Domes in the Default World
Domes in the Default World
For a quick boost of Playagy yesterday, I went out and sat in the top level of my triple dome "snowman" structure, cracked a beer and smelled the playa dust on the groundcloths....It's 5 degrees here in Michigan, and the domes's under two feet of snow. Anyone else playing in their structures at home?
Howdy From Kalamazoo
Re: Domes in the Default World
Heh, yeah, I confess. <g>
Fabbed the struts for a new 30' dia 5/8 3f dome between solstice & full moon in preparation for the unofficial "Merced Burning Man" event in Merced, CA on Jan 10.
Played around with perturbing the bottom hexagons to make the doorways taller. Worked great using 1" conduit with the doorways almost 7 feet high (92 inch struts for these).
We consecrated the uncovered dome with fire dancing inside as a "Bush" monkey was burned in effigy outside, all to the passionate Gypsy Kings' Tiera Gitana CD. Much dancing; lots of tequila; too much; very hard to climb the ladder 19 feet the next day to take things back apart.
Now playing around with new coverings, like gluing heavy duty foil between two sheets of heavy duty white tarp. Test strips came out great. Totally opaque, VERY reflective (heh, got so close to the space heater I melted the tarp off the near side of the test strip and still didn't feel any heat on my hand up against the other side), and the thickness really cuts down on flap noise. Downsides include dramatically increased fab time, not sure how best to glue large pieces, and repeated crumpling and rumpling of the test strip causes minor but unsightly tears in the foil. Still testing. Suggestions welcome.
Do you have some pics of your snowman structure? Any enhancements planned for 2004?
Fabbed the struts for a new 30' dia 5/8 3f dome between solstice & full moon in preparation for the unofficial "Merced Burning Man" event in Merced, CA on Jan 10.
Played around with perturbing the bottom hexagons to make the doorways taller. Worked great using 1" conduit with the doorways almost 7 feet high (92 inch struts for these).
We consecrated the uncovered dome with fire dancing inside as a "Bush" monkey was burned in effigy outside, all to the passionate Gypsy Kings' Tiera Gitana CD. Much dancing; lots of tequila; too much; very hard to climb the ladder 19 feet the next day to take things back apart.
Now playing around with new coverings, like gluing heavy duty foil between two sheets of heavy duty white tarp. Test strips came out great. Totally opaque, VERY reflective (heh, got so close to the space heater I melted the tarp off the near side of the test strip and still didn't feel any heat on my hand up against the other side), and the thickness really cuts down on flap noise. Downsides include dramatically increased fab time, not sure how best to glue large pieces, and repeated crumpling and rumpling of the test strip causes minor but unsightly tears in the foil. Still testing. Suggestions welcome.
Do you have some pics of your snowman structure? Any enhancements planned for 2004?
"Yes, but is it art?" "No, Art is over there, on the couch."
I was planning on taking some pix of the frost and snow on the domes, to use as "mental air conditioning" on-Playa...I'll get 'em up....You're about the first person that I've heard mention tweaking the dimensions of the struts, which is how I horsed the three domes of the Snowman together! I've only made 2v domes up until now, but a big 3v is on my mind for next.....We pulled a trailer out west last year but are probably flying in '04, so I'm trying to design a smallish version of the Snowman that will fit into stowed luggage. (seems like most airlines have about the same regs, 62" and 70 lbs., times two...just about right!) Either that or rent a van in Reno, hit a lumberyard and build a wooden version that we can toast on site, sans hardware and covering of course.....
Howdy From Kalamazoo
Getting things to the playa
Hmmm, another thought might be to try and find someone in Reno or thereabouts to whom you could drop ship your materials, then pick them up using the rented van. Just a thought, haven't researched.
How tall is the Snowman? And how do you put it together?
I used two 20 foot extension ladders for the first assembly, but even with outriggers things were a bit wobbly at the top.
I am now researching building a hoist, like the one pictured here:
http://www.lee-anne.com/bm03/playa/pages/brastrax.htm
(thanks to lee-anne and the magicglasses team for that photo!).
We'll still need the ladders to do the covering & such, but it seems like a hoist would keep most of the tricky assembly more or less at ground level. Thoughts on this?
How tall is the Snowman? And how do you put it together?
I used two 20 foot extension ladders for the first assembly, but even with outriggers things were a bit wobbly at the top.
I am now researching building a hoist, like the one pictured here:
http://www.lee-anne.com/bm03/playa/pages/brastrax.htm
(thanks to lee-anne and the magicglasses team for that photo!).
We'll still need the ladders to do the covering & such, but it seems like a hoist would keep most of the tricky assembly more or less at ground level. Thoughts on this?
"Yes, but is it art?" "No, Art is over there, on the couch."
