Re: [TAC] For Sale: Obsession 18" Telescope

[Tim Lorz]

Hi Mitch - 

Quick question - your scope is a manual dob, right? or do you have tracking in it?

- Tim

On Mon, Oct 20, 2025 at 10:00 AM mitchroberts2530 <mitchrob...@gmail.com> wrote:

The Obsession 18” x 2-inch-thick mirror

The Feather touch by Starlight Instruments

Wheelbarrow handles

Ripstop Nylon light shroud

Truss Poles with storage bag

 

Tele-Vue Eyepieces: 40mm, 32mm, 19mm, 7mm and 2x Barlow

Lumicon: H-Beta, UHC, Deep Sky, Oxygen-III, and Blue #80A, Green #85, Red #25, Yellow #15 and Moon Filters

Telrad Reflex Sight

Orion 9x50mm Correct-Image Right-Angle

Kendrick Astro Instruments Barlow Laser Collimator 2" Barrel for line up the mirrors

 

Local pick up only 95051 (Santa Clara, CA). You will need a minivan or SUVs for transport.

 

Ask for $7,000.00 or OBO.

Mitch

mcr...@att.net

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[Mitch Roberts]

There have the tracking devices mounted on it, but I don’t use it. 

On Mon, Oct 20, 2025 at 1:10 PM Mitch Roberts <mitchrob...@gmail.com> wrote:

I used it with manual.

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[Tim Lorz]

Hi Mitch - thanks for the response. Does the tracking work on it, even though you don't use it?

Thanks

Tim

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[Mitch Roberts]

Hi Tim,

It should work with tracking if you have a tracking device. I don’t have a separate tracking device since it was already built in when I bought it.

Mitch

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[John Pierce]

On Mon, Oct 20, 2025 at 3:43 PM Mitch Roberts <mitchrob...@gmail.com> wrote:

It should work with tracking if you have a tracking device. I don’t have a separate tracking device since it was already built in when I bought it.

On Mon, Oct 20, 2025 at 1:30 PM Tim Lorz <tim....@gmail.com> wrote:

Hi Mitch - thanks for the response. Does the tracking work on it, even though you don't use it?

looks like it just has the encoders, not motor drive.    and there's no controller for the encoders so you would need a 'push to' system to use them. 

[Mitch Roberts]

Yes, that’s correct.  I used it as manual.  I don’t have a controller for it.

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[Joe Acosta]

It is possible to convert the scope to goto.  Just need stepper motors and controller board. Certain 3d printer boards are known to work with onstep https://onstep.groups.io/g/main/wiki/4414

Joe

[John Pierce]

In my not so humble opinion, an Obsession Classic is just about perfect as a manual dobson, it moves smooth as silk and stays where you nudge it with no overshoot or wobble, at least until you get up around 500X...  adding all the motors and stuff greatly increases the complexity, and also makes the whole thing a lot more fragile for transport etc.   I almost never had problems finding targets using just the Telrad in conjunction with charts that had telrad reticles, or tablet based charts with telrad circles projected, then drilling in with a medium low power eyepiece (frequently a 82 degree 18mm, which gave about 140X on the 20" f/5 and a bit over a 1/2 degree AFOV)