Skywatcher EQM 35 Pro New Owner

[theropod]

I’ve been wanting a goto equatorial mount for a couple years now, and I had my sights set on an iOptron CEM25P. Up until now my main interests has centered on meteor falls, but occasionally I’ve peeked at Andromeda, the great nebula in Orion, and yearned for something beyond a ball head and fighting every inch of the way. The pandemic, as we all know, has messed up the supply chain for all things astronomy related, and my first choice of mounts just wasn’t to be had. My procrastination, for who knows what reason, forced me to look for alternatives. I pulled the trigger now because of my health issues forced me to face the fact that I’m not getting any younger, and if I want to do this astronomy thing half way seriously I better get to it.

I did spend a good amount of time researching this little mount, and it seems it will fill my needs quite well. I’m currently the owner of a little Celestron C-90 Mak, and the mount should handle that pipsqueak scope easily. The Skywatcher should leave me some overhead for a larger scope in the future, as well as a guide scope and imaging camera.

I understand that the drive train may need tweaking, and a little tuning here and there to get the mount to peak performance, but that’s down the road a ways. I’ve already mounted and balanced the C-90, and I’m confident the mount is more than capable. It is a little cheap of Skywatcher to not include a power supply with the mount, but I have a spare 12 volt battery that should work well enough. I’m suspect of the cigarette lighter type plug, and may rig up another male barrel jack that has a direct connection to the battery. I also find the lack of illumination of the polar scope somewhat cheap. My iOptron SkyTracker pro, a simple single axis tracker, has this feature. Yes, I know I can shine a torch into the objective to see the reticle, but adding a tiny red LED was just too much trouble?

I need to find/buy a reticule eyepiece for the C-90, but that can wait until I’m ready to start imaging. I’m nowhere near ready for that, and will start off just observing. I can probably get “close enough” by spitballing the alignment stars for now.

All in all I’m pleased, but I have not applied power to the mount (I just unboxed and assembled it this morning). I’m going to read the provided literature a couple times more and make sure I am not screwing up something critical.

Any advice one would care to offer I’m encouraging you to offer it!

For all those in the lower Mississippi valley I apologize in advance for the weeks of thick cloud cover that’s about to set in.

[Seelive]

There were a couple of things that needed sorting on my mount - the declination axis was far too stiff and the polar scope graticule was completely out of alignment. Fortunately, both were easily fixed and I've been happy with the mount since I purchased it just over a year ago. It's just a shame that the quality control during manufacture didn't sort these issues prior to shipping.

[theropod]

I took a look through my polar scope, and can’t believe how far off it is! I set the altitude to match my location (approximately), leveled the mount and the reticule is at least 10° tilted to the west.

Do I loosen that tiny socket hex/allen key as shown below, twist the scope and snug it back down when it’s where I want it? Nothing in the manual about this.

Am I correct in thinking that if a level the mount and hang a plumb string I can get the up/down crosshairs to match I’ll be pretty close?

EDIT: I just watched a video and now understand that there are two other such socket/allen screws, and how to GRADUALLY bring the crosshairs into the correct position.

Edited October 24, 2020 by theropod
clarity

[theropod]

Does anyone know what size Allen wrench is required for that set screw shown above?

[theropod]

Still haven’t figured out what size Allen wrench is needed to manipulate these tiny grub screws, but I have found out that these are M3 X .5mm thread type. None of my many Allen wrenches, and miniature tips used for laptop repair, fit. I’ve seen where someone out the in the cyber world replaced these hex socket grub screws with 10mm long knurled head screws to be able to calibrate the polar scope by hand. I may go that route myself. A rather large fastener company exists close by, and I will visit them within a few days. That won’t do me any good unless I can get these grub screws out! I could modify one of my oversized wrenches with a whet stone, but I would then have a one-trick tool.

