Dome de Dome Dome Dooome...

 The last episode had us compacting the gravel and waiting out the rain. This time we had to get the sand into the hole, smooth it, lay the pavers and tamp them down. Then we could begin moving the POD into place.

We went to the local garden supply to get sand. It was cheap and didn't have too many large stones in it. Bonus was that it was outside and pre-wetted for compaction. I sprinkled Amdro ant killer on it before laying pavers. Having a long straight board is important for screeing sand. I was wrestling with a shorter board than I would like to have had. As the pavers were laid I tapped them down with a rubber mallet, since I didn't want to rent the compactor again.

The pavers were purposely laid out so that I could leave a gap for the pier. Not having to cut them was a blessing. Kneeling on the plywood and knee pad worked okay until I could stand on them. Standing on them before there were enough to lock into place would have shifted them too much. It ended up fairly flat so I was pleased. There was a bit of a fall toward the yard for drainage.

Sweeping sand into the cracks meant some broom work. I used fine dry sand from the big box store for this. Two bags did the trick. You can see it in the bottom left corner. My neighbor was out at that point so I convinced him to come over and give Karren and me a hand moving the POD into the new digs. Having more help is mandatory for moving the dome in two pieces. If you quarter the top it might be possible with one person if you have gargantuan arms and strength, but then you must install the weatherstripping off of a ladder. Not good, ask me how I know! I had already sealed it together with silicone so was not willing to take it apart again. I used a 1/2 inch strip of foam weatherstripping on the bottom of the walls to keep out bugs and water - it worked well. You cannot move it around after the foam is in place, so get it where you want it first.

The Skyshed website showed a minimum distance of 114 inches square for the POD with 3 bays, but I found out that it needed a few more inches across. Glad I went a bit wider.

A proud owner after a couple of long days. I got called to work while laying pavers the day before and had to leave things a few times. As long as there are highways there will be people that run over stuff and needs to be fixed... Also, keep in mind that I am 6 feet 5 inches tall and 250 lbs., so I make the POD look smaller than it really is.

Here's a view of the inside showing the pier. Notice I painted the top of the pier where the mount will pivot-- DON'T DO THAT! I had to take it inside and remove the paint. It caused the mount to drag paint around the top, causing a binding action that ruined smooth movement for alignment. I also lubed the top of the rotor with dry lube for even more smoothness.

The electrical is not hot yet but is installed. I did not feel the need to run any signal wires to the observatory because I am wireless to the house router. I am going to cut the tips off the pier through bolts after the summer heat dissipates. Now comes developing a plan for cabinets with drawers in one of the bays for storage. The pier height worked out great (about 36 inches), and can be extended with the bolts if necessary. I like the look of the walnut plate, but am reserving judgement on it until it proves itself. I may have another brake rotor in my future. So just order two rotors if you go this route.

One major problem I ran into was that the elevation knob for the mount contacted the mounting bolts and the brake rotor, so I had to sand off part of the knob. Celestron made it crooked to begin with, so I only had to modify one side. It is an odd thread size (18mm), so I couldn't replace it easily with local parts, and I didn't want to wait for Amazon. Now the mount is easily and smoothly brought into polar alignment with no worries.

Now it is time to shoot some pics! I spent the majority of one night dialing in the polar alignment until I was satisfied with the unguided performance... Okay, I really just sat and revelled in the satisfaction of having my own observatory! Next comes getting the first pics done to evaluate the walnut. I think I will be okay. But then I have to take the mount off for Hypertuning, so check back in a while for the results.

I'll Grovel Not to Have to Shovel Gravel!

 This weekend of the observatory pad saga found me and Karren sacrificing our bad backs to the gravel and sand gods. I spent Friday getting the pier mount finished, cleaning the loose dirt out of the pad area and getting the truck ready to haul material (remove the camper, etc.). I also went shopping for an inexpensive wheel barrow. I'm never going to give another wheelbarrow away! These things are not cheap anymore. After enduring countless harangues from people telling me I should go back and get the one with two wheels ( I use wheelbarrows at work and have had a love/hate relationship for over forty years with them -- if you are interested in what I think about the two wheeled versions contact me...) I found one that would do just fine for well under a hundred bucks. Saturday morning Karren and I got two loader scoops of gravel, about a ton, from our local garden supply. I chose road mix because it has the proper amount of 3/4 stone and smaller fines to compact well. Karren raked it out while I trundled it from the truck.