I built the Snowman in sections, starting with the base (about 20' dia. 2v)-Most of that was doable from ground level plus stepladder. Then there's a deck composed of nine struts that radiate from the polar vertex to nine of the ten equatorial vertices of the secondary dome. (about 12'dia.) The deck struts have lengths of 2"x4" clamped to them with conduit clips. To these supports is nailed the decking, which looks like a pentagonal picnic table with a wedge missing...(ladder hole!) With the wood nailed down, you then have a secure platform from which to assemble the topmost sections. On-Playa the top was a tall cone consisting of 5 long struts that converged in a point with a blinkybeacon- That was removed and replaced with the Snowman's clear plastic head, which now sports a comfy "geodesic web" of woven rope that hangs from the five top vertices of dome 2...(there is no center, polar vertex in dome 2- those struts were removed after many painful skull bonks, and since the top dome is designed to support only itself, everything's plenty strong without them!)
I'm so satisfied with the web idea that I think I'll remove the wooden deck entirely- the space is airier and brighter without it. I'm studying spiderwebs to design a tubular ladder that can be incorporated into the web-decks for added support. DESIRED END RESULT: A multi-dome structure that consists solely of conduit, woven rope and plastic (eventually fabric) covers, that breaks down small enough for two people to put in their stowed baggage on a commercial flight....ESTIMATED CURRENT SUCCESS RATE: 80% complete.
I HAVE researched shipping the whole mess out there- Can't explain logically why I don't feel confident doing so......
I'll try to get some good shots of this weird hulk over the weekend and get 'em online.....
I'm so satisfied with the web idea that I think I'll remove the wooden deck entirely- the space is airier and brighter without it. I'm studying spiderwebs to design a tubular ladder that can be incorporated into the web-decks for added support. DESIRED END RESULT: A multi-dome structure that consists solely of conduit, woven rope and plastic (eventually fabric) covers, that breaks down small enough for two people to put in their stowed baggage on a commercial flight....ESTIMATED CURRENT SUCCESS RATE: 80% complete.
I HAVE researched shipping the whole mess out there- Can't explain logically why I don't feel confident doing so......
I'll try to get some good shots of this weird hulk over the weekend and get 'em online.....
Howdy From Kalamazoo
Oh, wow, you may just be my new hero! Your Snowman sounds way cool. Can't wait to see pictures and hope you can get it out to the playa in 2004.
A web is also on my list to investigate. I even built the lower struts of the upper hexagons out of 1" conduit to take the load of a platform at that level (but see from your other posts those may not be necessary; thanks!).
I tried to price cargo webbing; wow, too pricey. Am now looking at one of those cheap trampolines, like:
http://www.jumpsport.com/pr-1240.htm
http://extextoys.com/8rountram.html
And then maybe use ratcheting tie-downs like these:
http://doityourself.com/store/gp28650.htm
to secure to the vertices (I have seen these at Costco for much less; more like $15 for 4). Not sure I would use the springs of the trampoline, though, as the goal is more observation/sleeping platform than jumping experience (the dome vertex is right around 19 feet and the middle of the upper hexagon is around 14.5, making that more of an observation platform implementation; the tops of the lower hexagons are around 11 feet; still only 8 feet max clearance). Much left to ponder.
So, very interested to hear more about your web building/testing.
Re the glue. Looks like 3M Spray Adhesive 77 works the best. Sprays on evenly (mighty noxious stuff, though) and adheres to both the foil and the tarp without any degreasing/priming. Seems to last OK without drying out so far, but I have only been testing the one strip for a few days. Pretty much putting it through hell, though; it spent yesterday in the pool. Except for the minor tears from crumpling and rumpling it seems to be holding up well. My big fear is going to all the effort to custom sew the polygons with this setup (major labor and very taxing even on my commercial sewing machine) and then having the stuff delaminate and look crappy. Promising so far.
I also tried 3M 90, the Super Strong stuff; for some reason it delaminated quickly (and never held all that well to begin with), and it didn't spray on evenly, so it is out.
And for grins I tried epoxy (not sure of the actual brand, but the kind that mixes up kind of milky yellow-white). Didn't work well at all. Wouldn't stick to the tarp, too firm, hard to make an even coating, blah, blah, blah. Guess I could have used degreaser and a pre-bonding agent for plastic, but why bother when the 3M 77 looks more promising?
Cans of 3M 77 are about $10 from HD and 1 can will coat 220 sq ft, or about 1 hexagon.
Now thinking about cool designs of panels with/without the foil, as an all foil dome would be way too dark. Probably only do the southern facing sections (maybe 3 out of 5) to block the major rays.
Great discussion; thanks for the exchange!
A web is also on my list to investigate. I even built the lower struts of the upper hexagons out of 1" conduit to take the load of a platform at that level (but see from your other posts those may not be necessary; thanks!).