I simply cannot believe the polar scope comes from the factory this far from right, and seems to be a common issue with this mount. If one tried to use the polar scope as-is it would be super frustrating. Those in the Southern Hemisphere would be seriously screwed as the etched star pattern would put the scope at least 20° off, and subsequent stellar alignment would be a nightmare. Even modest magnification would put target stars miles from the FOV.

I know how to drift align. My permanently set barn door tracker employs this method. It doesn’t even have a polar scope. I’m NOT going to go through that process every time I set up the mount.

It’s been cloudy, foggy and serious rain is about to set in which is forecast to last for a week, so I’ve only been able to look at my mount, and worry about grub screws. Oh, the third hurricane for the year is about to come ashore south of us. It may be weeks before the mount sees its first use. Sigh...

[Seelive]

A M3 grub screw should have a 1.5mm hex socket. Unfortunately the quality of the screws do not seem to be that good and the size of the socket seems to vary. Two of mine were OK with a 1.5mm hex key but the other one needed a 1/16" imperial hex key (1.59mm) - but it also depends upon the quality of the hex keys used, they also are not always that accurate in the smaller sizes. The grub screws that were fitted were cone pointed so they 'dig' into the graticule holder. I replaced them with decent quality M3 x 3 cup point grub screws.

When I mentioned about the graticule alignment I wasn't refering to the orientation of the graticule, that can simply be corrected so that 12 o'clock and 6 o'clock are vertical by rotating the RA axis before polar aligning. I was referring to the fact that the graticule was not correctly centred. Their are plenty of videos on the net on how to do it. Fortunately it can be done in daylight - I used the tip of a distant pylon so that it remained perfectly on the clock circle as the RA axis was rotated through 360 deg.

[theropod]

Thanks, Seelive. For some reason the board software didn’t notify me of your post. Odd!

I am concerned with both aspects of the reticle. I want the 12 o’clock to actually point straight up. I’ve been using that arrangement for years with my iOptron SkyTracker, and the way the reticle looks now just bothers me. Sure, I could use an imaginary 12 o’clock point, and cipher out where Polaris should line up, but that seems like an invitation for error to me. Yes, I know I could rotate the RA axis to get things straightened up, but I just don’t like that idea. I want the scope as close to plumb as possible when aligned, and set that as the home position. In the end it should make my setup much quicker, and familiar, to get it the way I want. OCD taking hold.

As for centering the reticle crosshairs on a fix point as the mount pivots I am sure that’s no big deal. I tried mounting a low power rifle scope on my barn door tracker, and quickly  discovered how hard it is to use the windage and elevation knobs to achieve this goal. That’s why it has no scope at all now. It should be a simple matter to use those 3 grub screws to get the crosshairs to stay put while rotating. Very similar to adjusting out the finder/spotting scope for the main OTA.

I am going to the hardware store tomorrow and will pick up a small set of both metric and imperial allen keys. Surely between the two I can find something that fits. I have a very nice whet stone, and I’ve made Allen keys fit odd sizes in the past by slowly grinding on the flats. It just takes forever to do this, and I’d rather not. I’ve also read elsewhere about the pointy ended screws used in the mount being problematic, and will see if said store might have cup ended screws while I’m there. If not there are a million options on fleaBay. I just have to buy a handful. I saw where one guy used knurl ended screws to eliminate the tooling altogether.

Again, thanks!

Edited October 31, 2020 by theropod
Clarity

[theropod]

I bought a set of small metric Allen wrenches, and the 1.5 didn’t fit, and was slightly too big. The store didn’t have screws in metric that small, sigh. I took one of my old wrenches and did my whet stone thing. If one ever has to do this take your time and work LIGHTLY side to side along the flats. Stop grinding and check often! That reticle now matches what I’m used to looking at, and more importantly matches the app PS Align. The 0 (zero) etched marking is straight up and the view through the eyepiece matches the app exactly with my OTA pointing at about where Polaris should be.

