Tales of the Lazy Stargazer

Volume Two, Number Two

The Shpatzir-Mobile

By Alan Rifkin (The Lazy Star Gazer)
Alan@Rifkin.com
www.Rifkin.com

If the mountain won't come to Mohammad, Mohammad will go to the mountain.

A long time ago, I bought a home in the country for dark skies.
I built a backyard roll off roof observatory and enjoyed dark skies for many years, until the corn field next to me was sold and they built McMansions, complete with the only street lights in my town.



I am a member of the Arunah Hill Natural Science Center, which has a very dark sky site in Commington Massachusetts. Unfortunately beside from a bunkhouse and a few great telescopes, it has no facilities.
I drive a van, which I sleep in when camping, but I wanted more amenities for my visits up there.
So I decided to build a miniature mobile observatory.

As often happens in my projects, adding bells and whistles gets the better of me.
The Shpatzir-Mobile, as it is now called, is eight feet long and six and a half feet wide and three and a half feet tall. Besides from an adjustable telescope pier in the middle, it has a battery system and 2 kw. inverter (she wanted enough power to run her hair dryer) for the telescope mount, camera and computers, a WiFi data link to connect the trailer computers to the van's computer where I operate it from, a two burner propane stove, a refrigerator, a Porta-Potty, a gas fired water heater for the hot shower, water tanks large enough to keep me happy for a week, and of course a kitchen sink.

This is the story of putting it all together.
When we visited the Air Stream Trailer Dealer, we found out that one of their gorgeous little trailers would cost us over $65,000, and for that price the tanks were only good for a weekend.
I am handy with tools, a junk collector and cheap.
Time for Plan "B". I figured I could build this for less than the price of my OTA.

I begged, borrow and stole. I hunted junk piles and flea markets and cashed in my collection of Lowe's discount coupons to try and keep the price down.
I also have a machine shop and a good collection of power tools.
I would not take on a project like this without access to lots of tools and a big pile of junk for all the odds and ends and other little pieces a project like this requires.

I have lived in houses, rented RVs, and owned and sailed many boats. Every single one of them has leaked somewhere at some time. You can either drive yourself crazy trying to seal all the leaks, or design it so that leaks are not a problem. I grew up on Long Island Sound and have lots of experience as a sailor and boat builder. From that experience I have learned that eventually everything rots, corrodes or breaks and if the cosmologists are correct, eventually it will all just get sucked into some black hole anyway.

So I built this thing like I would build a leaky boat. I spent extra money to keep corrosion to a minimum, over $100 alone on stainless steel screws and nuts,. All wood surfaces were coated with either epoxy or urethane, and just about everything else is plastic or brass.

Step One, The Trailer
I found my old utility trailer rusting away in the weeds next to the barn. It has been parked there since the last millennium.
I pulled it out, stripped off the old rotten wooden deck, and removed the wheels and old hitch and any other old rusted parts. Bringing it down to a usable frame.



Step Two, Resurrection
I sanded off lots of rust, welded in replacement parts, added support for the telescope pier and connection points for the leveling jack motors. Primed and painted the frame and new parts. I sent out the wheels for new bearing and tires. Added a new hitch, a manual tongue jack, and a new long electrical harness, that can connect to the van even if it is parked fifteen feet away. I sanded and coated the floor with epoxy paint, made out of two 4x8 sheets of " marine plywood. 16" was cut off to make it fit. They were then screwed to the floor beams. Put the wheels back on and then all the other new parts.







Now I was at the point where I would have been if I had started with a new utility trailer, but at the cost.

Step Three, The Wall
The lower walls to be more precise, as the design uses a folding wall design.
Four sheets of " plywood were cut to size, sanded and coated with polyurethane.
They were then attached to the trailer with aluminum angle iron, nylon bars, silicon caulk and Stainless Steel nuts and bolts. Way to many nuts and bolts.



A door was marked out. I then cut one side and attached the hinges. I then cut out the two other sides, and because the hinges were already in place, it was already hanging and the alignment was perfect.



