Hodgson Observatory

It was a busy day here.

Nancy worked very hard this morning applying a second coat of white paint to the exterior. Dick cleaned everything out of the interior, and vacuumed the interior. Mid-afternoon, working together, we reinstalled the counterweights, coated with white Rustoleum yesterday, on the New Observatory’s arms. Late this afternoon Nancy laid the rubber flooring, trimming it to fit. Wow!  Now we are just about ready for the installation of the 203mm (8-inch) Newtonian telescope. We also need to connect electric power for lighting, the telescope drive, and to supply the needs of a computer.

Many thanks to JJ who came down today (8:40 a.m. to 4:20 p.m.) and helped us fix the balance problem we had with the new observatory’s roof balance. We installed two additional vertical arms on each side of the north end of the observatory roof, each of them carrying 72.5 pounds of weight. The NE and NW horizontal arms additionally are carrying 62.5 pounds of counterbalance weight; the SE and SW horizontal arms are carrying 60 pounds each.

Now the roof sections (both west and east) open smoothly with a maximum assist of about 25 pounds of human effort, and all can be done standing in safety at the north end of the building! It is really a smooth operation.

 

The new observatory here at Sunniside is a monument to our SEAC friends’ construction skills  — and in a lesser way a monument to some of my imperfections as a carpenter. We are looking forward very much to using it as a second observatory, and a place where SEAC members can do some useful observations, particularly for solar disk observing and astro-imaging of nighttime objects. I hope you all will make use of it.

Yesterday Nancy and I had a bit of a scare. I suggested that she might open the west roof “a little” to get a sense of the initial lift required to commence opening. At the time we did not have the 4-foot ladders out on each side to “catch” the roof fully open, so if it opened fully it might easily destroy the hinges. She didn’t hear the words “a little” and pushed down on the NW arm so it went past the point of return pronto. Fortunately I was standing close by and caught the opening roof before any damage was done, but we were frightened. It was like catching a fast-falling 100 pound medicine ball!  I did catch it, and together we closed the roof okay, but it was a struggle for the two of us. Clearly the counter weighting has a way to go. We want sufficiently counterweighted so that maximum human effort should be in the 20 to 25 pound range so that either of us, acting alone, can control opening and closing, and be free to observe there independently if desired. The building and its roof are great accomplishments, but refinement is necessary. Perhaps there is a straight-forward hydraulic solution that could be attached to the corners of the building to slow the opening and closing movements. Alternately, repositioning of and/or adding to the counterweights may provide a solution.  As you think about the problem, here are some relevant facts. The weight of half a roof (i.e., the east or west sections) was probably approximately 160 pounds based on the “weigh-in” of ~ 80 pounds that we made when the arms and counterweights had not yet been added. Add two arms and their current weights of 60 pounds at each of the two corners, and I think we have another ~ 40 + 120 pounds, for a grand total of 320 pounds for each roof section. The trick is to put most of this weight on the hinges, not on the human handler of the roof!

I was awake part of last night thinking about this problem. The hydraulic solution might be the best, but it may be costly. An alternate might involve adding a downward hanging 2×6 branch off the arm at the point where the arm extends out from the building, and extending that branch downward ~ 36″ in length. Put some added weight at the end of this addition, and cross-brace it with the existing arm. Then once the opening of the roof begins that newly added weight will begin to rise, deducting some of the weight the increasingly overhanging roof is producing on the human handler. Perhaps this solution might work; perhaps it would require too much weight for the hinges to hold, and an adult human to handle.We will need to think on this problem, and sleep on it.


At last we had a decent day, dry enough with lower humidity and temperature to permit painting.  This morning Nancy used a roller to paint the exterior of the new observatory with white paint; I painted the difficult to reach spots with a brush. It is good that it is now protected against the weather, although we will put on a second coat of paint to finish the job in the near future. I also got more of the hardware installed today.

We want to thank John and Jim for their generous help yesterday in moving our new Observatory a giant step closer to completion on a second “Saturday Observatory Raising Day”. We deeply appreciate your caring enough to come, and to fix the construction problems my earlier efforts probably generated. The roof is quite a piece of work, and its proper counterweighting, reducing effort to about 20 pounds, will be a priority of ours this week.