I’ve also calibrated the polar scope. I used a solitary pine tree lives across the valley from us, about 3 miles away, and served as my target for this chore. It’s what I have used to align my finder with the OTA. I’m happy with the 180° centering. This only took 10 minutes or so. Now I need to check for cone error still, but this old man just ran out of steam today (see below). Besides, high thin clouds (not forecast!) rolled in just as the sun was setting. Sigh.

I screwed up and mowed my lawn (for the last time this year I hope) in anticipation of setting up the mount tonight. I should have waxed my wife’s vehicle just to ensure a trifecta of rain storm inducing acts! It was tiring, but needed done.

I think I have the SynScan somewhat figured out, and can’t wait to get going now that I have things set the way my OCD demands. Sorry to ramble.

 

[theropod]

Tonight! The maiden voyage of the little Skywatcher will be tonight. The sky is cold blue, the air is dry, and hardly any breeze. If I can’t have a little fun on the EP tonight something is seriously wrong, and I’m getting a nap in to make sure I don’t get drowsy before the good stuff happens. Moon or no moon.

I’ve been giving serious thought to why the idea of leveling an equatorial mount came to be. Could it be, that like me, some early astronomers used the OTA for rough polar alignment, and having the reticle crosshairs level and plumb more closely matched charted Polaris placement? If that erect reticle doesn’t look right one could tell the mount wasn’t level.

Additionally, if the tripod is set to level/plumb isn’t the mount more gravitationally centered, and stable by nature? If the mount is level adding a weight to the center would then add to this stability, and I have done this myself to combat wind (futilely at times).

No, tracking and goto are not effected by an out of level mount, but isn’t a more stable mount a good thing? What could it hurt to take the time to get the mount level?

[Seelive]

I don't think that a few degrees out of level would make any significant effect on the mounts stability. Having said that, I always 'level' mine using a spirit level on the eyepiece tray (so it isn't necessarily truely level), hence, along with using permanent marks on the ground for the tripod legs, it means that after the first polar alignment, Polaris is always close to the required position so I don't need to make significant changes to the mount altitude and azimuth adjustment screws in order to polar align.

[theropod]

The mount saw its first use this evening. I didn’t have much issue with either the handset or the polar alignment. Where I ran into problems was with my diy finder scope not being anywhere near right. The finder that comes with the C-90 is a bad bad joke, and my rigged up replacement is off by a mile. It didn’t used to be! Anyway after I finally got Vega centered in the FOV, and accepted into the handset the mount went right to Mars, Saturn, Jupiter and that blazing bright moon. I called it a night early because of that moon washing out the entire sky and a rapidly dropping temperature. We are supposed to have our first frost of the season tonight, and it feels like that is going to happen.

This goto stuff is so seriously cool! The mount is rock steady and tracks like a dream. Jupiter was showing off until it started dipping into more atmosphere. I bumped the mount a couple times and the target was still dead center in the FOV afterwards.

When I ended the session and parked the mount in its home position Polaris was dead center n the FOV of my OTA. I’m gonna love this.

Next time out I’ll have that finder sorted, and do a good 3 star alignment. Then I’ll see if I can  find some faint fuzzies. I still have to learn more about using this handset, and the menu tree therein, but I think I’m off to the races.

[bottletopburly]

Skywatcher do a polar scope illuminate if that helps it should fit https://www.firstlightoptics.com/sky-watcher-mount-accessories/polar-illuminator-for-eq3-2eq5-mounts.html

though it is possible to use Eqmod via suitable cable just unplug handset plug this in and control from your pc a godsend if your starting Astrophotography and once you get the hang of it image from the comfort of the living room , https://www.firstlightoptics.com/sky-watcher-mount-accessories/lynx-astro-ftdi-eqdir-usb-adapter-for-sky-watcher-eq5-pro-heq5-syntrek-pro-az-eq5-gt-az-eq6-gt-and-eq8-mounts.html

if you do go this route and you go the Astrophotography route then you can polar align using sharpcap pro which uses your guidescope to pa then you won’t need a polar scope illuminator .

