Astronomy Shed Build

This past winter, we had planned on staying a month at Rusty’s RV Ranch in Rodeo, NM, then head back into Arizona for a few months. After three days in Rodeo, we canceled our Arizona plans and extended to 3 months, but that too would prove not to be enough.

Rodeo, NM is not a highly populated area nor a resort destination for most. However, because of this, it is a VERY dark sky site. Some of the darkest skies in the US. It was so dark that during the night on a new moon, I could walk around and not trip over anything with nothing but the light cast off of the Milky Way and other star’s light. We were… in awe.

One of our reasons for visiting Rodeo was to scout the area and consider building a remotely operable observatory. I’m a bit of an amateur astronomer, but because we’re generally in cities and have to concern ourselves with light pollution and personal property security that tends to outweigh the desire to break out all my gear (only to tear it back down a few hours later).

The TurtleHerding AstroShed

Rusty’s RV Ranch is a prize find for astronomy and birding buffs alike. Rusty, the owner, is very serious about preserving the night sky. Exterior RV lighting is prohibited, and you must use red lights when walking around after dark. For vehicles, parking lights only should be used after dark when driving through the ranch.

Early in our stay, I mentioned the scouting efforts to Rusty, that we were looking for a suitable location for a remote observatory. Rusty let me know that she and Tim have plots of land which are available to lease for just this purpose! Further, I was introduced to someone with an observatory just down the road from Rusty’s and got to see a lot of his great solutions to issues which I’d been struggling to work through thus far ( like, how to secure the rolling roof once closed so that high winds would not blow the roof off ). Within a week or two, I had signed a lease and ordered the building which would become my remote observatory!

Special Thanks:

Before continuing, I’d like to extend a massive ‘THANK YOU’ to a fellow astronomer that I met at Rusty’s. Mark, whom you’ll see in just a few photos, was a huge help. He introduced me to Don, who’s own astronomy shed was the inspiration for mine. He provided loads of hands-on assistance, including digging holes, swingin’ hammers, holding things while I was sawing, hammering, drilling. Mark put in countless hours and is the reason my first astronomy shed turned out so well.

There were also many others who extended a helping hand or tool along the way. Dennis, Jason, Eric, Chris, Tim, Bob, Rusty, among others. Thank you all for your part in making this dream a reality.

And, of course, to my darling wife. She gave me the OK for this endeavor and tolerated my obsessive toiling, planning, talking about this project as well as me being out of the RV working on it for weeks on end. Thank you, my sweet. I love you.

Work began immediately.
(NOTE: This post is very long, relatively detailed and full of pictures.)

Here’s a quick breakdown of the items tackled:

