrong" place (could not be much off, given how nicely it found M31) and then update on syncing? Why "Interrupted" at first attempt, but after sync it works?
See also my previous post with images of the time and location settings - anything wrong with them?
Any ideas, suggestions, are very warmly welcome. I'm on the verge of giving up on this and rob a bank to be able to upgrade to a Gemini 2.....
Magnus
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Re: GM-11 general lubrication
The "Nuts" that the Alt and Az adjustment screws go through are brass or bronze (which is mostly brass)
J
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Michael Herman
photon_trap