 

 

 

[theropod]

Down the road all that may happen, bottletopbury.

For now I’m going back to the supplied finder that cam with the C-90. I am, however going to modify/hack it to actually work, and the little O ring inside the rearmost ring is going bye bye. I am going to drill and tap the rearmost scope ring so the finder is supported and adjusted on both front and back rings. That O ring only compresses so much, and changes flexibility with temperature. If needed I will build up/shave down the dovetail in addition to the new screws. The optics, and coarse reticle, of the finder are acceptable, it’s just the mounting system for this little scope is insane. Simply copying the forward screw locations should make the finder actually usable.

Before I try serious picts, guiding and all the other fun stuff I need to get the fundamentals down. I’ve got to use a finder that actually works during 1,2 or 3 star alignment because of the narrow FOV even with my 32mm EP with my little Mak. A nice illuminating reticle EP for said Mak to assist in this procedure is at the top of the list of goodies I need. A fixed income means I have to parcel out my “improvements”.

For some reason it was very satisfying to tap “home” and have the scope park with Polaris dead center of the EP. It was like rolling in a birdie putt to close a round.

[theropod]

I made good on my promise to myself to fix the poor design in the supplied finder scope aiming with the Celestron C-90 Mak. The scope is acceptable for my current needs, but I’m not married to it.

My solution was to carefully copy the location of the existing adjuster holes, use my Exacto to spin a pilot point, drill and tap these fresh holes for the socket head screws seen in the forward ring. No drill press, a small variable speed drill held steady on my lap with the ring/mount in my left hand. The tap was held in place a pair of linesman pliers, carefully. I again held the pliers/tap steady on my lap with the ring/mount assembly in my left, which I turned into the tap by hand. This injection molded part drilled, and took threads, well.

An O ring was supposed to, somehow, do what these new screws are doing. What these new screws are doing should be obvious. Now a double crosshair OTA EP with illuminating reticle will get me those 2-3 star alignments with far less hunting. The brand new tooling, cleaning the chips and working as slowly as possible gave me some clean strong threads. I think one of the factory screw mounts is out of square (one right back as shown).

I readjusted the reticle and it only took a few minutes. I purposely thumped the eyepiece end, and objective end, like flicking a bug away, and the crosshairs stayed dead on that pine tree miles away.

What this has to do with the new mount is my post Polaris stellar alignment, and the 1-2-3 star tuning required o get the mount down to business. If I’m gonna look for the faint fuzzies with a small scope I better be pointing at the right place. Compound a narrow FOV with that, and pointing just a bit off isn’t fun. So, I needed to be able to use a finder scope that actually finds something, consistently.

Total spent to add the new screws? $6.50, tooling and all.

Time spent crafting and realignment with OTA? 20 minutes.

Value added to the process? Priceless!

(Sorry, I already have my hat)...

[theropod]

My 12.5 mm double crosshair illuminating eyepiece arrived today! Cloudy as can be, but it’s supposed to be clear Wednesday (figers crossed), but markedly cooler. I’m so excited. I’m doing a firm 3 star alignment and test the mount and my little scope.

[theropod]

Upstate:Last night was no good at all. That disgusting C-90 Mak finder I worked on let me down, pointing a dozen degrees off, which screwed up stellar alignment big time. By the time I had things half right I was cold and tired. Beginning to think my little narrow FOV Mak might not be the scope for this.

Edited December 7, 2020 by theropod
Typo

[theropod]

Help!

Is there a way to “tune” the synscan on the fly? What mean is when I enter a goto target, the mount slews and is just slightly off, is there a way to “teach” the mount that it was off and the correction then stored in the system?

My DIY 60 mm refractor does very well, but I need a dang finder for it too. Ah, the list just never ends does it?

[Seelive]

5 hours ago, theropod said:

Help!

Is there a way to “tune” the synscan on the fly? What mean is when I enter a goto target, the mount slews and is just slightly off, is there a way to “teach” the mount that it was off and the correction then stored in the system?

