AlexK

That's indeed an ideal trade situation. So just go grab it first, then post some images here, we'll assemble the Grand Consilium for that specimen in no time

Second to that. Totally sane price for that 10" used (~$750 brand new, but on backorder everywhere, so will be at $1000 soon no doubt). Just make sure it's not damaged internally or externally and has at least some stock accessories. If you can't visit seller in person to inspect it with the flashlight ask for clear images of anything they consider being a defect. And at least the primary's image in white light focused on its retainers (must be spotless even if dusty). Then you can try negotiating if you want.

Congrats, Michael! A decent light-gathering upgrade! The stiffness could be normal for it actually. This is not a Dobson scheme with feather-touch push/pull action you might be used to. It's a GoTo attempt on a particle boards fork. You supposed to drive it with buttons, not by your bare hands. The manual pointing operation is more like just an afterthought in such a design, so it's not like on a Dob and not like on a real Alt/Az fork mount. So to avoid any confusion I would try simply following the instruction manual step by step for automatic pointing (GoTo) first. That would also help troubleshooting the tracking issue, as most likely you have missed the proper mount alignment steps or lost it manipulating it manually in an unexpected way. Don't worry about your mechanical skills, it's still under warranty and on tech support, right? In fact, I would avoid any screwdriver tinkering with it for now, as that could void the former and make more expensive or lengthy the latter. Get to the support first (ditch it, and get a normal classic Dobson next <--- a joke, OK?). Disclaimer: All of the above is my personal opinion exclusively and leveraging my freedom of individual expression, you have rights to ignore acting on it in any way or interpret it in any way you see fit. (am I an ideal citizen now? )

Yeah, that Zeiss Coude is a true modern marvel of the optomechanics of 70-es. But by now, its mechanical base aging renders it less beneficial for the intended scientific tasks. E.g. the detectors miniaturization revolution outweighs the need of professional maintenance (expensive and time consuming). So it's being replaced at observatories to cheaper to own modern solutions with even more capabilities. Good for amateurs willing to take the job of restoring that technical wonder! It was especially awesome for imaging, photometry, spectroscopy, Sun observing (manual sketching, heavy H-alpha stacks). Anyone not aware of the Coude scheme: its focal plane is routed to the Polar axis by two flat mirrors, so the view is permanently and precisely fixed to the ground, thus your eye (or any other large and super heavy opto/mechanical and/or electronic instruments of the 70es or older) stays immobile and focused down to sub-microns while you move the other end of the optical axis around the sky: Though at our youth observatory it was idling for years in a row due to mechanical issues started to pop up here and there due to the lack of scheduled professional mechanical maintenance. I believe by now it's just sitting in the storage partially disassembled.

Re Dobson cooling. It should not be too much of an issue on the Islands as the temperature swipes are not that drastic there. I see it's like 20C to 10C (day/night) in the summer. So with the cooler fan it should be like 20 min. If that's still seems like a serious problem for your flow you don't have to wait, mod your OTA with the surface layer blow fan(s) and/or front duct ring. Folks swear that running it when observing is fixing the problem nearly instantly. Re atmospheric conditions and the large aperture. That's true, smallish aperture will show a smallish planetary disk kind of more neatly and for kinda longer. But what's the goal? Enjoy the neatness or see tough details? With my 12" I saw fine details in individual Jupiter belts clouds, as well as streams around the GRS! Yes for a second or two in like 30 minutes of manually guiding it uninterrupted at 640x, but that was truly striking, spacecraft flyby like experience, enough to forget about refractors and GEMs forever! Re GoTo. Better skip that doubtful feature on a furniture-particle-board fork mount which is typical for commercial 12" GoTo reflectors. It's never 100% reliable and a chore to use immediately and to service it over time. Needless to say it's rendering all benefits of the Dobsonian design to zero. So I believe it's just a dead(ly) weight . Yes, it still has certain appeal for a knowledgeable (or warned) newbie because of the tracking possibility though. Especially having in mind that the real Dobsonian mount (which is a breeze to guide manually) is a really rare find nowadays anyway as every China engineer has "innovative" "improvements" ideas of their own (including that GoTo gimmick). But still, for less or comparable money you can have an direct-focus-imaging-capable tracking added eventually with the EQ Platform (DIY, custom order, or even OTS). Wooden GoTo mount can't help even with the piggyback imaging. The trivial star hopping is way more reliable at pointing than that GoTo as soon as you get a properly designed for that flow digital star chart on a handheld device and practice with it a bit. And to give you a perspective: the manual telescopes pointing revolution, giving you a nearly effortless 100% reliable pointing possibility is just around the corner (I might be even not the first announcing it).

I spent several years observing hands on with the professional high end 150mm Zeiss Coude refractor and with the high end Russian long refractor AVR-3 (also 150mm). Both stationary installed on their stock high-end motorized equatorial piers under the sliding roof of the local youth astronomy club's observatory. I can tell you without a single doubt: views with my current very-average-optics 12" Dob are very long way better in every regard on planets and DSOs (weather permitting)...

