Jump to content


Sumerian Alkaid 12" Review and Mods

Recommended Posts

Well hello again!  It's only been almost a year since I last posted about my acquisition of a Sumerian Optics scope (https://stargazerslounge.com/topic/325179-binos-on-a-sumerian-alkaid-12/), and all my queries about how well binos worked with them.  Please pardon the delay... life got in the way to the extreme.  Thank you BGazing for the nudge to get back to it.

In that thread, the topic was mainly about asking around about anyone’s experience with binoviewers on a Sumerian Alkaid 12", but my posting here ends up being a little more of a review, so I thought a new thread with an appropriate title would be the proper thing to do.

I'm gonna nerd out here pretty hard, but it's the sort of stuff that I look for when I'm doing all that research on what to get in the frst place.  I wanted to share, because the things I've done to the scope has made the experience even better than it already was, and if it's inspiration to anyone on their own ideas on making the thing their own, well that's awesome.

So I ordered the Sumerian Alkaid 12" f/5 in December of 2018.  The intent to get a travel was prompted by my plans to go to Chile for the July 2, 2019 total solar eclipse.  I figured ordering as early as I did would allow Sumerian Optics to build and ship the scope in time.  It got hung up in US Customs in Nashville, Tennessee and showed up at my door the day before I got back from Chile!  😖  Oy!

Anyhow, the scope is here and I unpacked it with great enthusiasm.  It was well packed (spooley storm), and the box (as shipped from Teleskop Express) contained the manufacturer's box (the one Sumerian shipped to Teleskop Express).  It was to my relief that the manufacturer's box had my name in big letters on the box.  It was a relief because my scope was to come with a specially-ordered Moonlite focuser (their choice of focuser, but my choice of model) with a 2.7" focus travel to accommodate all three magnification settings on my Denkmeier Binotron 27 binoviewer.  In purple.

One helpful note:  As I’m in the United States, I could only order a Sumerian scope through Teleskop Express.  They were not very good at communication, and though I can’t say whether or not the language barrier was a factor, they just didn’t seem to want to answer questions.  That’s the impression I got, anyway.  However, I did contact Michael, the owner of Sumerian Optics and the builder of the scopes, and that made all the difference.  I was able to ask my questions about considerations with binoviewer usage and I was able to choose the focuser to best suit my needs.  In my case, that 2.7” of focus travel.  In purple.

As stated before in other reviews, the instructions were good enough to figure out and I easily had the scope built.

Given that the purchase of a new telescope causes cloudy weather, I took it out for first light a few nights later when the sky decided to stop taunting me.

The mirror is the standard GSO mirror... I did not opt for the fused quartz mirror.  I understand the quartz is superior in terms of lower thermal expansion and lighter weight for the application, but I didn't find the benefits valuable enough to me to pay the extra coin.  The mirror I got is a fine mirror.  It’s a bit heavy, but it's consistent and clean.  It’s as bright as I hoped it would be and have read in other reviews.  I do not perceive any coma around the edges of the field, so there's no need for corrective lensing like the Paracorr.  Perhaps a greater chance for coma on the faster f/4.5 version, but not the f/5.

By the way, my Denks have the OCR-45, which is their big aperture one.  I use the binos with both of my dobs and it comes to focus in them, no problem.

I also got the encoder set, which is an option at Teleskop Express when ordering.  I bought an Argo Navis to read the encoders and I added a SkyBT to enable it to talk with my Android mobile's SkySafari app.  This makes the scope a "push-to", which is my first experience with that.  I have a dob with go-to, and I love it.  The push-to is fantastic.  What a clever alternative to go-to/motors!  For those that don't know, that means I can select an object in SkySafari and press the go-to command (or on the Argo Navis itself) and the Argo Navis tells me to move each axis in a certain direction and it tells me in arcminutes how far I have to push or how far past I've gone to get to the object.  Well, I just think that's cool.  LOL

The bonus to the Alkaid as a push-to with the Argo Navis and the SkyBT is that the Argo Navis and SkyBT are battery operated.  That means I can use the system stand-alone without having to plug anything in and still have totally assisted navigaton.

