Construction of the Dome
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The parts of the dome are sorted and waiting for assembly. Without a real manual I can't even be certain that I have everything. I was told it's complete but building it is the only real way to confirm it. The more I study the parts and the Ash dome manual, the more convinced I become that stuff is missing. Besides hardware, I think I may be missing spacers for the panels and tracks. And I think I'm missing tracks for the rolling shutter wheels.
I'm also beginning to believe this dome has never been fully assembled. I don't see any holes around the top of the base ring to attach the dome panels. And of course the dome panels are new uncut panels with no base mounting holes in them either. |
Building a metal dome like this is something I've never done before and I'm really scratching my head over it. I also haven't figured out yet why I have a two piece sliding shutter plus a drop-down door. It seems to be one piece too many, but I'll see what goes where when I get to measuring to cut the aperture opening.
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The base sections and wheel tracks were sorted and temporarily bolted together, so I can get accurate measurements. The diameter measures 150" or 12' 6". Now that it's confirmed I can proceed with building the base ring for the dome rollers.
The Ash Dome manual says their 12'6" dome weighs in at a bit over one thousand pounds, which means once the dome is permanently bolted together I'd need heavy equipment to lift it, if I don't build it on top of the building. |
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The observatory building is nearly ready so it's time to start figuring up how much new dome hardware is needed. Counting up all the years the dome has been stored by myself, the person I bought it from, and the factory, it has to be somewhere around 25 years, and a lot of the zinc-plated and even some galvanized hardware is now oxidized or just plain rusted.
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Rusty hardware cannot be used on the galvalume dome panels. It will cause them to rust for certain, so I have to order new stuff. It's going to cost several hundred dollars, but there's really no choice if I want the dome to last.
I've already ordered 600 stainless bolts and 600 new nuts, plus 400 rubber and nylon washers so far. I may not need every single bolt ordered but I have to order in quantities of usually 50 to 100 each to get a better price or to get it at all. I may only use 90 out of a 100 of something, but it's still cheaper buying prepackaged quantities. There's a lot of miscellaneous stuff, too. The photo is just some of it.
I've already ordered 600 stainless bolts and 600 new nuts, plus 400 rubber and nylon washers so far. I may not need every single bolt ordered but I have to order in quantities of usually 50 to 100 each to get a better price or to get it at all. I may only use 90 out of a 100 of something, but it's still cheaper buying prepackaged quantities. There's a lot of miscellaneous stuff, too. The photo is just some of it.
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There are 104 clips for connecting dome panels together. They are zinc coated and a lot of them have oxidation, too. Since Lancaster is now out of business, I don't know if it's even possible to buy new clips, but I can't use these as-is on the Galvalume, so I cleaned all 104 and sprayed them with cold galvanizing compound.
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Lancaster used galvanized garage door hinges for the dome wheels, and after 25 years these are also heavily oxidized. I could buy new ones, however the hinges sit on rubber cushions and the cushions are punched to fit the hinge hole pattern, and this pattern does not match present day hinges. Go figure. So all 23 of these were also cleaned and sprayed with cold galvanizing compound.
I was also missing several of the rubber cushions, so I had to order some 1/4" thick neoprene rubber and cut replacements. |
The dome skirt, shutter doors, and tracks are all galvanized steel and still in good condition, but most of the hardware for assembling the base, the gear track and the roller tracks is missing, so I ordered new stainless hardware. There's probably other hardware missing that I'll have to order as I go.
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The dome rotates on 23 garage door rollers. These were missing so I went the extra expense of ordering commercial car wash door rollers. They are 3-inch (2-3/4") diameter polyethylene, sealed bearing, 4-1/2" stainless steel shaft rollers meant to survive wet environmental conditions. And these wheels are much quieter than metal wheels. They are much higher quality than residential garage door rollers and should provide many years of trouble-free operation.
The first issue I ran into with the base rollers is the wheels rubbing on the track's mounting bolt heads, so I ordered flat head, (hurricane or sidewalk head) screws to replace the domed truss head bolts. |
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There were some 2" shutter rollers Included, but they're rusty so I ordered nylon, sealed bearing rollers with 6-1/2" zinc-plated stems. Not quite as high quality as the stainless steel dome rollers, but still much better quality, and quieter, than the standard residential garage door rollers. The only problem now is it appears the tracks for these wheels is missing, or there's something I'm not understanding yet about the shutter parts I have.
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Two pieces of the aperture frame were damaged by the previous owner. Both pieces were bent out shape as shown in the top down and side views in the photos.
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It took a bit of "shade tree mechanic" work to straighten them, but the radius looks pretty good now.
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And this is the shade tree that did most of the work. Since I didn't have anyone to help, and I don't have any kind of sheet metal bending tools, I had to get creative. The notch of the twin hickories was used to torque the pieces back into shape, along with a little hammering on a saw horse.
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These are all the parts I have for the shutter aperture, except the door and the rolling shutter itself.
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Five of the six pieces to the dome base are finally on the wall. I need to leave the sixth piece off until I have finished all work around the wall top roller plate.
Mounting the base has revealed an error on my part reading the Ash dome drawings and calculating the building and top plate diameter. The diameter of the top wall roller plate is slightly too big which is causing the horizontal bottom edge of the dome roller track to rub in places against the top plate. To correct it I had to trim down the plate, which took several days of work, but now everything is spinning freely.
Mounting the base has revealed an error on my part reading the Ash dome drawings and calculating the building and top plate diameter. The diameter of the top wall roller plate is slightly too big which is causing the horizontal bottom edge of the dome roller track to rub in places against the top plate. To correct it I had to trim down the plate, which took several days of work, but now everything is spinning freely.
