Winer Observatory Sonoita Field Station Facility

Winer Observatory Roof Open The Winer robotic observatory in Sonoita, Arizona is designed to hold six telescopes up to one meter in aperture, plus three smaller telescopes for visual observing.

This section of our Web site contains several photos of our Sonoita Facility to help you understand what we provide for your annual fee. The photos are grouped by topic, as listed below. Just click on a group link to get to an associated group of photos. For each of the photos in a group, click on the photo for a larger version of the same image.

Sonoita Facility Building

The Winer Sonoita Facility is located on 21 acres of land near Sonoita, Arizona. The observatory is situated next to the home owned by Mark and Pat Trueblood, making it easy for Mr. Trueblood to support the telescopes of Winer customers.

The building is about 106 ft. long by 26 ft. wide and is divided into two parts: a shop area to the north, 54 ft. long by 26 ft. wide with parapet walls containing the control room, and the observatory area 52 ft. long by 26 ft. wide. The walls are 5 ft. high and the rolloff roof is 8 ft. high, and can clear a telescope 10 ft. high.

Winer Observatory Facility Construction

Winer Observatory West Wall Elevation Winer Observatory Cable holes Counterforts Downspouts

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West Wall Elevation
This shows construction details, including the use of concrete block walls grouted solid with 10-inch steel U-channel inverted on top and held down with J-hooks in the walls. The crane rail upon which the roof rolls is bolted to the channel using hooked bolts.
Cable Holes in the Walls
There are four PVC pipes embedded in holes in the walls -- in each of the east and west building walls, there is one of these in each of the shop walls and each of the observatory walls. These are for passing cables through the concrete block of the walls, which contain rebar and are grouted solid. To keep out insects, the holes are filled with expanding spray foam from an aerosol can. When a new cable is added, the old foam is cleaned out (a bit of a job, as it is quite sticky), the new cable is passed through the PVC liner, and new foam is squirted into the hole.
Shop Wall Counterforts
The first 10 feet of the 15-foot high shop wall is underground. To withstand the consequent overturning moment of the dirt piled against the walls, the structural engineer required counterforts every 64 inches -- piles of additional blocks with four vertical #5 rebars tied every other course around two vertical bars in the walls with a #3 horizontal bar looped through around all six bars. Each wall has a horizontal #5 bar in every other course in bond beam, plus a vertical #5 bar every 24 inches.
Shop Rainwater Scupper Downspouts
The shop roof is suspended between parapet walls, that is, the walls are higher than the roof, to permit the observatory roof to roll unimpeded over the shop roof. The roof slopes one block course (8 inches) from east to west (the side shown in this photo) so that rain water flows westward. Crickets built into the roof channel the water towards four scuppers through the wall into these downspouts. The down spouts empty into a concrete bed that moves the water into a small cistern and into a 4-inch pipe that drains downhill away from the house and observatory.

Top Wall Cooling Pipes Individual Pier Cooling Pipes Exterior Wall Insulation Installation Finished Exterior Walls

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Top Wall Cooling Pipes

Cooling pipes are embedded along the top of the enire east and west walls of the building, including both the shop and observatory. This was done at the time of construction without knowing if they would ever be needed. They are ordinary black steel pipe embedded in the concrete block before it was grouted, with a pipe going in, running along the block, and exiting 8 feet later (8 feet was chosen as it was an integer multiple of the 16-inch length of the block size). The outside of the walls will be insulated with 4 inches of rigid foam, then covered with corrugated sheet steel of the type used on the roof.

Individual Pier Cooling Pipes
Each of the six major piers is encircled by a cooling pipe embedded in the concrete slab. The pipes enter and leave the slab at the nearest exterior wall. As of this time, just as with the wall cooling pipes, there is no water chiller and the pipes are not connected to anything. They had to be installed at the time of building construction before the concrete was poured - adding them later would have been too disruptive, in terms of jack-hammering concrete and creating too much dust while we were trying to observe. So far, we have not seen the need to purchase a chiller and cool the walls or slab.
Exterior Wall Insulation Installation
During the summer of 2002, Winer used a local contractor to install six inches of polyurethane foam insulation on the east, west, and south exterior walls of the shop and observatory. The north wall of the building, which is the north wall of the shop furthest from the observatory facing the house, is coated with stucco to match the nearby house. This insulation not only makes the shop easy to work in during summer and winter, and reduces heating and cooling costs, it should improve seeing in the observatory by reducing the heating of the thermally massive walls of the observatory.
Finished Exterior Observatory Walls