We missed yesterday’s showers that hit Sioux Falls, but this morning between 7 and 8 a.m. we had heavy thundershowers that dumped 1.22-inches of rain on us. There was some wind but it was not really strong. The storms have now moved off to the east.I checked the new observatory. The steel roof you guys installed on Saturday did its job. There was NO water inside, so that is quite encouraging. We currently have the western counterweighting arms loaded with 60 pounds weight each, which is in line with the discussion we had with you John before you left Saturday. We shall do more adjusting this afternoon.

On Saturday, August 11, Jim and Anita Morris, John Johnson, and Fernando Nino worked hard helping us put together the walls of the new observatory. In the morning John and Fernando arrived early to square up the lower walls on the 8-foot by 10-foot base and secure them to the concrete. It was an extremely hot, humid day, but we all pressed on hard with the “observatory raising.” Late morning Jim and Anita arrived with additional valuable tools; and after lunch, the work accelerated into the afternoon. By the end of the afternoon the upper walls (for the roof) were also fabricated, ready to put in place. By the end of the work near 6 p.m, the pieces of the roof were brought down to the new observatory site, but there was no time to join them together. They were thus stored inside the walls under a tarp to protect from the weather. (By the way, the whole roof was built as a unit, to be secured in place fully before being sawed into its two halves to permit opening. That separation would not occur until a week later, August 18.) This contribution of labor, tools, and building expertise by Jim, Anita, John & Fernando were very much appreciated. It was a giant step forward for the new observatory.

Later on Saturday, August 11, after a pot luck supper, we enjoyed a clear, starry night of observing.

On Monday morning, August 13, John Johnson returned to help me put in place the four roof walls, connect them together, and then connect roof and lower walls by eight 8-inch T-hinges, four on each side, and drilled and through-bolted them with 5/16ths inch carriage bolts. It is clearly going to be a heavy roof, but the hinges should be sufficient for the task. By late morning it was once again very hot and humid. After lunch John returned to Sioux Falls. Thank you, JJ!

We received the first load of lumber from Schoeneman’s early Tuesday morning. Dick installed the treated 2×4′s for the base around the perimenter of the concrete pad, which is finishing its curing nicely. On Wednesday, he largely finished fabricating the north wall in the garage out of the scorching sun. Today, he put the final door hinges on the north wall, and constructed the west wall and 80%  of the east wall before coming in from the garage about 9:20 p.m., ready to hit the showers. It was sure a hot day! Tomorrow we should have the four walls finished. Most of the roof materials arrived today, although the steel will be coming tomorrow. We are looking forward to Saturday!

This is a brief update on the progress of the new 8 x 10 foot observatory for the 203mm (8-inch) Orion GoTo Newtonian reflector. The concrete, poured last Tuesday, July 31, is curing nicely. Today we ordered the lumber for the walls of the new observatory at Schoeneman Bros. in Hawarden who have handled a lot of our past lumber orders. The lumber will arrive here tomorrow morning, and we shall be working this week to put the walls together. (An order for the roof materials will be placed later this week or early next week.) We have decided to go with 4-foot high plywood walls. On the south wall there will be a 16-inch drop-down panel so the scope can view down to horizontal should conditions permit useful observing that far south (minus 47 degrees declination minus the hill obstruction). The walls are all 5/8ths inch AC exterior plywood with the wall corner supports and hinge supports being 4 x 4-inch timbers. Corners and hinge supports will be bolted together; the plywood will also be connected to the 4 x 4s with heavy screws. There will be 4 large T-hinges on the west wall and 4 on the east wall supporting the roof. A 48″ x 24″ door will be located in the center of the north wall. Two small wall ports, on the east and west walls, can be opened to supply daylight, ventilation, and aid conversation. The roof, which will probably be constructed next week, will slope down to the south. Its sides will be plywood reinforced with 2x6s and 2x4s with 2x2s for rafters supporting white enameled steel with the west side overlapping the east side by about 4 inches. Each corner of the roof will be counterweighted to enable easy opening.