Re: tracking drift 15" classic AN/SC
Well, I was going to tell you to contact Gary at StellarCAT, but I just looked and his web site is down. Don't know what's going on. I will say that he has ALWAYS been very responsive and helpful - I've never an an issue with either the SC or AN that he was unable to help me with.
Mark
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tracking drift 15" classic AN/SC
I've had 4 scopes with AN/SC (3 Obsessions) and never had this happen before. GoTos are spot on, but then the image drifts up in the EP fairly rapidly, almost as if it is not tracking on that axis. But the AN reads how much off it is and GoTo puts the image right back in the FoV. Not a big problem when just sight seeing, but I like to sketch and having to keep adjusting the aim to center the image while drawing is a pain. Plus it will be a problem once the pandemic panic is over and I can start outreach star parties again. Any suggestions on what is wrong - and how to correct it will be much appreciated.
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Re: New Obsession 18 Classic setup.
Hi Bob,
I forgot to add that you have to secure the way the secondary holder is fixed in the secondary spider. If this is not tighten enough you will have some flexure with altitude and the secondary will move more significantly than this is tighten firmly. You can imagine that this is true for spider in UTA and also truss tube in UTA. If you have some lag somewhere it will result in flexure with altitude and you collimation will show this flexure as the secondary moves.
Once again, this is just some exercises you can experiment in day light to fully enjoy this scope at night.
¹ó°ù¨¦»å¨¦°ù¾±³¦
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Re: New Obsession 18 Classic setup.
Hi Bob,
I have a classic 15 and UC22. First I am very astonished when you say that the collimation changes with rotation. There is something wrong or strange in your setup as I don't remember having read (former group on yahoo) of anybody reporting this kind of issue. On my own the collimation is highly stable in rotation (azimuth changes).
It is true that it is a little bit sensitive in elevation (altitude changes). To counter this little issue I first chose to secure the truss tube in the wooden blocks. You don't have to tighten like crazy but too smooth will result in more flexure of the truss tube in relation with the mirror box. Second I always choose to collimate at the average altitude between the lowest altitude of observation (say 25¡ã that is already very low to have a good path to observe) and 90 so something like 25+35=60¡ã altitude. Yes I can see that it moves a little bit (the triangle in the middle of the circle of my cheshire) but this is marginal.
And I have read that this issue is more significant for UC18 as this one has the focuser in the middle of an arc of the single annular UTA between two support points with the truss tubes (6 instead of 8 for the UC18). I do not have this issue with the UC22 where the focuser is very close of a connection point of the UTA with the truss tubes.
Clear skies, ¹ó°ù¨¦»å¨¦°ù¾±³¦
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Re: New Obsession 18 Classic setup.
The camlocks just need to be lightly snug. Its easy to over tighten them, and then it becomes difficult to pry the wedge out when you break it down, and it damages the aluminum truss poles.
--
Tim
15" obsession classic
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Re: New Obsession 18 Classic setup.
I have a 15UC and find if I collimate at about a 45 degree angle I have no problems. It is a good idea to collimate at an angle that is close to the angle you will mostly be using it at.? I do not do any astrophotography and have been very happy.
You want to have things hand tight so it is secure and solid but not so tight that you bend or break something.
Chris?
On Wed, Mar 3, 2021 at 4:35 PM bob414 < bob414@...> wrote: Thanks for every ones help.? We now have a beautiful 18' Obsession Classic.? That I feel safe to operate.
New Question.
We have used both a laser and Cheshire collimation tools to collimate the scope.? We notice that the collimation changes significantly with the position of the scope, both rotation and elevation.? Is there anything to look at specifically to minimize these collimation changes.
How tight is to tight on the Camlocks, etc?
Bob
? ?
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Re: New Obsession 18 Classic setup.
Thanks for every ones help.? We now have a beautiful 18' Obsession Classic.? That I feel safe to operate.
New Question.
