Construction Updates 5
From Batcountry
See Construction Updates Part 1, Part 2, Part 3, Part 4, Part 5
Here we show Part 5 of our construction process for the first assembly of Bat Country: Generation 3
Click on photos to enlarge.
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Last Minute Preparations
We barely finished preparing for the day's assembly. The last two boxes of bats are finially tightened to 20 ft lbs. (The cones were to be used for support, but we used larger containers instead.) The joints are all assembled and all 1080 bolts are tightened to 5 ft lbs and the 768 holes for threaded rod are reamed smooth. We drilled the softballs, filed each end of the hole (flat and then cone sanded), and used Gorrilla Glue between the the coupling nuts and the softballs. Gorrilla glue foams and expands as it dries, which should be perfect to fill the space between the nuts and balls. Judging by how solid it dried to Gwen's hands, it should work well. Three days later, it still wasn't all off!
The car was loaded with more than 66 bats, 130 joints, 130 balls, 768 nuts, 768 washers, 12 wrenches, thread restoring kit, and a load of other tools. We forgot the ladder. Fortunately, there were others at the site.
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Assembling the Base Layer: 81 Bats
Similar to our assembly for the Gen 2 tetrahedron, we began by assembling the perimeter of the base triangle, and working our way in to smaller and smaller line segments of bats. Once the nuts were finger tight, we lifted the base onto buckets so that our wrenches would have space to work.
Just as with the Gen 2 base, as the base layer is tightened, the triangle becomes flat and rigid, but a bit springy. Once tight, we removed the bucket supports before adding more bats.
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Still at Ground Level
Once the base triangle is tight, we built 27 Gen 0 tetrahedrons, which then turned into 9 Gen 1 tetrahedrons. While the guys with the wrenches were assembling bats, nuts, washers, balls, and joints, other friends were helping us by checking the threads on each bat. Fouled threads were restored with our extra special thread-restoring nut. We kind of wore it out, and could really use a new one. (The size is 1/2-13, in case you've got one lying around you're not using... These thread restorers only seem to come in sets, and they make you buy a whole set of around 50 pieces just for the one nut!)
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27 horizontal bats finished Layer 3. That is a total of 216 bats (out of 384 total). So even though the finished sculpture will stand over 20 feet high, just over half of the sculpture is below eye level. It is very bottom heavy so it wont tip. We mused that even if a large group of people were successful in tipping the sculpture, they might be disappointed to see that it still looks the same. Well, except the orientation of the bats (handles and heads) would be different.
Layer 3 1/2 completes the tops of the Gen 2 tetrahedrons. We pre-welded the six highest load bearing joints on the sculpture. These are the three joints at the top of the Gen 2 tetrahedrons and the 3 in the centers of the horizontal 4-bat spans.
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So far, there is little climbing to assemble the structure. That changes next.
Off the Ground
The next layers were the most challenging part of the assembly. Layer 5 is a Gen 2 Sierpinski triangle, built from the outside in, 10 feet off of the ground. The 4-bat spans were assembled on the ground, with a welded center joint for each 4-bat span. These are most stressed joints on Bat Country.
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We're being watched.
Mark wins the brownie point for restoring that last pesky thread with our fancy, worn, thread restoring nut. Mark requested not to be photographed.
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We assembled the 2-bat spans (with 1 ball and joint) on the ground before we jointed them to the rest of Layer 5. Layer 5 1/2 adds a lot of weight to Layer 5. Since the top section started really sagging, we added a long piece of wood for support. (We are going to use a better scaffold next time.)
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Layer 6 added some stability to Layer 5, but the sculpture still bounces as we work. As the structure gets higher, fewer bats are added on each level, so our crew gets more breaks.
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Layers 5 through 7 went up slowly and carefully. The 2-bat spans of Layer 7 snap the sculpture into shape, and it became rigid. The last bit above that was fast and easy.
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Gen 3 Complete
When the last bolts were tightened, there was a sense of exhileration flowing from the crew. Those at the top all paused for the first time to appreciate the view and hang out.
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Once the workers came down, the children ran up as high as they dared, which was higher than their mother might have liked... "Please, can I just go one higher?" I love the combination of the geometric structure of Bat Country with the organic shape of the human forms, seen from the most unlikely angles. Several people laid in the center to look up from within.
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Bat Country holds many people, and Gwen finally climbs to the top for a photo, well, almost the top.
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This completes Part 5 of Construction Updates.
All images, designs, and text on this site © 2005-2008 Gwen Fisher and/or Paul Brown. Permission required for any capture or reuse.
