This weekend I assisted at "work party" at the Carr Astronomical Observatory (CAO). Tony was the leader. He brought a long list of things to be done, renovated, repaired, installed, and so on. The Open House is the following weekend...
I went for several reasons, some selfish, some altrustic. Primarily, I wanted to meet more members. I also wanted to see the place, see the observatory and equipment, evaluate it for sky conditions and camping.
the plan
The plan started early in the week.
- Review the CAO "user guide" that Tony had sent.
- Talk to Tony live to find out what to expect, what to bring, etc.
- Book a room at the CAO with Dietmar.
- Get the light box revised with the additional SPST switch (so to control each half of the light box).
- See if I could operate the new MT-1 drive without a formal controller (and if possible get the needed parts).
- Get the M3 car into a driveable state (with the new rims, given the unusual offset).
- Pack astronomy gear (obviously).
- Pack tools needed for CAO projects.
- Pack clothes, toothbrush, etc. for a 2-night stay.
- Do my route planning.
The plan also had me wrapping up the delivery of a 2-day Excel VBA course early on Friday. I wanted to be done by 4:00pm. And out the door at 4:01. Wishful thinking. I was rushing home at 5:00pm after a pretty intense day...
I quickly changed clothes, finished packing, and prepared the car. I decided to skip dinner.
I think, if I remember correctly, I wasn't out the door of my house, heading north, until 6:45pm or so. I knew the predicted drive time was over 2 hours. And I knew the sun would be setting around 8:45pm. If lucky, I would get there while it was still light out. If very lucky the traffic on the 400 would not be terrible. It was for some reason important to me that I make it before dark. With the help of Tony's directions and Ken's GPS, while anxious, I got there during twilight.
deep end
We worked hard on Saturday. First, we unloaded the truck of supplies, tools, furniture, and an ATV. Then we formed a chain gang to unload the interlocking brick. For the rest of the morning David P. and I worked at the large pond cordoning it off. Ian came down later to assist. We ran out of cord so had to halt work.
the pad
When the truck returned with a cubic yard of sand, a group of us began work on the "observing pad." We distributed the sand evenly, "screed" it to the east and to the west, laid fabric, and then started the heavy lifting. We placed 100 patio stones in a 4x25 grid.
The end result of our work is subject to review: unfortunately, some of the stones are wobbling, which won't be good for trying to create a steady view in the eyepiece. I hope that this can be easily rectified. Perhaps watering, the filler sand, and a round or two of vibrating or pounding will help. It would be a shame if we have to lift and replace the patio stones...
solar observing
Ralph set up the Coronado solar telescopes. A "regular" H-alpha Personal Solar Telescope (PST) and a Calcium K line filtered unit. A few of us helped him align it.
The view in the PST was fascinating. You could see granules on the surface of the Sun. The Calcium view, so dim and dark, was much harder for me to make out.
There was a large active sunspot churning away on the northern hemisphere. And there was a small prominence on the top pole!
tire repair
When Tony returned with the truck, he noted that he had a flat tire. The outboard left tire on the dualie seemed to have a puncture. He tried a local shop when heading back into town but found them to be closed. I offered to help.
We searched for a screw or nail at the puncture. Nothing. Maybe it had dislodged. We got some soapy water. Still no sign of the leak. I borrowed Charles's compressor to pump the tire up to full pressure to help spot the leak.
As I fiddled with the air chuck and valve (a bit difficult to reach on the inside of the outer tire), suddenly air rushed out around the valve stem area. At first I thought it was the valve inside the stem. Charles and I looked at each other, rolling our eyes: neither of us had our valve-tightening tool. But as I fiddled with the stem, I realised it wasn't the valve; it was the stem itself! That was a big problem. Tony knew immediately that it could only be repaired from the inside. He was anxious. I thought I would check the inside tire. If low, I could raise the pressure to take some of the burden off the flat tire. It was around 70 pounds (when it was supposed to be 95).
I went about checking all the other tires: they were all around 70 pounds. The outside tire on the other side of the dualie was 60!
It took me a while, with Charles's little compressor (and it's finicky pressure cut-off circuit), to get the tires up to over 90 pounds. I had to keep tricking the compressor.
When Charles grabbed the compressor to use the air tools in the basement, I looked for an incomplete item in the "job jar." I finished the tire pumping the next morning.
red rope
Saturday morning after breakfast, Tony had read from his list of chores, emphasising priority jobs. One job mentioned sounded particularly interesting to me: installing the light rope into the eyepiece cabinet. I was surprised to find this job had not been tackled by late Saturday afternoon. I gathered up the supplies and headed to the observatory building.
The task required installing a 2-metre length of red light rope into the eyepiece cabinet—which is actually a gun cabinet. Costas had done the 120VAC electrical work in preparation for providing the power. He wired up a regular dual socket near the floor beside the gun—err, eyepiece—cabinet with a regular light switch above. I arrived just as he was finished up that job.
The version 1.0 of my design incorporated hanging the light rope in a inverted-U pattern just inside the front "wall" of the cabinet, behind the door's surround. This would keep the rope out of sight while standing in front of the cabinet or while sitting across the room at the computer stations. I affixed the light rope plastic clips to the front of the highest wood shelf and the lowest one, skipping the one in the middle. Meanwhile, Costas created a hole (using a "Greenlee" tool) at the base on the cabinet in the left wall, as a port for the rope or its power cord.
Version 1.1: When I clipped the rope in place, there was some extra length on the floor. We quickly coiled an extra foot or two of rope at the top of the case, forming a ring under the very top of the cabinet box. This provided excellent light to the top shelf; at the same time it emphasised that only a small amount of light was reaching the second and third shelves.
We quickly redesigned to version 2.0 wherein the light rope would be snaked back and forth under each shelf, starting from the ceiling. I relocated the 3 pairs of clips to the bottom edge of each shelf. To hold the rope onto the ceiling of the cabinet, both Costas and I considered a trick with tie wraps. I started feeding the tie wrap from outside the cabinet, around the rope inside, and then back outside through the head. Worked great. A funny effect in the dark with the rope on was that the translucent tie wrap glows red. Now there's good light to each shelf and some extra rope that can snake under a future shelf, if required.
There were some concerns about the light rope being visible while at the computers; this light could be blocked with a valance (2.1?). David P. said he didn't think was an issue: he said he would turn the light on, open the cabinet, grab an eyepiece, close the cabinet, lock it, and turn the light off.
chatted with Leslie
While installing the light rope, Leslie and I had a good chat about education. I told her about my possible astronomy seminars for later in the summer. She offered materials and support. Cool.
height
As I was leaving, I fired up Ken's GPS and read the elevation of the CAO: 451 metres.
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