We have used both a laser and Cheshire collimation tools to collimate the scope.? We notice that the collimation changes significantly with the position of the scope, both rotation and elevation.? Is there anything to look at specifically to minimize these collimation changes.
How tight is to tight on the Camlocks, etc?
Bob
? ?
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Markless Astronomics Website
The website is up!? Sorry for the inconvenience. ? ? Best regards, ? Charlie Starks Markless? Astronomics Accessories for Obsession Telescopes and other Big Dobs ? ?
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Re: New Obsession 18 Classic setup.
Thank you very much, the manual will really help.? There were a few things that the manual really cleared up.? This will allow us to operate the scope safely and properly. ? Bob ?
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From: [email protected] < [email protected]> On Behalf Of ¹ó°ù¨¦»å¨¦°ù¾±³¦ Ruciak Sent: Sunday, February 14, 2021 12:43 PM To: [email protected]Subject: Re: [ObsessionUsers] New Obsession 18 Classic setup. ? Hi Bob,
I own both a classic 15 and UC22. First of all, what Mark said is right, the primary are suspended with a kevlar string. I scanned and attached my owner manual. You will have to setup the length once. According to my experience, when you move the scope (traveling to your observation site) the mirror will probably slide a little and the first step to collimate is to recenter it laterally. I do it from the back with a soft piece of cardboard that has to fit on each side of the mirror in the mirror box to center it.
To really enjoy it you just need to go through the same checklist each time you mount it and prepare it but these are super telescopes. For example, I numbered the truss pole to be sure to put the same tube each time in the same wooden block to retrieve collimation as close as possible and ease it. Another trick (as I am observing alone), I prepare a picture covered with plastic indicating how the triangle I use for collimation moves in the cheshire according the the collimation screws at the back to I don't have to think when I go back and forth from the cheshire to the collimation screws to adjust collimation (especially for the 22).
Enjoy,
clear skies, Frederic
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Re: New Obsession 18 Classic setup.
Hi Bob,
I own both a classic 15 and UC22. First of all, what Mark said is right, the primary are suspended with a kevlar string. I scanned and attached my owner manual. You will have to setup the length once. According to my experience, when you move the scope (traveling to your observation site) the mirror will probably slide a little and the first step to collimate is to recenter it laterally. I do it from the back with a soft piece of cardboard that has to fit on each side of the mirror in the mirror box to center it.
To really enjoy it you just need to go through the same checklist each time you mount it and prepare it but these are super telescopes. For example, I numbered the truss pole to be sure to put the same tube each time in the same wooden block to retrieve collimation as close as possible and ease it. Another trick (as I am observing alone), I prepare a picture covered with plastic indicating how the triangle I use for collimation moves in the cheshire according the the collimation screws at the back to I don't have to think when I go back and forth from the cheshire to the collimation screws to adjust collimation (especially for the 22).
Enjoy,
clear skies, Frederic
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Re: Powering iPad / netbook from SC power rail & battery questions
Greg -
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Yes, I have a full charging system for my SkySafari iPad installed on my ServoCAT equipped Tectron. My system includes the Markless Tablet Stalk.
?
So I have a cable plugged into one port on the 12V PowerRail that runs to an inline fuse holder (a 2A fuse is sufficient) then on to a 12VDC to USB port adapter. This stuff is all down in the bottom of the rocker with the rest of the SC gear and cables. A short USB cable plugs into the USB port adapter and then runs out the hole on the side of the rocker and plugs into the USB port on the base of the Stalk. The Stalk _must_ be ordered with the USB cable option... At the top end of the USB cable that is integral to the Stalk, I have an USB A to Micro-USB adapter and then a Micro-USB to Lightning plug adapter that connects to the iPad. It is a slick system and I never have to worry about my iPAD crapping out late at night...
I tried using a knockoff Micro-USB to Lightning adapter from Amazon but it refused to work. Apparently there's a tiny chip on the more costly Apple Micro-USB to Lightning adapter that handshakes with the iPad charging system.
