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Fairhavens II


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Fairhavens II

My last article was an overview of Fairhavens, my first dedicated observatory, along with its untimely demise.  It is now five years later and I am ready to try again.  As is revealed in my first article, the wife and I had to move back into town (Tucson) as a result of a medical problem (Kidney transplant) that required she be closer to a hospital, and a legion of doctors.  She is much better now and, other than a wheelchair, is destined for a normal life, albeit in the aforementioned town.

I have downsized my new astrophotography gear to a Celestron AVX mount with an Orion 8” Ritchey Chretien telescope.  Because of my own problems (I am really old and bent) I needed to find a way to permanently mount my gear outside.  BTW, my favorite quote is by Keith Richards (You old guys remember him) when he said, “If I’d a known I was gonna’ live this long I woulda’ taken better care of my body!”.  So, the search began.  The ground in the backyard of my rented home was not a typical hard-baked smooth adobe typical of Arizona surface, but rather a mix of gravel, rocks, weeds, and bugs.

Being a rental home I could not build a permanent structure (I couldn’t afford one anyway).  So, I started looking for a temporary structure that would protect my gear from the elements and still leave room to move about.  First place I always go is Cloudy Nights classifieds and looked under Observatories.  Of course, anything I could have used was already sold.  I then went to Amazon and found this gem.

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SpaceAstronomy.com

It became a candidate when I found the price to be less than $300.  Planning began in earnest and I bought it sight-unseen.  My planning was no different than pretty much all of my previous projects, the key word being ADAPT!

As is typical of unimproved Arizona dirt there was the attendant population of “Goatheads”.  For those not initiated, a goathead is a disgusting little weed seed that consisted of a tiny ball populated by an abundance of spikes sticking out.  They gleefully stick to the soles of your shoes only to be easily dislodged in your carpet.  The simplest (cheapest) way to form a barrier is “Pea gravel”.

I decided to dig a foundation to contain the gravel during our Monsoon rains here in Arizona and started the digging.  The depth of the walkway was determined by the hardness of the dirt.

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The tent dome was eight feet in diameter and had four entry doors.  For a few consecutive nights I stood in the backyard like a Do-Do bird at night with my eyes about telescope level to locate the center of the eight-foot diameter tent and drove a spike into the ground to mark the center.

I then marked a three-foot walkway from the back patio to the edge of the eight- foot scribed tent footprint and began digging.

 

In case I had not mentioned previously, I was a Psych Major so had little or no math background.  That, by the way, was a bit of a hindrance. During my years working in the Mirror Lab at Steward Observatory I gained the rudiments.  I took my two-dimensional sketches to the local landscape yard and had them calculate how much gravel I would need at three inched deep.  It worked out to be about one and a half tons.  Seemed like a lot to me but I figured if it were too much I could find somewhere else to use it.

I thought that digging the walkway and eight-foot circle was a big enough problem until a large dump-truck showed up and vomited a stack of pea gravel on my driveway.  Umm, how do I get it to the back yard?  Ace Hardware is only a few blocks distant, so I ran down there and bought a flat-nosed shovel and the cheapest wheelbarrow they had.  At that point it still had not occurred to me exactly who was going to pilot the wheelbarrow.  At that moment the light went on over my head and I remembered that my thirty-five year-old son was living with me temporarily!

 

 

 

 

 

 

 

He is a great asset in many ways.  But having spent a substantial amount of time in Iraq as a Light Infantryman, his back was not in great shape.  So, between the both of us, it took a few hours to move and level the gravel.

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I was beginning to smell victory at this point.  Actually it was just Tylenol.  The work ended long before the day and we retired to the den with ice water, a ceiling fan, a couple of Tylenol and a wide-screen TV.

DAY II

It was time now to start assembling the observatory tent.  The floor of the tent was heavy fabric but still needed to be protected from the pointed feet of the mount.  Back to ACE where I bought three concrete fence caps to use for protecting the mount feet from puncturing the tent floor by sinking into the pea gravel.

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I took my AVX mount outside and positioned it facing magnetic north using my cell phone.  After getting it positioned, I slid the blocks under the legs and removed the mount.   I scribed the position of each block and dug the pea gravel down to the hard earth and replaced the blocks while smoothing the pea gravel back to the edge of the blocks.  I was now ready to install the tent.  Since the tent has four access openings it was easy to orient the floor.

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As you can see, I marked the position of each foundation block with yellow duct tape before placing the AVX mount inside the tent.  From this view we are looking south with east to the left.  Since east is my target area, I placed the tent facing this direction.  As I mentioned previously, the stakes that came with the tent are the usual short aluminum sort that will work on wet lawn, but certainly not on desert dirt so I went back to Ace Hardware and bought a box of 12-inch-long heavy nails which worked perfectly.  It was now time to start populating the tent.

 

 

 

 

 

As is evident, there is plenty of room for both the mount and the RC telescope.  This structure will easily fit an 8 -inch f/4 reflector as well.  The small table in the background supports my laptop, Ipad, and cases to store cameras in when not in use.

The Orion 8-inch RC height is adjusted to clear the edges of the tent walls so I have access to the east from nearly the horizon to the north and to the south.