After installation of the polyurethane foam during the summer of 2002 (see above), the installed foam was covered by wood firring strips, then 29 gauge corrugated sheet metal was placed over the firring strips, which keep the sheet metal (heated by the sun) off the foam, and provide a layer of air that also provides some insulation.

Winer Observatory Rolloff Roof Details

Roof rail detail Roof drive system Roof motor U-joint closeup

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Crane Rail Detail
The roof is supported on six double-flanged 8-inch hardened steel wheels that roll on crane rail weighing 25 pounds per yard. The rail is held down to the inverted U-channel on top of the wall by hook bolts that go through holes in the rail. The rail and channel are painted black to increase their thermal emissivity, to help them get rid of heat accumulated during the day more rapidly. In this way, they come to the same temperature as the air and cut down on air currents that damage the seeing. For those contemplating a large roll-off roof, we recommend that you DO NOT use this approach, but instead, use casters on an I-beam to support the weight of the roof, guide the roof in lateral motion, and to hold the roof down in high winds.
Roof Drive System
The rolloff roof consists of a steel structure made with 4"x4" square tubing and 2"x2" cross bracing. The roof is decked with 26 gauge steel and the walls are covered with 29 gauge steel. Two #80 (1-inch pitch) nickel-plated steel chains running near each wall of the building move the roof. The chains are moved by the motor and drive shafts shown here. It takes about 4 minutes to open or close the roof. The Boston Gear worm gear is non-backdriveable, making sure the weight of the roof will not move the motor when power is removed from the motor. The original roof control system is shown here. The photos below show the new control system installed in April 2012. Winer acknowledges the very generous donation by Boston Gear of over $6000 of equipment, including the motor, worm drive, U-joints, pillow blocks, chain, sprockets, and three ACE-I motor inverters.
Roof Motor Detail
The roof is driven by a 2 HP 3-phase motor attached to the Boston Gear worm gear gearbox. The 60:1 worm gear gearbox drives two driveshafts, each with U-joints on each end. The far end of each driveshaft near the walls of the building drive a sprocket on a shaft suspended between two pillow blocks. 110 feet of #80 (1-inch pitch) chain under about 1000 pounds of tension loops over each sprocket on the drive end, and a similar idler sprocket at the opposite (north) end of the shop.
Closeup of a Universal Joint
The takeoff shaft of the gearbox is not at exactly the same height as the shafts holding the sprockets. This requires the use of universal joints (U-joints) at each end of the driveshafts between the gearbox and the sprockets. Shown here is a closeup of a U-joint between the gearbox and the east driveshaft.

North Chain Idler Southwest Wheel Stop Roof control Inside the Roof Control System

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North Chain Idler
The view towards the north shows the chain that moves the roof and the idler assembly and the end of travel. The "shark's fin" or "sail" at the end of the track is a wheel stop that serves as a last resort to stop the roof if the limit switches fail. Chain and sprockets are used to keep the forces on each side of the roof equal and to prevent slippage of the drive system.
Southwest Wheel Stop
This is the wheel stop on the south end of the west rail. If the wheel were to engage the stop, the ACE-I controller is programmed to stop the motor and declare an anomalous condition. If this happens at the north end, it prevents the roof from "going over the edge" and off the track, but it does leave the roof open and the telescopes at the mercy of the elements.
Roof Control System
The Roof Control System is contained in this single box measuring about 2 feet wide by 3 feet high. It consists of a modern motor control system installed in April 2012 by Integrity Controls Corp. of Tucson. Eight limit switches (two in each direction for the south "wall" garage door, and two in each direction for the roof) control the logic to move the roof. A rule built into the system is that the roof does not move unless the south garage door attached to the roof (and forming the south wall of the enclosure) is up. The front touch screen panel controls override the computer when the soft Manual/Auto switch is in the manual position, otherwise they have no effect. Access to the touch screen is password protected. The flexible metal conduits contain various cables, mostly wires from the limit switches and emergency stop switches. Icons on the touch screen indicate when the limit switches are activated. The entire touch screen is echoed in a program running on a computer within the Winer LAN inside the firewall.
Inside the Roof Control System
Due to the extremes of temperature and severe lightning typical at our site, the system uses modern industrial control systems found in factories and other harsh environments. It permits either manual or computer control, and contains a Programmable Logic Controller, Ethernet interfaces, power supplies, a motor contactor to shut off the motor in an emergency, and a variable frequency inverter that converts 240 VAC single phase to 240 VAC 3-phase for the roof motor. The system also opens and closes the south garage door attached to the roof. If the normal limit switches fail to stop the roof, the overtravel limit switches activate the contactor to remove power from the motor, independently of the programming in the PLC.