Clearing the land and a driveway back to the corner lot that I’d picked ( northwest corner ).
Cleared Astronomy plot
Planning for all the materials required for the build and getting them delivered.
- I mentioned that Rusty’s RV Ranch is remote, right?
- Luckily, Valley Mercantile is about 20 minutes drive away in Animas, NM.
- The Mercantile had a surprisingly good selection of materials and even coordinated ordering in some of the less common items ( 20′ long 1/4″ x 4″ plate steel for example ).
- They were able to deliver practically all of the major building supplies right to my build site!
Measuring and setting up a foundation for the shed.
- I decided to dig holes and bury concrete blocks. I wanted the foundation to be deep enough not to wash away or settle in the monsoon season of the desert southwest, but high enough to keep the building above the ground to prevent water washing up onto/into the shed.
- Were I to do this again, I’d pour concrete footers instead. Getting the blocks even remotely level and at the same height as each other proved nearly impossible. I ended up shimming quite a bit to ensure the building was itself level and evenly supported.
not a pet cemetery…
Carefully measure and pour the concrete footer for the telescope pier.
- I wanted the concrete to stop just below the subfloor of the Astro-shed. This configuration would permit me to cut only small holes for 1/2″ all-thread to stick up into the shed and mount the telescope pier onto those all-thread rods.
- Thus, meticulous measuring was required since the square shape of the footer would need to fit between two-floor joists of the shed. This ultimately worked out very well, much to the surprise of the shed delivery team.
Getting the building delivered and set over the concrete footer for the pier.
- It was dark by the time the building arrived, which made things a bit more tense getting it set into the proper position.
- Further, I had to drill four holes through the floor for my all-thread rods to poke through.
- The delivery team did not think this would work. I re-measured everything one last time and confirmed that the concrete would be just 2″ below the floor, nestled right between the floor joists with only 3/4″ clearance to the joists themselves.
Shim the runners under the building to ensure it was level and evenly supported, as well as positioned so that the all-thread was centered in the four holes I’d drilled.
Get initial power setup at the shed.
- I started with 2 x 300-watt solar panels and a ~100Ah deep cycle battery. This setup was temporary, just waiting for other power items to arrive and allowed me to run some network gear.
- Once my primary power storage arrived ( a 5.2kWh Tesla battery module ), I converted over to it and added a 1000 watt inverter. This power system permitted me to run any AC load I needed, which mostly consisted of recharging the batteries for my various tools.
Splitting the roof!
- One key aspect leading to the choice of the Graceland Portable Building’s Side Lofted Barn was that its roof to wall interface was the same height around the building ( no staggered height between end and side walls ) and had two 2×4’s at the top as the wall plate.
- This meant I could separate the two 2×4’s, leaving one attached to the roof segment, and one attached to the top of the wall, then reinforce where necessary.
- I could also lift the roof and install my track, plate steel and rollers with relative ease (although this was tougher to execute than I’d expected initially).
Build the roll-off support system.
- With the building situated and the roof split, I now knew precisely where my support tube steel needed to be to support the roof in its rolled-off position.
- This support structure took the form of two 4×4 square tube steel horizontal beams, each held up by three 4×4 lumber posts that were themselves concreted into the desert ground.
- These horizontal beams would then have 4×4 lumber connecting between them in the air.
- And finally, a 2×2 square tube steel beam would ride on top of these cross-connect timbers for the drive chain mechanism. This 2×2 square tube is centered between the two main beams and thus, is the centerline of the building.
- Note that the roll-off moves to the north so that the southern sky remains open for imaging.
Roll the roof and secure the wall toppers.
- Once the concrete had set, and all the tube steel and timbers were in place, I rolled the roof onto that support structure for the first time.
- To my amazement, it rolled with VERY little force. So little, in fact.. that when pausing to admire the work, a 3 mph breeze blew by and the roof started to roll without my input! That was a high pucker moment as I grabbed the roof and promptly secured it with some clamps.
- On the East wall, I secured a 1/8″ x 4″ piece of plate steel. This steel plate provides some weight carrying support, but mostly restored a great deal of stiffness to keep the wall from bowing out.
- On the West wall, I added not only the same 1/8″ x 4″ plate steel, but also V track designed for rolling gates to move on.