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The roof of the tent is a cap that is held in place by both velcro and nylon straps.  It takes about five minutes to remove or replace the roof.  Two days after finishing the project we had a late Monsoon storm roll through.  There were high winds, lightening, and horizontal rain.  The structure held up perfectly with no leaks or damage of any kind.

The total cost for the whole project was $450 and about a gallon of sweat (Arizona heat; it’s a dry heat)


  • nightowl, Bob Campbell, JMP and 34 others like this


37 Comments

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ChrisCharlesJax
Nov 11 2021 04:05 PM

I really appreciate this write up. My local astronomy club has this product (donated by the same vendor as we are 30 miles north of them in Jacksonville, FL) as the top prize for our Astrophotography contest, which I am hoping to win *fingers crossed*. I've wanted one of these for years to use down at the Winter Star Party to avoid the occasional high winds that they see in February in the Keys. I am happy to see that there is room in the tent to set up a laptop on a table. It looks like just what I need.

Congrats, Pat, and a happy Veterans Day to you and your son!

    • Bob Campbell likes this

Hi

Great article.  My first use of this was in January and February 2020 at Rusty's RV ranch outside of Rodeo New Mexico.  I was there almost two full months and experienced some cold nights, and amazing wind storms, up to 60 mph gusts.  The tent held up fine.  Since the wind storm was over a few days I learned quickly that simple stakes just don't cut it, even 12" stakes (you may get away with it because your backyard wall take a brunt of that wind, my setup didn't have anything blocking).  The wind pulsating will slowly work those stakes out, no matter how fancy they are ( the best was the pet leash holder that has a large screw shaft).  So something heavy enough on top of the stakes, 10lbs or more size rocks kept them in place.  Definately strange weather these days.

 

Pray for Clear Dark Skies, keep looking up :)

    • Bob Campbell and Mike McShan like this

Great write up and I think you will like the tent. I am going into my second full winter with this tent in a semi permanent set up, using it in the winter and switching to a reflective cover in the summer. It works a treat, my home is at the top of a hill in the Sierra Nevada foothills and the tent has withstood the full brunt of our winter storms without issue. Mine came with the perimeter stakes as well as 4 guy lines, with the guy lines secured to large boulders and the stakes well secured I have not had any pull out or any issues with the tent itself. It has some definite sun fading on the fabric and it feels a touch brittle after nearly 2 years of use but no tears or visible damage so far. All in all a good purchase for anyone needing a portable solution or unable to install a permanent structure.  

But here's my question:  when the wind is blowing, let's say, 20 mph with gusts, does the tent provide adequate shelter from the wind such that the scopes are not vibrating and one could do astrophotography?

 

I ask because recently I went to NM for the November new moon, and 3 out of four nights were too windy/gusty for PHD2 to guide my mount.  A temporary wind shelter would be a great boon.  

Neat article, great idea!  The years will pass quickly.  You may want to consider exploring if you can pull a blue or silver tarp over the tent and stake down during the day, especially for times you know you won't be imaging/observing for more than a couple of days.  Consider the tarp to be expendable, as I would expect over time the UV rays from the Sun will first fade, then start to destroy the tent material.  I don't believe that nylon material is expected to live out in the Sun 7x24x365.  

    • Transit likes this
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Mike McShan
Nov 17 2021 05:21 PM

A great story and well told. I hope that you have many clear nights to enjoy your new observatory and that you and your wife do well.

But here's my question:  when the wind is blowing, let's say, 20 mph with gusts, does the tent provide adequate shelter from the wind such that the scopes are not vibrating and one could do astrophotography?

 

I ask because recently I went to NM for the November new moon, and 3 out of four nights were too windy/gusty for PHD2 to guide my mount.  A temporary wind shelter would be a great boon.  

In terms of durability and protection for somewhat more harsh conditions I think something like the Octans Portable Observatory may be more suitable. But really even at 20 mph, I'm not certain if I'd be imaging as I'd expect turbulent winds would affect seeing.

    • Oyaji likes this

Great read thanks! I like your humour :)

Great article, really love the setup. I may consider to invest a tent like this ^_^

This article came at some great timing. I've been spending the past couple of days trying to find something like this to have my scope "permanently" outside but also avoiding the direct sunlight (even with the cover, that doesn't help much). As asked above, where did you grab this? I can't seem to find it on Amazon.

 

Also - did it come with the floor tarp or did you buy that separately? 

  It is a concrete floor that I poured over some scrap fencing for extra support to the concrete. I made the floor over bare dirt and only 1.5 inches thick to hole my weight, there's a 3inch gap between floor and concrete pier to reduce vibration. Antrader Flange Mounted 5/8" Ball Transfer Unit Bearings are the Amazon bearing I ordered and you get plenty.Hope this helps.

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nikulsuthar
Nov 29 2021 11:44 PM

Great idea and great setup indeed... One question though... Do you think to keep your setup out in this tent during Arizona summer heat? I live in North Phoenix and looking to the summer heat and temperatures in the afternoon, I doubt that I can leave the setup and such a tent outside all the time...



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