South Wall (Garage Door) Limit Switches Rolloff Roof Limit Switches Roof Overtravel Limit Switches Roof Tie-Down Chains - Top Roof Tie-Down Chains - Bottom

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South Wall (Garage Door) Limit Switches
The south wall of the observatory is formed by a garage door that must be raised before moving the roof, otherwise the telescopes will be damaged. To tell the roof control logic in the "gray box" whether the garage door is up or down, there are limit switches at each end of travel of the door. For safety, there are two, of different types (mechanical switch and non-contacting), and the logic is wired such that the roof does not move unless both "door UP" switches are closed (activated). If a switch fails, the roof doesn't move, even if the door goes up OK. The black Igus "energy chain" that carries limit switch signals and electric power to the moving roof is seen at the bottom and to the left.
Rolloff Roof Limit Switches
The pairs of limit switches for controlling the rolloff roof are mounted together on the wall separating the shop and observatory. The pair that stop the roof when opening are on the right, while the closing pair are on the left (the non-contacting switch of that pair is mostly hidden).
Roof Overtravel Limit Switches
If the normal limit switches on the east side (shown above) fail to operate properly to stop the roof, the roof will continue to move until it operates one of these overtravel switches (which one depends on the direction of motion; the one on the left if the roof is opening, the one on the right if the roof is closing). When either one of these switches is activated, it interrupts the current to the coil of the magnetic motor starter relay, which snaps open, interrupting any current from the inverter to the roof motor. The roof immediately stops.
Roof Tie-Down Chains - Top
When the weather forecast includes winds over 40 mph, we stay closed and we chain down the roof. Engineering calculations show that, given the area of the roof, the 9-ton roof levitates at a wind speed somewhere around 60-65 mph. The actual speed, given the shape of the roof, is probably somewhat higher, but we are not going to take any chances. If the roof blew off the rails, we would have to remove the siding and cut the roof frame with a torch into pieces, then lift them with a $700/day crane back into place, then weld everything up again and replace the siding, so it would be very expensive to put the roof back on the rails. Instead, we flip the chains you see in this photo over the steel frame into the matching bolt holder.
Roof Tie-Down Chains - Bottom
The chains bolted to the roof tie-downs shown above bolt to the observatory walls at bosses welded to the inverted U-channel that is held down by J-hooks embedded in the grout in the walls of the observatory.

Winer Observatory Control Room

Computer Carts in the Control Room The telescope control room is roughly 18 feet in the east-west direction by 12 feet in the north-south direction. The room is located in the southeast corner of the shop area of facility. The south side of the control room has the carts holding the computers that control the telescopes and the observatory. All cables from the telescopes, their instruments, weather instruments, GPS receivers, etc. terminate here.

Electronics Workbench

ESD Bench This electronics workbench was donated to Winer by Teclab, the leading vendor of such items. This particular bench appeared in a television hospital emergency room series ("Chicago Hope"). Having been loaned by the manufacturer, it was used and no longer in a condition to be sold as new equipment, yet it was in like-new condition. It is a full electrostatic discharge bench, with an ESD work top, sockets to plug in two grounding wrist straps, an ESD mat that is wired into the grounding backplane, and an ESD stool with a grounding chain that drags on the grounding mat. All grounds go to a common grounding point on the back of the bench, which is then tied to a grounding rod driven through the slab 8 feet into the ground.