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Ping me offline if you'd like more details.
?
Gordon
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gpegue at comcast dot net
On 02/09/2021 10:12 AM busy_sky_guy via groups.io <busy_sky_guy@...> wrote:
?
?
I recently attached a Skyfi wireless unit to my Obsession SC/AN and bought SkySafari6 Pro which can be run from a PC using an android app emulator like Bluestacks, or from an iOs device like an iPad/iPhone/Macbook.? It is fun to see where the scope is pointing to real time on the planetarium program as the scope slews between targets, I am thinking of getting a Tablet stalk from Markless to keep it on the scope during observing sessions, placed next to my DSC stalk.? I think that I would be limited by the internal battery run time of the iPad, and I would prefer to have power to the iPad routed through the scope power system so the scope can rotate in AZ without any wires getting tangled. Seems silly to mount a separate battery for the iPad when the scope has a power distribution system already installed.
1. Has anyone run an iPad or PC off a deep-cycle or similar battery from the Obsession power rail??
2. Should I be looking for a cigarette-lighter plug to lightning adapter, and replace the cigarette plug adapter with terminals that would fit on the power rails?
3. Should I be adding an in-line fuse?
4. How does a dummy like me know which wire is positive?
At 15 years, my old deep cycle battery (55 amp hour Optima D34 yellow top, about 45 lbs) is on its last legs and needs replacement, I am thinking of building a battery box
but with different ports.
1. Does anyone have a DIY battery box plan that they like?
2. Are people using lead-acid deep cycle or lithium iron phosphate (LiFePO4) batteries to power their scope?
3. Do people not prefer to mess around, and just buy an off the shelf solution
from Jackery ($1K for about 46 amp hours)?
Thanks
Greg?
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Re: New Obsession 18 Classic setup.
Unfortuantely, no. Front of mirror. So put the scope together, weight it and move it to horizontal. Then tighten the nuts on the tops of the standoffs. That way you won't be over the mirror.
Mark
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Re: New Obsession 18 Classic setup.
How do you tighten the mirror fingers?? Is this done from the bottom of the primary mirror box?? I do not like the idea of working on the mirror side, in case of dropping tools.
Bob
Is there a manual, youtube, picture etc. showing the procedure?
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Re: New Obsession 18 Classic setup.
Bob:
As a classic 18 owner myself, I fully understand your questions! Not a big issue on either of them. The primary is supposed to have a kevlar sling that goes around the edge of the mirror, with adjustable pins on each side, at what is the top of the mirror when the scope is horizontal. They are reachable from the bottom of the box to adjust. You want the mirror to be suspended above the bottom pin when the scope is horizontal.
The fingers that point out over the mirror are to keep it from falling out of the mount, and should be tightened (not TIGHT, just tight so they don't turn) to keep them out over the mirror. Trust me, they do NOT affect your view!
That said, my experience with Obsession (I've had mine - bought used - for 15 years now, and have found Dave K to be incredibly helpful over the years - never fear to reach out to him!
Mark
Obsession 18 F4.5 Classic - S/N 1045
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New Obsession 18 Classic setup.
A past member's family just donated a 18" classic to our club.? I have some experience on truss tube dobs, but some things on this scope gives me pause.
? ?1.? The primary mirror just loosely sits in box, has side to side movement, about 1/4 inch.?
? ?2.? There are 3 fingers, rubber sleeved, on the front of the primary mirror, one is firmly contacting mirror, the other two just spin around in front of the mirror.
We were able to get the scope close to collimated, views were great!? But with these problems, i know that it is just a temporary collimation.
Is there a manual, that shows the correct procedures for correcting this problems.
Any help is greatly appreciated.