Step Four, Fitting the Cabin
I used the leftover " plywood from the floor to make a counter. It got three coats of urethane. It was bolted to the sides using brackets cut out of 1" aluminum angle. I prefer to cut my own brackets, than use pre-made ones, which I always find to be a compromise. It takes a little longer to make, but they fit better and cost less.



Another sheet of " plywood was cut, sanded, urethaned and made into an equipment locker.
In "Boat Talk" it is called a lazzarette. A piano hinge holds on the top, which makes a fine bunk for those breaks between observing sessions. It got three coats of urethane. The front panel is secured with aluminum angle and stainless screws, so it can be removed to service and install equipment.


Step Five, Plumbing
The $65,000 Air Stream trailer we looked at only had a 20 gallon fresh water tank. It was designed for use as a weekender or at campgrounds where there are hook ups.
At the Winter Star Party, you park for a week and can not move your trailer till it is all over. There are no connections. Twenty gallons for a week is not enough.
I purchased two 35 gallon plastic water tanks. One for White Water (RV talk for drinking water) and the other for Gray Water (RV talk for water that has been used for washing, such as the sink and shower) There is also something called Black Water, which is the water in the porta- pottie.
The two tanks were bolted to the floor in the lazzarette with big rubber shock absorbing washers, along with other assorted hoses and valves, a 12 volt on-demand water pump to supply pressurized water. On the back wall was installed a small propane on-demand hot water heater. Aluminum sheet metal was attached to the wall first for extra-added protection. Not necessary as the heater was designed to hang on a tree, but you never know. It takes two seconds to start to make hot water, and will then make all you want, and is very efficient. PVC pipe was then connected to the sink and shower. All the pipes slant down for drainage to make winterization easy. I don't think I will use the trailer if the temperature is below freezing, but I will definitely take it down south in the winter, then fill it with water once I get to a warmer climate, then drain it before returning north. So I want the procedure to be quick and easy. Just turn off the pumps and open all the valves and all the water drains out the bottom.




A Stainless steel bowl was bolted and sealed to the bottom of the floor. A cut-out in the floor was made above the bowl and a Lexan sheet sits over the hole to keep big things from falling in. The last thing I want is an errant Nagler rolling in for a dunk. I refer to the bowl as the "Bilge" which is boat talk for where all the stuff that leaks in, winds up. A small boat bilge pump and a check valve connect it to the gray water tank. If you wash the floor, take a shower or the rain leaks in, it all goes into the bilge. The propane for the hot water heater is also connected to an old two burner stove set into a covered recess in the counter, it was $25 at the Flea market and included a propane tank, regulator and a free coating of burnt on grease. The stove can be removed and connected with an extension hose for cooking outside of the trailer.
A Thetford porta-potty handles the "other" plumbing needs.

Step Six, Electrical
The electrical system is in multiple sections. The main difference is between 12 Volt DC and 110 volt AC. A 12 volt deep cycle battery is connected through a marine two battery selector switch. Battery two is the battery in the van. Running the observatory, the switch is in the "1" position, to recharge the battery, you start the van, then set the switch to both to recharge the battery. A 2000 watt inverter converts the 12 volts DC in to 110 volts AC, to run the computers, cameras, refrigerator, popcorn maker and Judy's hair dryer. The white water and bilge pumps run off of 12 volts as does the stereo and LED red and white lights. I plan on adding a battery charger for when there is AC power available. The master switch and breaker panel is in the lazzarette.

There are also two electrically operated jacks made out of old linear actuators from a space ship kiddy ride that I use to run in the local mall, they fit into mounts that were welded on to the back of the trailer. Once the trailer is parked, the manual tongue jack is raised; the two linear actuators in back are used to raise and level the trailer, so that is not resting on the wheels, is level, and making for a stiffer observing platform. You don't have to put in quarters anymore to make this ride work.