Machine Shop Overview

ESD Bench ESD Bench ESD Bench

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Workshop: shop floor
The Winer Sonoita Facility has a well-equipped field shop with normal hand and power tools, a Bridgeport milling machine, a YAM gearhead engine lathe, a Delta 14-inch band saw, a Sears Craftsman 2 hp wood-cutting table saw, a Miller MIG welder, and a Lincoln plasma cutter.
Bridgeport Milling Machine
The Bridgeport milling machine was donated to Winer by what was then Hughes Missile Systems (now Raytheon) in Tucson, AZ. This mill has the long knee, a 4-inch riser, optional lube and mister systems, Rapid-Traverse, the 2 hp variable speed head, and a Sony 2-axis digital readout system.
YAM Gearhead Engine Lathe
The YAM gearhead engine lathe was also donated to Winer by Hughes Missile Systems (now Raytheon). All speeds and modes of operation are chosen by shifting levers - there are no belts to move. The motor is rated at 5 h.p. This unit has an automatic cutting fluid sump, foot brake, complete thread cutting speeds, and is a very complete lathe.


Robotic observatories are inherently dangerous to humans. Aside from that, any facility needs safety equipment for the protection of the people who operate and maintain the observatory and the telescopes within it.

ESD Bench ESD Bench ESD Bench ESD Bench

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Carbon Dioxide Extinguisherss
There are two 20-lb carbon dioxide fire extinguishers, one in the shop near the control room and one upstairs in the observatory near the motor and its control electronics. We use carbon dioxide extinguishers due to all the electronic systems in use at the facility. There are also four large red buttons in the observatory, one on each wall, that stop the roof immediately when pressed.
Rainwise WS-2000 Weather Station
Robotic observatories require accurate, reliable weather data. Rainwise generously donated a WS-2000 weather station that obtains its power from a solar panel (to charge an internal battery) and that trasmits the data over a 419 MHz radio link instead of a wire. It has worked reliably day-in, day-out for years, and has survived numerous nearby lightning strikes.
Two ton crane hoist
A working observatory needs a number of tools to support its operations. One of these is an overhead crane or hoist to lift crated items delivered from trucks at our rear gate (that is at semi-trailer height) to the appropriate spot on the observatory floor. At that point, the crate can be dismantled without disrupting ongoing operations, and the contents can be lifted into place. The hoist rides on a dolly that slides east-west on an I-beam spanning the entire roof width, and moving the roof using the manual controls (including a Jog button) covers the north-south axis.
GPS Antenna
Accurate system time is important for both robotic observatories and telescopes. An error of only one second of time is 15 arc seconds on the sky in potential pointing error. Relying only on Internet time updates at a remote site such as ours could leave your telescope observing the inside of our roof during daylight hours. Furthermore, we would not want to open our roof during the daytime, exposing your telescope to the full fury of the midday sun, then fail to open the roof at night. The Air Force Global Positioning System (GPS) can provide time accurate to 0.5 microsecond.

ESD Bench ESD Bench ESD Bench

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Cable trough covers
When the observatory slab was poured, metal forms were placed in the slab to produce cable troughs in the concrete. The forms were shaped to have a shoulder for a cover plate. During the summer of 2001, Greg Peisert of the Miami Valley Astronomical Society assisted our Director in producing and installing metal cable trough covers formed of 1/8-inch diamond plate steel with a "ladder" of 3/4-inch square steel tubing welded to the underside to add stiffness.
Cable trough covers open
A cover is shown removed to indicate the generous size of the Winer cable troughs, which have adequate capacity to supply all telescope piers.
Cleaning Telescope Optics with CO2 snow
Each month, Winer staff clean the exposed optics of all telescopes in our Observatory using CO2 snow generated using aparatus purchased from Richard R. Zito Corporation of Tucson, AZ, the leading supplier of such equipment to the world's top observatories (Keck, IRTF, Gemini, etc.). The monthly period was chosen based on a paper presented at the August 2002 SPIE conference in Kona, HI.

Page last updated on: December 6, 2013