Bob
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Re: Powering iPad / netbook from SC power rail & battery questions
That is clever as all get out! I left CN years ago, thanks for sharing that. <RE>
On Tue, Feb 9, 2021 at 12:12 PM busy_sky_guy via <busy_sky_guy= [email protected]> wrote: I recently attached a Skyfi wireless unit to my Obsession SC/AN and bought SkySafari6 Pro which can be run from a PC using an android app emulator like Bluestacks, or from an iOs device like an iPad/iPhone/Macbook.? It is fun to see where the scope is pointing to real time on the planetarium program as the scope slews between targets, I am thinking of getting a Tablet stalk from Markless to keep it on the scope during observing sessions, placed next to my DSC stalk.? I think that I would be limited by the internal battery run time of the iPad, and I would prefer to have power to the iPad routed through the scope power system so the scope can rotate in AZ without any wires getting tangled. Seems silly to mount a separate battery for the iPad when the scope has a power distribution system already installed.
1. Has anyone run an iPad or PC off a deep-cycle or similar battery from the Obsession power rail??
2. Should I be looking for a cigarette-lighter plug to lightning adapter, and replace the cigarette plug adapter with terminals that would fit on the power rails?
3. Should I be adding an in-line fuse?
4. How does a dummy like me know which wire is positive?
At 15 years, my old deep cycle battery (55 amp hour Optima D34 yellow top, about 45 lbs) is on its last legs and needs replacement, I am thinking of building a battery box but with different ports.
1. Does anyone have a DIY battery box plan that they like?
2. Are people using lead-acid deep cycle or lithium iron phosphate (LiFePO4) batteries to power their scope?
3. Do people not prefer to mess around, and just buy an off the shelf solution from Jackery ($1K for about 46 amp hours)?
Thanks
Greg?
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Powering iPad / netbook from SC power rail & battery questions
I recently attached a Skyfi wireless unit to my Obsession SC/AN and bought SkySafari6 Pro which can be run from a PC using an android app emulator like Bluestacks, or from an iOs device like an iPad/iPhone/Macbook.? It is fun to see where the scope is pointing to real time on the planetarium program as the scope slews between targets, I am thinking of getting a Tablet stalk from Markless to keep it on the scope during observing sessions, placed next to my DSC stalk.? I think that I would be limited by the internal battery run time of the iPad, and I would prefer to have power to the iPad routed through the scope power system so the scope can rotate in AZ without any wires getting tangled. Seems silly to mount a separate battery for the iPad when the scope has a power distribution system already installed.
1. Has anyone run an iPad or PC off a deep-cycle or similar battery from the Obsession power rail??
2. Should I be looking for a cigarette-lighter plug to lightning adapter, and replace the cigarette plug adapter with terminals that would fit on the power rails?
3. Should I be adding an in-line fuse?
4. How does a dummy like me know which wire is positive?
At 15 years, my old deep cycle battery (55 amp hour Optima D34 yellow top, about 45 lbs) is on its last legs and needs replacement, I am thinking of building a battery box but with different ports.
1. Does anyone have a DIY battery box plan that they like?
2. Are people using lead-acid deep cycle or lithium iron phosphate (LiFePO4) batteries to power their scope?
3. Do people not prefer to mess around, and just buy an off the shelf solution from Jackery ($1K for about 46 amp hours)?
Thanks
Greg?
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Re: ==> ready for X-Mas observing nights from Italy¡ !!!
You could also chase Jupiter and Saturn during daylight hours!? Looking at the photo, I am guessing you could use the roof of the house to the West to block the Sun and catch the gas giants.
Regards,
Frank Nowatzke
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Re: ==> ready for X-Mas observing nights from Italy¡ !!!
Very Nice!!? Enjoy the views!
Beware of the "new telescope curse1"? Those who obtain a new telescope must suffer through many cloudy nights prior to using the scope.
Ciao, Frank Nowatzke
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Inviato da per Windows 10
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==> ready for X-Mas observing nights from Italy¡ !!!
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Inviato da per Windows 10
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¹ó°ù¨¦»å¨¦°ù¾±³¦ Ruciak
Christine Zeltner
Frank Nowatzke