The observatory site is 300 feet from the house, and the Ethernet cable to it from the basement network closet is longer – close to the maxium length specified for Cat-5 cable. Consequently, Mike decided to check if a computer at the observatory site can communicate with the Ethernet switch in the house.
He put connectors on both ends of the cable, then connected it to the switch inside and the computer in the field. Thankfully, the network connection works fine.
At last we've started working on the observatory! Today we cast the 12" concrete pier to hold the telescope mount. We'll build the observatory around the pier, which will be centered east-west but offset 3 feet south of center.
We used our power auger to bore a 16"-diameter hole 28" deep. We rented a concrete mixer, and Mike secured it to the tractor's front-end loader so we could lift and tip it to ease the work. Here it is ready to pour concrete for the footer into the hole.
After the footer concrete set slightly, we placed the 12" tubular form on it and used large wedges cut from 2x4 stock to shim it plumb (second photo below). Then we filled it with concrete. In this case, Louise shoveled the concrete out of the mixer into the form because we didn't want to dump it and risk spilling outside the form.
The pier has a long 12"-diameter base and a 10"-diameter top that is 18" tall. This smaller top will provide extra clearance for the telescope's imaging equipment when pointed high in the sky. The top of the 10" section is four feet above the ground, which made shoveling the concrete into the form a challenge.
The concrete hardened overnight, so Mike took a look at the pier today. The top section appears tilted slightly, but this is a cosmetic flaw only, as the black telescope mounting plate on top can be precisely leveled with hex nuts beneath it.
Mike wrapped the pier with R30 fiberglass insulation to keep the concrete from freezing while it cures completely. After this photo was taken, he draped a tarp over the insulation to shield it from rain.
The concrete pier has cured for nearly three weeks, so today Mike temporaily removed the insulation, then cut and unwrapped the cardboard form around it. He also backfilled the hole around the pier with dirt.
The pier looks pretty good, but the top section has some voids where we didn't stir the wet concrete well enough. These voids don't impair the pier's purpose of supporting 200 pounds of telescope and mounting, but we'll probably patch them later to improve appearance.
Mike replaced the insulation and tarp to allow the concrete to continue curing in cold temperatures.
Ever since we moved into our new house in January 2011, we've been meaning to burn the brush and debris left on the burn pile by the contractor. A couple of weeks ago, we paid a team of workers to clean up debris along the driveway, and take the rubble from the burn pile as well. They took a lot, but left some partially rotted branches and stubble.
Earlier this week Mike clamped pallet forks to the tractor's front-end loader, and used them to carry the leftovers into the woods. Today he used the tractor and landscape rake to drag the rotten wood to the same spot, then smoothed the burn area.
Louise spread grass seed, but weeds are likely to sprout. Either way, Mike will be able to mow this area the same as the rest of the observatory clearing.
Our rural subdivision has a property owners association that must approve any construction, even as minor as our 10' x 14' observatory. The committee met this evening and approved the project based on plans and descriptions we submitted last week.
Now we can buy materials and begin construction (if it ever stops raining).
Calculatons indicate the roof will weigh about 400 pounds, so it's important to know if our garage door opener will move it (if not, we might need to build a smaller observatory).
To test, we secured the opener to a 6x6 post and attached the trolley to a dolly loaded with five 80-pound bags of concrete mix. (The attachment is hidden by the concrete in this photo.)
After a couple of glitches related to the optical obstruction detector (we won't use this, but it must remain connected), the opener moved the 400-pound load in both directions. Now that we're confident it will move the roof, we can start to build.
Today we hitched the trailer to the pickup truck and brought home the lumber and hardware for the foundation and deck framing. We bought:
Updated May 28, 2024