Step Seven, The Magic Hinges
Most hinges have a range of 180 degrees. My design called for the walls to be in one of three positions covering a range of 270 degrees.
The three positions are: sealed up for travel and storage; folded down for observing; up for camping. To solve the problem, I made polypropylene bars and screwed on two piano hinges. This "Magic Hinge" runs in four sections around the full perimeter and connects the lower wall to the upper wall, allowing it to cover all angles. It was an expensive solution. If you know of a better way, please let me know for the next one of these that I build. Four wing screws connect the walls, and it only takes two minutes to pop them up and secure them.

Step Eight, The upper Walls
The upper walls are connected to the magic hinges. They lock in the up position with four angle brackets. When they are down for travel, they rest on a set of plastic stops set into the top of the lower walls. They have handles on them, which leashes are clipped to, to aid in pulling them up and down. You can have any combination of walls up or down. If the economy continues the easy it's going, in the daytime I may convert this into a hotdog and lemonade stand.

Step Nine, The Roof
The roof is made out of Urethane coated nylon fabric, which snaps on. Fiberglass rods from a tent hold it in shape. It is basically a dome tent that snaps over the top.

Step Ten, fitting the Pier
There are four holes in the middle of the floor. They connect to extra support angle iron that was welded to the frame. The holes are threaded. You set the pier down over the holes and install four wing screws, and the trailer is now an observatory.



I mount the scope on the pier, fire up the computers and WiFi and I am ready to go.
I have one notebook computer in the trailer to run the camera and scope and another in the van to remote control the trailer computer. The trailer stays open to the cold and bugs, while I sit in the comfort of the van to operate it.

Extras
We ran speed tests to 85 mph and one folded down side started to lift in the wind at about 60. Two cinch straps with chafe guards were added for use when towing down the highway. I would not want the sides to open like big wings and to take off like a bird.

I have not listed many little details, like fitting of vents, grommets, routing curves into edges, making a draw, adding racks and a million other small details. Every builder puts in so many small touches, it is impossible to keep track of. You just do it, and forget about it.






Not finished yet
As with any big project, it will never be completely finished.
We plan to add more touches to make it more comfortable and usable. Windows are going to be added, then curtains. There will be a screen door for the bugs. A fan for those hot days when a breeze would be very welcome, for now there is a Coleman tent ceiling fan doing the job. I welded on a trailer receiver on the back. If we need storage more room, a hitch tray or bicycle rack fits in the receiver. When we discover new things we need, I will just think up ways to do it.

What will I do differently next time?
I will admit that building this one was practice for the next one. The first thing I would do differently is use some type of foam core plastic sheets instead of the plywood. I spent about $20 on urethane, sandpaper and brushes on each of the eleven sheets and untold hours sanding and painting, and it is already showing streaks from the metal hinges. So for another five or six hundred dollars, I could avoid all that. I thought of building a box steel frame and using an aluminum skin, but it just gets dented and dinged too easily. Maybe fiberglass sheets would work, but we are talking about a lot more expense and labor, and I hate the exposure to the glass and resin dust. Next I would look for ten foot sheets instead of eight footers. A little more room would be nice. Then I would try to find some type of running plastic hinge to replace the "Magic Hinge" even if I had to still use two runs and have them welded together or to a bar. Finally I want to look at one of the Aluminum frame utility trailers and see if they are stiff enough for this application and if not, could welding in a few stiffeners solve the problem. I am sure the more I use it the more things I will come up with.

Shpatzir?
I am mostly a planetary observer. I love to watch the moons of Jupiter play hide and seek with the planet. Planet means Wonderer, as they wonder around the "Fixed" stars.
The Planet Observatory did not seem like a good name. Shpatzir is the Yiddish term "To wonder aimlessly". I tend to do that a lot, so it seemed like a fitting name. Now the only problem is to teach people how to pronounce it.

What did I forget?
Fill the frig and water tanks.

And now, I am off, traveling to a dark mountain top to observe the wonderers.


All contents © 2008-2010 by Alan Rifkin. All Rights Reserved.