My DIY 60 mm refractor does very well, but I need a dang finder for it too. Ah, the list just never ends does it?

Their is the Pointing Accuracy Enhancement feature (see under tne Advanced functions of the instruction manual) but I suspect it might not be quite what you are looking for - the enhanced accuracy is generally only applicable to sky zones where it as been applied (85 zones for the whole sky) and all data is lost upon re-doing star alignment.

[theropod]

I’m beginning to think I will need to install ASCOM/EDMOD on my wife’s laptop and stop fighting the post polar star alignment. I went out last night for the first time since early December, and fought with the damned mount yet again. Even after getting those 3 stars locked down any target I pick is off by several degrees. I’m very frustrated as I bought a new 9X50 RACI finder, which is a dream come true, but the goto function seems screwed up to me. I honestly think that with only a handful of nights spent with the mount to be the real issue, but I thought I was doing everything right. Apparently that thinking is in error. I’ll figure it out, but this is frustrating. I’m convinced there is plenty of room for improvement in the synscan system/menu tree, and a big motivator to figure out a solution. Hopefully the laptop driven mount software will lower the frustration level.

The mount tracks like a dream when I finally get a target in the eyepiece. I watched M42 drift across the sky for a couple hours and the view didn’t change at all over that time. Trying to find M1 via goto was a total waste of time, and I ended up star hopping until I finally put the little smudge in the EP. about that time some very high thin clouds started infiltration and I broke down the entire rig slightly angry. I had high hopes that the Crab would just lock in instead of some empty hunk of sky. Almost beginning to think the whole goto idea is a farce, and some sort of black magic. Maybe I need some goats to sacrifice to the astro gods...

[tonylumley]

but if it was "easy" we would soon get bored!, I always get a "satisfied" smirk when the weather gods and the star gods deem to come together and let me see properly but then I might just have a masochistic streak! 

[theropod]

I’ve got the green light from the wife to use her laptop to download the mount software, drive the mount and run Sharp Cap with my little SV105. I’ll get this figured out. I just need more nights not smooth cloudy and or raining. I already found that Sharp Cap can synthesize a dual crosshair for those 1,2-3 star alignments, which will help. Yep, if it was easy it really wouldn’t be any fun. Besides, this scope centric stuff is secondary to my main love of night skies, with my primary drive to capture meteor falls with a camera. I can have my meteor hunting rig running while I gander at the faint fuzzies, if I can figure out my mounts quarks.

[smashing]

4 hours ago, theropod said:

I’ve got the green light from the wife to use her laptop to download the mount software, drive the mount and run Sharp Cap with my little SV105. I’ll get this figured out. I just need more nights not smooth cloudy and or raining. I already found that Sharp Cap can synthesize a dual crosshair for those 1,2-3 star alignments, which will help. Yep, if it was easy it really wouldn’t be any fun. Besides, this scope centric stuff is secondary to my main love of night skies, with my primary drive to capture meteor falls with a camera. I can have my meteor hunting rig running while I gander at the faint fuzzies, if I can figure out my mounts quarks.

I guess the nuclear option if you have a camera on it is to plate solve and never worry about 3 star alignment or finding targets ever again.

Edited March 8, 2021 by smashing
Missed a bit

[theropod]

Yes! I’ll show my wife this post. I agree entirely. Celestron Star Sense springs to mind. A good choice or is a better solution out there?

[koningmokum60]

A tip for aligning the reticle in your polarscope.  Replace the fiddly M3 x 0.5mm grub screws with M3 x 10mm thumb screws.  Even plastic ones will do the trick.  Replace them one at a time, so the reticle doesn't fall off the other two grub screws.  You'll now have far better control aligning the reticle.  You'll be able to loosen one screw and twiddle the other two with your fingers.  You can pick them up for cents on ebay.  No more messing with tiny Allen keys.  Clear skies 🌌🔭.