开云体育

Wow! That's the most new users I've seen come onto this group in one pass since it was created!

Charlie: If I'd known you weren't here I'd have told you about it last year when you helped me get my scope updated. Welcome!

Mark

开云体育

Hello all, again,

In response to Roger Greenwood's suggestion, here is the post that I placed on the old Obsession Yahoo Group today (July 30, 2020).? Thank you for your indulgence!

Greetings, Obsession Users,

?

Greetings!? It has been over a couples of years since I sent a general note on this group and I am not even sure if people are still receiving these emails [on the old Yahoo Group], but every year there are new Obsession owners who may not be aware of some of the ways to accessorize their new telescopes.? So please excuse this brief intrusion.

?

Most of the basic kits are still available, like the Fan Connection & Switch Kits (which preserve a switch on your Power Rail), and the Spider Wiring Kit to reduce your dependence on 9V batteries to power the Dew Guard on the secondary mirror.? There are wiring kits for scopes without a ServoCAT and PGB, and wiring kits to get power transferred up to the UTA.? And, of course, we still have the DSC Stalk for Argo Navis as well as one with a different shelf for the Nexus DSC.? The Nexus Stalk is not on the website, so just ask about it when you email me.? The Tablet Stalk is gaining in popularity, as well.? After all, you need a place to put down the Tablet!? There’s even a page just for UCs and a page showing a typical truss tube Dob’s electrical diagram and typical DC current requirements. ?And, many more items.?

?

Just one thing.? My website hasn’t been updated since about 2015, so the prices are a little outdated.? When you inquire, I will send an up to date quotation, so that you can decide.

?

Looking forward to meeting your Obsession telescope needs.? And now is a good time to get them before the fall rush!

?

Best regards,

?

Charlie Starks

Markless? Astronomics

Accessories for Obsession Telescopes

Obsession 20 #467

Late reply, I upgraded to 30K encoders and they work well - if using Argo Navis you will need to adjust the time on / time off setting under encoders. I got mine from Dave K a while ago.

Greg

开云体育

Hi,
for the very few of us who have not yet ran through this procedure, I warmly recommend to do so.
The result is no more mechanical constraint on the alt sensor when the scope is moved in altitude and a more precise pointing in alt.
Thanks again to Scott Tannehill who wrote the "how to".
For those having a UC scope and have not decided like me to chose for one piece alt bearing and fixed installation of the alt sensor, I also recommend this very basic tool:
It's a long narrow wood stick with following characteristics
-at one end there is a small shoulder (making a L with the length of the wook stick) intended to be placed at the sliding surface of the alt bearing
-at the other end there is a hole with the exact same diameter as the alt sensor axis
-the length of the wood stick is such that the distance between the center of the hole and the surface of the shoulder is exactly the radius of the the alt bearing.
-use it the way described in the attachment

I bought the tool to some guy on the web and I discovered that it was so simple to build and use that I should have had the idea myself.
The way to use it is enclosed. I used it before choosing to move to a fixed alt sensor installation and it works perfectly well (I checked it the Scott Tannehill method)
Hope this helps.
Frederic

Hi Everyone,

I am glad to see that the Obsession User group is back up and operating. I use to love the old site it was great and had a lot of good information. My main telescope i use is he Obsession 15 classic I have had since 2006. i am looking to replace the DSC encoders the old 8192 encoders. Can any tell what brand or type they are and what would be a good replacement without having to modify the scope axis. Any help would be greatly appreciate.


David Brown from Central Mass.

In the old archives, there were two PDFs describing how to fix the collimation drift on UC:
1. someone had some kind of re-enforcing aluminum ring for the UTA
2. someone else had used some kind of carbon fibre rods to stabilize the focuser

If anyone has those two documents, can they please re-post?

Thanks
Pawan?

My elderly 43 pound D34 Optima yellow top C20 55 amp hour battery is failing to hold a charge long enough for an extended observing session with my Obsession 18 classic with SC/AN,?I have a powered ground board on my scope.?At the end of a session AN/SC was not behaving normally, and the battery was under 8V.?

I thought it would be helpful to ask what deep cycle batteries those with a setup similar to mine use (brand and C20 amp hour capacity). I use an AGM battery (Absorbed Glass Mat) as my understanding is that type of battery is better than a lead acid battery for deep discharge, and it is cheaper than a gel battery. An identical replacement battery is around $250.