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After finishing some caulking, repainting the edge of the top plate, and greasing all the wheel shafts, the last section of the dome base was installed. The first five pieces slipped onto the rollers without needing to be disassembled, but to get the sixth piece on, I had to remove the wheel track and mount it in place first, then slip the panel in place and rebolt it to the track. I've also installed all new stainless steel hardware on the completed base. I'm now at the point of test fitting dome sections.
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Lancaster built architectural and silo domes and the dome panels attach to a center ring at the top. This ring gets cut out when cutting the shutter opening.
I have a manual on how to assemble a silo dome, but mounting the dome sections at the bottom is a bit different on this base. It's also obvious that this base has never had panels installed on it because there aren't any mounting holes. There is a front and back to the base of the Ash dome. There appears to be a cutout in the front and it's all pre-drilled, but on my base I can't see any real difference between sections, they are all the same except one, which has a short filler section attached. Nothing is pre-drilled for the panels so I guess I can do it anyway I want. I hate guessing. |
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This is a day I've been looking forward to for a looong time. I'm finally installing dome panels. The first day was half preparation and half installing panels, and with my wife's help eight dome panels were installed. One more full day and all the panels should be on.
The individual panels are not very heavy and I can lift them into place while my wife makes sure the top is lined up. Then we slip the panels together, drill the base hole, and connect the sections with a 5/16" bolt and nylon washer at the bottom, and 1/4" carriage bolts, rubber washers, and clips along the seam.
The top's center ring is temporarily blocked up on the 10' ladder. After a number of panels are connected it becomes self supporting and the blocking can be removed.
The individual panels are not very heavy and I can lift them into place while my wife makes sure the top is lined up. Then we slip the panels together, drill the base hole, and connect the sections with a 5/16" bolt and nylon washer at the bottom, and 1/4" carriage bolts, rubber washers, and clips along the seam.
The top's center ring is temporarily blocked up on the 10' ladder. After a number of panels are connected it becomes self supporting and the blocking can be removed.
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We tried to finish the panels on the second day but didn't make it. The dome now has 21 panels installed, with 4 more to go.
By the time we had finished working on the dome for the day, it was getting dark and my wife spotted a train of Starlink satellites heading South-Southeast. They were still close together and very bright, fading in and out as they rotated in the sunlight (I assume). This was on Friday, Sept 6.
By the time we had finished working on the dome for the day, it was getting dark and my wife spotted a train of Starlink satellites heading South-Southeast. They were still close together and very bright, fading in and out as they rotated in the sunlight (I assume). This was on Friday, Sept 6.
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All the panels are now installed. There are 25 panels forming the dome, with an open space for two more, but that's where the shutter opening will be cut.
I originally thought I had enough clips to connect all the panels together, but I am short a total of 17 clips. I'm not sure where I can buy them since Lancaster is out of business. |
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In my search for the missing roof panel clips for the dome, I discovered there is a silo builder called Virginia Silo in Harrisonburg, VA, about an hour-and-a-half away. They were very helpful folks and actually had some of the clips leftover from other silo builds. They just gave them to me, so now I have the 17 missing clips plus a few spares. I'm just waiting on another bag of stainless steel carriage bolts to arrive so I can install them.
This new dome is huge inside compared to my old 8' Exploradome. There's room for several people in here at a time, and plenty of room to work around the pier and scope. That's a 10' stepladder in the picture for size comparison. This dome will be a dream come true if I can ever get it finished. |
Now I really need to figure out how the shutter tracks were supposed to go together, because I'm definitely missing some parts that I'll have to make. Since I don't know for sure just how closely Lancaster copied Ash on these, I'm just going to follow the Ash manual that I have, and make the tracks match the manual as closely as I can.
I spoke to a metal fabrication shop that said they can make some of the missing parts, but I've hit a wall on the 2" garage door tracks for the shutter rollers. No one I've spoken with says they can bend those. They all tell me the same thing, they don't have the necessary dies to do it and they buy them pre-bent. So there's some guy over in China that can bend these, but not here. I guess I'm going to have to work on a way to do it myself.
After talking with several metal fabricators, it's looking like it's going to cost me something like $1000.00 just to make the missing flashing trim for the aperture opening. And I still have to find a way to bend the garage door tracks. This is looking to be a major setback. And these are not the only parts I'm missing, just the most crucial ones that I can't live without. One thing is for sure, I'm not going to get the dome finished by the end of 2024.
I spoke to a metal fabrication shop that said they can make some of the missing parts, but I've hit a wall on the 2" garage door tracks for the shutter rollers. No one I've spoken with says they can bend those. They all tell me the same thing, they don't have the necessary dies to do it and they buy them pre-bent. So there's some guy over in China that can bend these, but not here. I guess I'm going to have to work on a way to do it myself.
After talking with several metal fabricators, it's looking like it's going to cost me something like $1000.00 just to make the missing flashing trim for the aperture opening. And I still have to find a way to bend the garage door tracks. This is looking to be a major setback. And these are not the only parts I'm missing, just the most crucial ones that I can't live without. One thing is for sure, I'm not going to get the dome finished by the end of 2024.
Since it's going to be a while before I can even consider getting the missing parts made, I've decided to just move on and finish the concrete pier base and the interior of the building in the mean time. That work is on the "Building The New Observatory" page.
more to come...
Page created 12/20/2019
Last update 11/23/2024
Last update 11/23/2024