- I did not apply the V track to both walls to prevent any risk of binding. With the East rollers allowed to float on the plate steel, any twist or shift in the roof would easily work itself out on the East wall side.
Cut out the South wall of the gabled roof and mount it to the South wall of the building.
- I decided the South wall of the gabled roof would be affixed via hinges to the South wall of the building.
- This opening would allow the roof to be opened, or more importantly, closed, no matter the position of the telescope.
- The South “flap” would be connected to a linear actuator so that it too could be lowered for imaging in the southern skies.
Fashion my “anchor” system for holding the roof down when closed.
- Huge thanks to Don who’s shed inspired mine for having figured this part out (along with many other aspects of this conversion). His insights saved me loads of failures and re-work.
- The solution is straightforward — 1/4″ plate steel and 1/2″ bolts.
- The plate steel is affixed to the roof on the South end, and the building wall on the North end.
- Then the 1/2″ bolts are affixed through the South wall flap at the top, and through the North wall of the rolling roof.
- The plate steel is drilled to allow the 1/2″ bolts to slide into them and thus, interlock.
- This system allows the roof to roll open/closed with ease.
- However, once closed, the bolts are interlocked with the plate steel, and the roof cannot lift away from the building.
- Genius! Thanks again, Don.
  The nut and washer on the bolt were temporary until I completed the roof drive mechanism.
Make the shed weather tight again!
- I’d make a lot of gaps!
- The tops of the walls to the bottom of the roof was now about 3″ separated.
  - For the side walls, the solution was to affix a new rough outboard under the soffit.
  - Staple a long strip of EPDM rubber to the outside under the soffit to the new rough outboard.
  - Then, roll it under and staple it on the inside edge of the same rough outboard.
  - This configuration produced a simple D-shaped bulb seal with the rounded portion of the EPDM rubbing against the plate steel.
  - To finish things off, I covered the whole thing with a finished board on the outside and painted it to match the building. This finish board runs alongside the outer wall as the roof rolls.
- The South wall flap had a similar gap with a need for a different solution compared to the side walls.
  - More EPDM rubber and finish boards, but this time, the EPDM was left to flap down over the wall at the hinge point.
- The North wall was similar…
  - Another EPDM rubber flap stapled to the rolling roof’s north wall with a finished board over top.
  - The EPDM rests against the outside of the north wall of the building when the rolling roof is closed.
  - Care had to be taken to ensure the finished board would pass over the cross supports between the 4×4 tube steel and leave enough room for the EPDM flap and not bind.
Insulate the roof and walls.
- I insulated the roof with a product commonly referred to as Reflectix.
- Basically, it’s bubble wrap with an aluminized plastic backer. It staples in place and provided both insulation and dust mitigation since the roof is ventilated at the top and bottom for better heat management.
- I insulated the walls with R-11 batt insulation.
Install the wall boards.
- I opted for 7/16″ OSB for the interior walls, then painted them for better water resistance ( incidental dew / sprinkling of rain — nothing heavy )
Re-work / finalize the electrical system
- Ultimately, I found that once the heating / cooling loop was installed for the Tesla battery module ( LiPo batteries cannot charge when below freezing without severe damage ), the power drawn by the heating element on cold nights was not generally recovered from the 600 watts of solar panels on cloudy days.
- I added two more 300-watt panels along with a second 5.2 kWh Tesla battery module.
- Was this overkill? Oh ya! But, I didn’t want to risk having a great night clear up after a week of clouds, but not have enough power to safely roll the roof and use the gear.
- With 10.4 kWh of storage and 1200 watts of solar panels… The batteries always make it back to full charge, even on cloudy days!
Design and install the rolling roof drive mechanism
- For this, I went with a 1 Horsepower DC motor and a 60:1 reduction gearbox.
- This gearbox drives a #40 chain which goes over the 2×2 square tube steel, then around a sprocket at the far end, and returns inside the 2×2 square tube steel.
- This design prevents sag in the chain and keeps it a bit cleaner than it would be otherwise if the entire length were always exposed.
- This design was also something I borrowed from Don’s build. It turns out, he’s done this a few times now, and I have definitely gained so much from his experience.
Design the drive electronics for the rolling roof / South flap
- I ended up building the same setup for each end ( rolling roof on the North end, a linear actuator on the South end )
  - A reversible, variable speed DC motor controller
  - A dual relay board
  - An Arduino Nano
  - A CAN-bus interface board
  - Limit switches for the rolling roof