I just haul my battery out into the field for use, it is not in an enclosure.? I have terminals on the battery which are attached to a fused power cable, then which goes into the ground board. Pro tip: attach your cable permanently to the battery terminals rather than using spring loaded clamps which you attach and detach for each observing session: if you get the polarity wrong be prepared to spend a lot of time replacing fuses. Ask me how I know this!

I thought it might be nice to have a power supply with a built in voltmeter so I could know the battery charge without having to pull out a multimeter. I have seen kits online for battery boxes for batteries that include cigarette style plugs, built in USB outlets and such.? Most are for applications like ice fishing and so use small 7 amp hour batteries, my power needs are likely greater if the scope is slewing through the night and running dewheaters for the secondary mirror, telrad and finderscope.? Does anyone use such an enclosure or built a battery box kit successfully?

I like the fact I can run my scope for at least a few days without recharging with the D34 battery, but the battery is a little awkward to lug long distances as it weight 43 pounds and I carry it with a small strap that crosses the top of the battery. Optima has smaller battery sizes such as D35 which has 48 amp hours and weighs 36 pounds, or D51R which has 38 amp hours and weighs 26 pounds.

What battery size do those of you with SC/AN and multiple dewheaters use?

Does anyone use a heavy battery mounted to a cart for easier transport?

I mainly use the scope to home, where there is a power source available.

Thanks!

Greg



I enjoy the capacity of the 55 AH battery, but it is a b

Hello,

This email message is a notification to let you know that the following files have been uploaded to the Files area of the [email protected] group.

• /Version 4.0 Locating ALT axis on Dobsonian.ppt

Uploaded By: busy_sky_guy <busy_sky_guy@...>

Description:
Locating Alt axis on a Dobsonian v4.0 Scott Tannehill

Cheers,
The Groups.io Team

开云体育

开云体育

Hello Group,

开云体育

开云体育

Long time lurker here, heartbroken about the lost posts - it was a treasure trove of information for new users or current users with a question.

I have a few files that I downloaded from the old yahoo site the I could upload to the new group site (e.g. Scott Tannehill's excellent "locating the alt axis on a dobsonian").??

Does someone want to make some kind of coherent folder structure where appropriate files could be placed, so people could find them easier (e.g. "collimation", "mirror cooling", "eyepieces", "Argo Navis", "ServoCAT", "Obsession astrophotography" etc) specific to Obsession scopes and their clones so people can upload documents on topics they have found useful? I realize AN / SC have their own forums, but I have found info which is tailored to dobs / obsession to be more useful and easily applied than more generic instructions

I have made a beginner's user guide for the AN / SC combo for Obsession users - I could not wrap my head around all the features in Gary K's manual for the AN and made my own (I use a flowchart method for a lot of the AN stuff), along with a custom catalog with stars spread somewhat evenly across the sky to make sampling stars for a pointing model easier (I always had to consult a star chart for mode tour, and some of Gary's common star names are different from those in some atlases, and could never seem to do it efficiently).? Maybe I could upload after I clean it up a bit, then we could change it into a wiki that users can edit.

Glad to see the forum re-awakening, we have a lot of people with experience and perhaps we can rebuild some of the more useful information we have lost.

Greg
18" Classic AN/SC

I forgot all about the comfort factor. I can drape myself on this ladder and be very comfortable for a long time, until the rotation of the Earth forces me to reposition the ladder. Attached is a picture of me on the tallest orchard ladder that I am aware of in the amateur astronomy community, with the eyepiece at zenith being in the 18-19 foot range... somewhere down in Texas... aperture being in the 48" range... and feeling zero anxiety and 100% stability... gotta love the orchard ladder...
--
Paul Alsing
25" f/5 Classic Obsession

Roger,
I went to the three legged ladder about 15 years ago. I haven't regretted it. I elected for an Electricians type. It is a few pounds heavier than the aluminium but available locally. The ladder had 12" pitch steps which I added in intermediate steps cannibalizing steps from a donor ladder of similar species. Besides stability another advantage of the 3 legged design is you can turn the ladder about 60 degrees to the scope allowing you to kind lean against the ladder resting your torso and getting very comfortable. Being comfortable will allow better concentration at at the eyepiece. Thus more difficult objects.
Bob Rose
22UC

--
Paul Alsing
25" f/5 Classic Obsession