Unless that would also involve our Sun turning into the Black Hole (what an astronomer's paradise is that! See a BH and die!), I will be still enjoying my ODA (Observer's Digital Assistant, a.k.a. dedicated astronomy smartphone) which objects database equals in ink and paper (required to print them all) to several tons of paper charts. Because I have a briefcase-size-folding 150 Watt solar panel (works well enough even in the overcast to charge a phone). That's the last resort after I have exhausted my 500 watt/hours power brick, 4 x 3-8 Amp/Hours pocket 5V power banks, and the ODA spare battery (yes it's still has a replaceable battery as that was the ODA selection goal!), not to mention two smaller solar panels for hiking and EDC, my in-car dynamo, and the small 1 Kwh gas generator (Oh, no! That one is out as it will power my fridge with cold beer)... Nope, I'm still good without the planisphere during the apocalypse (a.k.a. TEOTWAWKI) 😂

Cheers back NGC 1502! That's right. The Astroscan is the observing ergonomics high end of all times! And definitely a keeper! I got it from a fellow colleague amateur astronomer for free specifically for my son some years ago. Because this marvel is not for sale! Only for giving! But I considering it mine too as I play with it more than him Care for it well! Yours is even more unique! And it looks like manufacturers are not rushing a new model into production anytime soon for some weird reason By the way, you can find several mods and outfits I've done to/with my Astroscan on my blog. I have collimated the secondary and primary by shimming as well myself. It gives amazing views with the 9mm WO 101 AFOV! To stay on the subject: I do love planispheres. When I was a kid (8-18 y/o) I had a 2 meters in diameter, 7 colors printed press, laminated, DIY cardboard pieces backed, classic planisphere in Russian mounted by my father on the concrete anchor in the wall of my room. For the horizon overlay I've made a huge wire ring hanging down from that same screw (in later years back then I have added the overlay wire following my local urban horizon line carefully modeled over the course of several observing nights bending it between matching stars). I've made hourly marks from two old broken wall clocks (brass digits) on separate plaques glued to the wall around the chart's disk, azimuth points were made from red copper wire rings on the main aluminum wire... Needless to say that after literally living between stars for so long in my childhood I now know constellations' stars very well. If you point to any star in the sky, I can immediately tell its name/greek letter/flamsteed number, even if it's barely visible between trees. Or I always immediately noticing any "extra" stars (being that a planet, comet, an artificial airborne/space light source). Or, when I see any movie, or a piece of art (e.g. in computer games) depicting some starry sky, I can immediately tell if that's "our sky" or some alien/fantasy one because constellations stars are so obvious and familiar... But I would never even consider a planisphere as an observer's tool. Learning, demoing, studying - OK, but at the eyepiece I strongly prefer a handheld eyepiece view chart. EDIT: Simple orienting? Nah. Good digital chart has several much more effective basic orienting methods starting from mirroring the 180 degrees view projection, which makes the screen working as a "star compass" with constellations down on the table matching directions to real constellations in the sky. all the way to the StarSense Explorer software, actually "seeing" where the phone is pointing between stars and telling you where to move the telescope...

How so? You have to use a bright enough flashlight to see its large white low contrast blinding beauty On a side note, it's easy enough to remember all these ~100 black (or blue what have you) dots and skip that redundant step for good while planning. A good star chart will show you what's up and what's not anyway.

The above double-sided one is a way better design compared to the classic one. First of, it has much less distortions. Clean to comprehend, and even has lines teaching you the bright constellations stars finding with pointing figures. E.g. Arcturus is on the extension of the UMa "handle". Regarding planets not charted, Louis, you supposed to watch for the ecliptics line on that chart (dashed). Planets are bright stars. So if you follow the ecliptic line on the sky and stumble upon a bright star not charted on the planisphere, that's a planet (or an UFO). You can learn distinguishing outer planets by their color. While Venus and Mercury are day and night in brightness and always close to the Sun. Also, there is a common misconception that planets do not blink compared to stars, but that's referring way back into the days with no industrial pollution to speak about much.

Planisphere is like a wall calendar. But if you don't know constellations, not aware of sphere to surface projections, don't know what the LAT, ST, LMT, UT, LST means, it's nearly useless in the field. But you can use it to learn all of the above. And even get an inner sense of the astronomy time building up gradually. Just hang it on the wall (see the hole in the corner) and move it like every week. Then memorize what's displayed on it, i.e. at around 10pm LMT, when passing by on your daily route. The wall in front of the toilet is a good learning place for it as well 🤣 Just by the way, here is my pocket planisphere which is always with me (in the center) I watch it at midnight LMT:

C'mon folks! A stepper's "back flush" current is rather miniscule and will be grounded by the driving MOSFET anyway (the controller is separated from "gentle CPU circuits" by the high power driver). I have my printer for 7 years and moving X/Y 250mm wide back an forth all the time. No issues. Never heard about anything drastic like that either. Urban legends. Disconnecting your motors you are just reducing connector's lifespan and possibly eventually crack the PCB from mechanical stress too.

Hmm, like what you mean? There is an exhaustive database of ~2000 OCs in existence. What else an observer might desire above that? The "Best 100 Review"?

Awesome! Please keep it coming!

Kinda unclear what exactly you have invented here without the full context 🤔 My guess is that you have used that MSM rotator arm-head to place that orange block precisely against your forehead when at the eyepieces for better binos stability? That would work if the back of your head is resting on something fixed to the ground as well (a chair's back). If not, a very good cushioning is a must to prevent view shaking. Not just to feel it better on the skin. See the rubber eyeguards? They are not only for the side light cut off but mostly to prevent exact that problem at the high magnification when they are resting on your eye sockets bone. So, instead of a thick or long cushioning piece there I'd suggest 3D printing a simple scissors spring in the middle. It will be damping head shaking much more efficiently. Though it's main benefit is to unload these large binos weight on your face, not to improve the view stability directly. However, the latter will be surely benefited from your muscles tiring slower with that attachment. By the way, when I had a similar idea (head-mounted 2x54 monocular) I've got my head 3D scanned professionally 😇 So now I can design such "bionic" things simply subtracting that head shape from the 3D model. Try that! (just make sure your hairstyle is not getting into the way, I regret I didn't cut them shorter back then 🤦‍♂️).