The push-to also renders the red dot finder used only for initial alignment, and then you can shut it off and forget about it.

Also, the scope settles down quickly after moving the alt and az.  The scope is stable when viewing.

The encoder set comes with cabling, which I modified.  More on that later.

The fantastic and inspiring review by GuLinux (below) covers most of what I'd say about the scope, but I will speak to a few new things here.  By the way GuLinux, your review was a key to my decision to go with this scope, so thank you!  Yup, I watched the video of you guys building it, and everything else you put up about it.  So I'm hopefully passing it forward.

I tend to "pimp things out".  I would suppose back at or before Thomas Edison's time, I would have done quite well, and all the while not being a total jerk to Nikola Tesla.  What I mean is that I seem to know how to take some simple aspect of something and engineer a way to vastly improve upon it, even if it was pretty good to begin with.  For me, geeking out on the mods are half the fun of getting a system together.  And after my customizations, I literally have the system perfect so when I use the scope, it's exactly the way I want it so I can focus on the use of it and not be fooling with even the slightest shortcoming or inconvenience that I might have experienced with any of the original system.

1)  Balancing the Scope

The scope comes with two pretty stout bungee cords (aka “shock cords”) to create balance using tension rather than counterweights.  I had originally anticipated that I would need some sort of counterweight to accommodate the added weight of my binos.  It was even something that the owner of Sumerian Optics had suggested I consider and/or additional bungees.  The bungees fasten to the scope base on and around these pins that screw in that stick out of the side of the base and the side of the mirror box.  Each bungee has a loop on each end to go on a pin and the middle of the bungees do a turn around other pins.  This creates tension as, when the scope is tilted, the pins spread apart from each other and stretch the bungee.  The suggested configuration of putting the bungees on was fine as my starting point, but when I put on the binos, it wasn't enough.  So I ran the bungees in other configurations around the pins and even used a couple of the knobs there around where the pins are... et voila!

Therefore, I am happy to report that with a 4.5 lb set of binos, the Denk's "filter switch" and "power switch", and two little glass-packed footballs for eyepieces, I do not need counterweights.  I simply needed to play with the bungee configuration until I got it right.

Eyepiece side - Manufacturer’s bungee configuration suggestion: (left) vs my solution (right): 


Far side - Manufacturer’s bungee configuration suggestion: (left) vs my solution (right): 


PS... my way of doing it (the ones to the right) supports the weight of my 4.5 lb Denkmeier Binotrons at ANY angle the scope is at.  This is a bona fide solution for the bino, folks.


2)  Getting a Full Shroud

The "shroud" that the scope comes with is a round piece of thick vinyl-like fabric that fastens to the top of the scope.  It's just a light shield at the eyepiece.  You really need a full shroud to protect the primary from dust and dew, plus a full-length shroud is critical when using the scope for solar viewing with a white light filter.  Like GuLinux, I used the knobs that go to that shield elsewhere for one of my modifications.

I ordered a shroud from "Shrouds by Heather" (https://www.scopeshrouds.com/), which is a US company that also makes the Teeter's Telescopes.  Husband and wife thing... great folks.  I made the measurements and ordered a full-length shroud.  When I got it, I found it to be a bit long, which was my fault, so I took it to a tailor to have it shortened a bit.

Note:  If you order a shroud, make sure to ask for rounded elastic cord to be used instead of flat, ribbon-like elastic.  The elastic has to fit over knobs on the scope and the flat ribbon elastic doesn’t sit as well.  Also don’t forget about having a focuser cut-out done.

I got the shroud back from the tailor, and it fits the scope perfectly.  The proper length to indicate should be 46.5 inches.  Of course, it's pouring rain outside, so when I see the sun out again, I will get the scope out with the shroud on and put on the white light filter to check out the sun.