- The Nano’s control the relay board which handles enabling of the DC motor controller as well as dictating which direction to operate.
- The two Nano’s communicate with each other and a Raspberry Pi 3B+ over the CAN-bus.
- The Raspberry Pi 3B+ provides a web interface as well as an ASCOM Alpaca interface to the roof controls and ensures the roof and flap operate in the proper sequence.
- The Raspberry Pi 3B+ also interfaces with my two weather stations and provide both an ASCOM Alpaca interface for the environment, but also the ‘safety’ device which can trigger the entire system closing up and protecting itself should clouds roll in, the wind picks up, rain starting, etc.
Re-work / finalize the network gear
- Even with the building being secure on Rusty’s property, I wanted networked cameras and a network video recorder set up so I could see what the scope / roof / flap was doing, as well as keep an eye out for any wildlife that might happen by.
- I also had to provision for internet access to the shed and all its gear. Otherwise, it wouldn’t be “remotely operable” now would it?
Install the telescope pier!
- I ordered an 8 5/8″ pier from Wayne Parker at SkyShed. ( Yes, the bassist for the band Glass Tiger! )
- Wayne was great to work with and was never rushing me off the phone, even after calling him for the 3rd time in a day to satisfy yet another oddball concern I had.
- The pier was produced and delivered well within the timeframe Wayne committed to and arrived in great shape with ample packing.
Install the mount!
- I had a Celestron CGX mount which I purchased while still traveling, but thought it being an ‘observatory class mount’, that it would be fine for completely remote operation.
- I found, however, that it was not quite reliable enough that I was comfortable leaving it across the country and trusting it’d always fire up when I was ready to use it.
- So, I ordered the big daddy of reliable telescope mounts — the AstroPhysics 1100GTO-AE (absolute encoders).
- Believe me when I tell you the AP mounts are at a completely different level compared to any Meade or Celestron setup (and not just the price tag). The quality of craftsmanship and fit and finish is simply amazing.
- The absolute encoders were probably not necessary, but they gave me peace of mind that the mount will always know where it is and can correct for unexpected outside forces (even wind or someone pushing on the scope!)
Installing the scopes and astronomy electronics
- Initially, I affixed my ‘winter’ scope arrangement to the mount:
  - 120mm Skywatcher Esprit with Optec Flip-flat for night time observing
    - Optec FocusBoss digital focus controller
    - FeatherTouch dual speed focuser
    - Skywatcher field flattener
    - Pyxis LE Rotator
    - ZWO OAG
    - ZWO 7 position filter wheel
    - ZWO ASI1600mm-Pro mono camera
  - 60mm Lunt LST60Ha Double Stack solar scope for day time observing
    - Optec FocusBoss digital focus controller
    - FeatherTouch dual speed focuser
    - B1200 blocking filter
    - Celestron 274m mono camera
However, we ended up going back to Rusty’s a short time later. Since galaxy season was upon us, I had the urge for a longer focal length scope for more narrow field deep space objects.
- I found a heck of a deal on a used Planewave CDK 12.5″ scope that already had the DeltaT and Focus controller! ( ~40% off the new price )
- I ordered that in and had it delivered to Rusty’s just before we arrived.
- Off came my winter setup and on went the 12.5″ CDK with
  - MoonLite NiteCrawler WR30 Focuser/Rotator
  - ZWO OAG
  - ZWO 7 position filter wheel
  - ZWO ASI1600mm-Pro mono camera

I know there will be questions about parts that I used. To help with that, here’s a listing of various parts and components that I used in the build, mentioned above or find generally useful in Astronomy.

Note: Where available, I have used affiliate links below. This means if you purchase an item via the links below, we may receive a small commission at no additional expense to you.

2 Comments

Byron · 2019-06-13 at 05:04

I am amazed by this build and setup.
Very well thought out and executed, especially
the power system and remote control as well as weather control setup.
Thank you for a very detailed explanation of your build.
Now, if you would, cost?
Byron

Michael · 2019-06-14 at 05:28

Hello Byron,
Total cost minus scopes and mount is less than $15k. This doesn’t include my (and friends) time building it, nor my time developing the control software. But I consider both of those ‘fun’ and I can’t put a price tag on fun. 🙂

One thing I forgot to mention in the main post is that the entire shed is DC powered. I do have a DC-AC inverter present, but it’s only for my convenience running power tools or charging things while I’m personally at the shed. When I leave, the inverter is powered off. This was one of my driving goals to try and maximize efficiency in the power delivery system by removing the DC->AC->DC conversion losses. There are still some DC-DC converters for various supplies, but their efficiency is much higher than their wall-wart+inverting counterparts.
Michael