Then it was off to the Big Box store rental palace to see if we could snag a small plate compactor. Success! A few minutes of walking in circles behind it was all it takes to ensure a properly pounded pad. Karren enjoyed it so much that she was looking for anything else to flatten. The most difficult part of that operation was getting it on and off the truck. ATV ramps and a rope made it easy.

Next step was getting our bedding sand. We went back to the garden supply and loaded just one scoop of sand. Back at the pad I engaged in the endless toil of shoveling into the wheelbarrow and dumping it into the pad while Karren raked it out into an approximately flat surface. It was at this point that we started feeling the brain get feeble. I looked at the time and saw that it was waaaay past our usual feeding time and evening relaxation so we quit for the night. 

The next morning we woke up to constant rain. There is a curse on all astronomers that entails endless clouds after any new astro purchase. I guess that means you pay BIG TIME for a new observatory. Looks like the paver install will have to wait another week. It might take that long to heal from the previous labors.

Maybe I will be able to track down and eliminate the feral rabbit that has taken up residence in our backyard. It is obviously a release from someone's household, as it is about the size of a soccer ball. It has been difficult to get at because of it's tendency to hide under one of our sheds. If it makes one false move toward our garden it will be lights out! Mr. Air Rifle will have to come out and play. I guess a rabbit might be a pretty benign mascot for an observatory as long as it keeps to the clover and grass seed heads. Might have to name the observatory somehow including the poor creature.

Next week: Getting it flat and pavers. Where's a Flat Earther when you need one?

Sod This!

 After researching and checking prices and availability of deck materials I came away with a decision to try another approach. The fact that Lowe’s had concrete pavers on sale for $1.20 made the decision for me. A paved patio will be the POD’s foundation. After checking the measurements around the site location and determining pier height (it’s really a guess) We went to the store and returned with a full pallet of pavers, five pressure treated 4x4x8’s and some hardware. When we were in southwest Idaho I had my mount bolted to a railroad tie pier. It worked so well I decided to try it here, just on a more substantial and laminated wood pier.

With PHD’s in hand (post hole diggers) I dug the hole for the pier about 45 inches deep, which is about as deep as the PHD’s would work efficiently. I figure that is about enough to prevent frost heave here in the Treasure Valley. When digging the hole I kept the sides straight and the loose dirt was all removed.

We chose posts that were from the middle of trees and obtained the straightest ones we could find. The first outside post was drilled on the drill press to provide a sufficient starter hole once it was clamped to the others. Having a good ship auger bit and a very strong half inch drill was critical - don’t skimp if you try this at home. All five were then bolted together with 5/8 galvanized hardware every sixteen inches. I cut the overall length afterward off the bottom with a chain saw - I try not to put this type of lumber through my woodworking saws if I can help it.

Getting this monster off my workbench and into the hole required some leverage and a hand truck. I estimate the trimmed pier to weigh about 150 lbs. Not something to try to handle yourself if you are slight of build or less than robust. I paid for it later that evening. Next we leveled the thing and poured some Sakrete into the hole, mixing with water about every 18 inches. I used a metal rod to plunge into the concrete and eliminate voids and air pockets.

That was enough for day one. I figured we would work on removing the sod over a week or two so as not to kill ourselves. WRONG! The next day I cut the sod layer and Karren hauled it off to stack it nearby. This was expected to be the most labor intensive part of the patio install and it did not disappoint. All my practice at work, leaning on shovels, came into play. It took us about four hours to strip off the sod using a flat shovel. Getting a machine in there would have torn the yard up and been difficult, so our friend Manual Labor had to suffice. Sod sucks to remove by hand, but at least it was drizzling today and the ground was soft. We covered the pier with a trash bag and crawled off to lick our wounds.

In the workshop I hand planed a plank of 8/4 walnut that I have had for about twenty years (can you say “adequately cured?”). I then planed the other side in the power planer and cut the piece I needed off the end.

It was then cut on the band saw to the same circular size as my pier plate, a 2012 Chevy Malibu rear brake rotor, that just happens to fit the bottom of my CGEM DX mount.

Yes, I realize that I am using wood in my observatory pier and that this is considered heresy in the astro world. Most people don’t know how tough virgin 2 inch thick walnut is. I can always replace it with another brake rotor if it doesn’t perform as expected. After rounding over and sanding to make it pretty I drilled the holes in walnut and rotor on the drill press for putting the “rat cage” together. I am going to wait and put the alignment pin hole in the rotor later after I have marked the location by sighting the pole star across it.

So that’s the status at this point. Next we will be installing electrical conduit, adding gravel, leveling, compacting with a plate compactor, adding bedding sand and placing pavers. Just another weekend of relaxation, right? Stay tuned…