3)  My White Light Solar Filter Attachment

I bought some corrugated polypropylene board.  It's like corrugated cardboard, but made out of white plastic, and it is acceptably stiff for the application here.  I essentially made a big dial that allows me to select one of three different size aperture masks according to the seeing/magnification.  I've read that it does make a difference and I've read elsewhere that it might not, but I made it anyway.  The apertures are of course in between the spider vanes, and the fourth space is the blank selection where there is no hole in the mask.  That setting is what I'd use for transporting the mask.

I also have an IR/UV cut filter at the end of the binoviewers to further reduce any UV radiation that the white light filter transmits through.

687531314_FilterTransportBottom.thumb.jpg.a734802d9627b34cdee9043b9b72efa4.jpg597491747_FilterLidOff.thumb.jpg.670dbf1de17f55024a3b9463a5e6e923.jpgFilter Affixed.jpg1497114247_Filterat90mm.thumb.jpg.cd51b42f70026785755df0c63e2ebc0d.jpg1977913311_Filterat70mm.thumb.jpg.beefd65c9044da61f4df41cb1224c312.jpg48371612_Filterat50mm.thumb.jpg.ed11742b285c1e0fad1c75a828394a90.jpg1528996117_FilteratClosed.thumb.jpg.5e0538c0225541688ae701af9b3c3b12.jpg

Now where the hell is the sun????

4)  My Customizations

Low Altitude Stop:  I found that if you try and go too low in altitude with the scope, the scope will literally "fall off its rocker" and with bungees in tension, it is not only a very startling jolt when it happens, but you then have to undo all the bungees to get the scope back on its track.  It needed a limiting plate, so I fashioned one out of aluminum plate.  Problem solved.  And it's attractive.


Argo Navis Mount:  Instead of having some stalk to hold the Argo Navis like you see on some rigs, I wondered how I could mount it on some existing part where the display would be visible when doing the push-to thing, in a good place for the cables, and to be out of the way and clean from a cabling standpoint.  The suitcase handle is on the back side of the primary mirror box, and what I found as the perfect place to affix the Argo Navis.  I riveted some velcro to the plastic holder that came with the Argo Navis and put velcro on the bottom of the handle for a secure attachment.  God I love Velcro.  I have a spool of the stuff that has an adhesive backing so strong that I literally need pliers to pull off the stuff if I don't get it on there right.  Given that, I use tweezers for careful placement.


Cabling:  The cables that come with the encoder kit are LONG, and it may be because some folks like their Argo Navis on a stalk.  Per the above solution, I shortened the cables (need crimpable connectors and a crimp tool of course).  That eliminated the coils of excess cabling, but I had the issue of the cable that bunches up at the back when you take the altitude of the scope to straight up.  At that point, or anywhere near it, you now have a potential for the cable to snag on the base or something on the ground.  As I'm sure I have made you realize by now, that just wouldn't do, so I bought some 8-conductor curly ethernet cord (like an old landline phone cord... remember?).  This would keep the cable off the ground and out of the way, and would stretch when the scope's altitude was taken closer to the horizon.  Gosh, that's really fussy, but it's a good mod and I am certainly unconcerned about snags now.  Sorry, I'm a bit of a freak show about tidy cables.

The leftmost is the shortened cabling, eliminating all that excess cable.  The next pic shows how I color code the connectors where they mate with a spot of nail polish.  The third pic shows one of the two bungee-string strain reliefs on the curly cord.  This takes the stress off the connectors entirely.  The rightmost two pictures shows the curly cord in action with telescope at vertical, and then at horizontal.  Sexy!


Secondary Knobs:  The secondary mirror comes off, which is part of the scope's ability to break down into a suitcase, but doing collimation becomes a pain when you only have knobs on two of the three pressure points.  I think I took a knob from the unused shield and used that, or I bought one, and now collimation is as easy as it should be.  I'm not sure why Sumerian does that two-knob thing.  I consider it the only real design consideration shortcoming of the entire system.  Well, maybe that and the low altitude stop.  GuLinux suggested this, as have a few others, and it is the way to go.

One thing of note:  As the secondary is detachable, that means the secondary is only held in place in use on the telescope with nothing more than the pressure these three knobs put on the mount plate on the back of the secondary.  There is a dew heater, and a cable off a spider vane plugs in to a port on the secondary assembly.  This does double as a bit of a fall safety connection, as in the case you lose grip of the secondary with the knobs and the secondary assembly falls, the cable will keep it from crashing down into your primary or onto the floor/ground.  BUT… you’ve got those knobs too.  One just has to be careful with getting the secondary mounting done slowly and carefully.

Secondary in Transport.jpg924262660_SecondaryBracket.thumb.jpg.fd8d51518c7e7fbe5713d3e499012c86.jpg434975018_ThreeKnobsonSecondary.thumb.jpg.8a06cc841052de24e1b829d888c0af16.jpg733319511_SecondaryAffixed.thumb.jpg.57d43ba128b496caafb2fa28cf346008.jpg

Added Storage:  There are a couple of bits that don't seem to have a place in the "suitcase" - but should, such as the altitude encoder arm - so I simply put in Velcro on the bits and the inside of the base to get it all in there.  I also have a little bag with a soft interior that I put over the secondary mirror after I mount it to the inside of the base... just to protect it a little more.  Once you have the "suitcase" complete, you have all the pins, the knobs, the bungees, the encoder cabling, the Argo Navis, the SkyBT, the truss poles, and the shroud left to store separately.  In addition to the white light attachment, it all goes in a backpack, with all the little parts stored in Crown Royal bags I’ve accumulated through the years.  I honestly don't know why I have so many Crown Royal bags.  I don't remember drinking that much Crown.  😜 Ah, youth.

1012301552_Layer4-BottomLayerofBaseinTransport.thumb.jpg.eaf43a75cd7f129d127ddd6cc75d8b71.jpgThe Parts Kit.jpg

Altitude Encoder Arm:  If you need to move the scope, you can pick up the scope "tube" off its base with relative ease... it's very lightweight.  You just have to hold it on both its mirror box's handle and the top aperture ring so as not to stress the truss poles.  You run too much risk of having a tragic accident if you try and pick up the whole thing together, scope and base, because that has you holding the base and you've run out of hands to keep one hand on the scope.  So you get the scope part off the base and set it aside so you can move the base to where you want it, then pick up the scope and place it on the base again.  Now if you have the encoders, the altitude encoder is affixed to an aluminum swing arm that attaches to both the mirror box and the base to allow measurement of the altitude.  Problem is, when you lift the scope off its base and then go to set it down, you get that swing arm in the way and you risk bending it.  Yes, you can remove the swing arm for short distance transport, always super fun to fiddle with little knobs, but when tired of that I've found that if you put a little piece of loop Velcro on the inside of the arm and a little piece of hook Velcro on the knob conveniently placed near the arm, you can do a little move and get the swing arm to come up and stick and stay so you can set the scope tube down without the arm getting in the way.  It seems like a little thing until you need to move the scope and you don't remove the swing arm.  Once you restore the scope to its base, you can carefully tilt the scope off its track on the altitude sensor/swing arm side and get the end of the swing arm on its pin where it normally resides in operation.


A Little Idiot-Proofing:  The more I can do to remove the "now, which way does this thing go together?" moment, the better.  Especially with a kit like this that breaks down into a lot of parts.  Maybe I just like playing with my label maker.


5)  My Kit


Aside from the binos and the EPs, the pic to the left is the whole thing, with all the parts and my mods in the backpack.

In my modification efforts, I go all the way with it.  I consider storage and safe keeping of the accessories, and I consider the means by which the entire kit is transported.  Here's a picture of that kit, which can go on my back while I carry the "suitcase", or put the backpack in a regular luggage suitcase.  On a plane, I would have my lovely assistant have the binos/EPs case as her carry on, and all delicate optics are safe from getting tossed about by the baggage handlers.

In taking the pic of the whole kit, I couldn't help but give a nod to GuLinux's girlfriend's toes...

I love this telescope, and now I have not only a scope fit to transport on an airplane, and a scope with big aperture potential for white light solar, but also a quick “get-and-go” scope for impromptu viewing wherever I go or at home.  It is such a good scope.








The Parts Kit.jpg

Edited by BillyBoyBoy
Had to fix some rogue pictures
  • Like 6
  • Thanks 1
Link to post
Share on other sites

Great stuff Billy! I have the 14" version and love it. I don't use binos with mine but found a similar solution using bungee cords was necessary when using heavy 2" eyepieces such as a 30mm 82 degree ES.

My scope came with a piece of PTFE fixed to the end of one alt bearing which acts as an end stop at low altitudes. Not particularly pretty but does the job!

I have left the bolt in as the third collimation point on the secondary as I actually find it quicker to set up that way. The bolt acts as a fixed reference point for position of the secondary so you have less to adjust each time. I think that's why Michael fitted it like this.

I must get round to ordering a shroud, I've done without so far but it really would be useful to have one. I've not suffered from dew so far but it would help reduce glare when observing in less that ideal places. Yours looks great!

Finally.... I love the encoders and would really like to fit these to mine. I think I enquired before with TS and was told they couldn't be retro fitted to mine as it wasn't built to take them. I'm sure it must be possible and it is such a great system. The RDF on the Alkaid is pretty awkward to use, so push-to would make life much easier.

Thanks for taking the time to write up your thoughts 👍👍

Link to post
Share on other sites

Thank you, Bill, for this extensive review. Excellent read. Very encouraging to hear that it is handling 2kg of binoviewers with EPs without seeming to lose colimation.

Don't know how heavy is that Argo Navis but I guess when velcroed to the carrying handle it acts as a sort of counterweight, too. 

Can't wait to receive mine, hopefully the galaxy season won't be a complete washout. :)

Link to post
Share on other sites

Thank you!  Hey, it seemed a good thing to put together with the rain and clouds.  Yes, this scope keeps its collimation very well in use, and even in moving the scope short distance in the process as I described above.

The Argo Navis doesn't weigh enough to have any practical effect, but the handle was where I was going to put a counterweight had I ended up needing one. 

An update to my report...

Use of the Solar Aperture Mask:

I had a sunny day today and with the appearance of the mighty 2750 region (not), I pulled the scope out with my white light filter. The scope did great with the filter on, and the variety of apertures in the mask did make a detectable difference, especially at higher magnifications.


As with any dob, it's good practice to collimate every time you use the thing, and of course the Sumarians must be collimated when they're built.

The tough thing about collimating these scopes vs a regular dob is the fact that when building it, the secondary has to be put on the spider, vs it just staying on from use to use. 

Having to reaffix the secondary when you build the scope means some extra attention you have to give to the squareness to the focuser. 

I had enough of that challenge today and came up with this:


It's just a piece of cardstock that has a hole for the beam from my laser collimator to go through. Being able to see where the laser beam is on its return trip from the primary mirror enabled me to get the secondary affixed quickly and squarely with the focuser to have little to dial in on the primary.  As you can see in the pic, I even was able to see the dot on the paper in the secondary's reflection in the primary. Woot!

The top of the paper had a bit of Velcro on it to set it in place with the hole centered on the back of the focus tube. Good times!


  • Like 1
Link to post
Share on other sites
  • 2 weeks later...

Thanks Marco!  Your reviews were key to my decision.

Texas has been subject to a change in the jetstream over the last year or so, resulting in lots of blog reading at night... cloudy days and nights seemingly for a whole year, but we're finally starting to see some clear skies on a regular basis again.

Link to post
Share on other sites
  • 3 months later...


I got this yesterday, and noticed also the low altitude stop missing. (The handle acts nicely as high altitude stop)

This is my prototype for low altitude stop. It is too short now, but it seems to work. Now I need to start hunting for a longer one...




  • Like 1
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    No registered users viewing this page.

  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.