I tried to price cargo webbing; wow, too pricey. Am now looking at one of those cheap trampolines, like:
http://www.jumpsport.com/pr-1240.htm
http://extextoys.com/8rountram.html
And then maybe use ratcheting tie-downs like these:
http://doityourself.com/store/gp28650.htm
to secure to the vertices (I have seen these at Costco for much less; more like $15 for 4). Not sure I would use the springs of the trampoline, though, as the goal is more observation/sleeping platform than jumping experience (the dome vertex is right around 19 feet and the middle of the upper hexagon is around 14.5, making that more of an observation platform implementation; the tops of the lower hexagons are around 11 feet; still only 8 feet max clearance). Much left to ponder.
So, very interested to hear more about your web building/testing.
Re the glue. Looks like 3M Spray Adhesive 77 works the best. Sprays on evenly (mighty noxious stuff, though) and adheres to both the foil and the tarp without any degreasing/priming. Seems to last OK without drying out so far, but I have only been testing the one strip for a few days. Pretty much putting it through hell, though; it spent yesterday in the pool. Except for the minor tears from crumpling and rumpling it seems to be holding up well. My big fear is going to all the effort to custom sew the polygons with this setup (major labor and very taxing even on my commercial sewing machine) and then having the stuff delaminate and look crappy. Promising so far.
I also tried 3M 90, the Super Strong stuff; for some reason it delaminated quickly (and never held all that well to begin with), and it didn't spray on evenly, so it is out.
And for grins I tried epoxy (not sure of the actual brand, but the kind that mixes up kind of milky yellow-white). Didn't work well at all. Wouldn't stick to the tarp, too firm, hard to make an even coating, blah, blah, blah. Guess I could have used degreaser and a pre-bonding agent for plastic, but why bother when the 3M 77 looks more promising?
Cans of 3M 77 are about $10 from HD and 1 can will coat 220 sq ft, or about 1 hexagon.
Now thinking about cool designs of panels with/without the foil, as an all foil dome would be way too dark. Probably only do the southern facing sections (maybe 3 out of 5) to block the major rays.
Great discussion; thanks for the exchange!
"Yes, but is it art?" "No, Art is over there, on the couch."
I think we're getting some great cross-pollination going here!
-That 3M stuff shore 'nuff is wicked! Have you given any thought to SEWING the layers together? (lots o' work, granted, and I haven't had the chutzpa to sew a custom Snowman cover yet...)
-I, too, have considered a trampoline! Obviously it would be a big draw at BRC, if it were stabilized to the extent that you could bounce on it! How about a "crow's nest " or loft that you could ONLY bounce up to?!?
-The geoweb designs that I'm developing for the loft are based on patterns for fishing nets- I found a wonderful book on knots (The Morrow Guide to Knots- ISBN 0-688-01226-4, Quill Publishing) that was the inspiration for the whole thing...The idea is to have a web at least tightly-woven enough to act as a safety net , and ideally small enough that you'd have to work to get your foot through it...there would be SUPER tight areas (the knot book calls 'em "plats") that would serve as seating, a place to put objects down, sound footing while assembling the dome, etc.-
Maybe wooden panels or boards could be worked in to add rigidity...This whole big mess would be strung from ten points at "second floor" level, and additional support would come from vertical lines down from the five vertices of the "roof". At worst, you're likely to spill your cocktail the instant that anyone moves anywhere on or in the web, but at BEST it'd be a light, airy, fun thing to climb around in/snooze on/swing from!
-Back to panels- I cut up silver tarps and customed panels with grommets for almost all of the sections, for the Playa incarnation of the Snowman. These little sections offered shade, but let the big wind gusts just slip on through....they were all zipstripped down, and adjusted with spring clamps. Perhaps a modular system would work for you, with triangles and/or pentagons and hexagons that could be moved around to provide shade as needed.....
-That 3M stuff shore 'nuff is wicked! Have you given any thought to SEWING the layers together? (lots o' work, granted, and I haven't had the chutzpa to sew a custom Snowman cover yet...)
-I, too, have considered a trampoline! Obviously it would be a big draw at BRC, if it were stabilized to the extent that you could bounce on it! How about a "crow's nest " or loft that you could ONLY bounce up to?!?
-The geoweb designs that I'm developing for the loft are based on patterns for fishing nets- I found a wonderful book on knots (The Morrow Guide to Knots- ISBN 0-688-01226-4, Quill Publishing) that was the inspiration for the whole thing...The idea is to have a web at least tightly-woven enough to act as a safety net , and ideally small enough that you'd have to work to get your foot through it...there would be SUPER tight areas (the knot book calls 'em "plats") that would serve as seating, a place to put objects down, sound footing while assembling the dome, etc.-
Maybe wooden panels or boards could be worked in to add rigidity...This whole big mess would be strung from ten points at "second floor" level, and additional support would come from vertical lines down from the five vertices of the "roof". At worst, you're likely to spill your cocktail the instant that anyone moves anywhere on or in the web, but at BEST it'd be a light, airy, fun thing to climb around in/snooze on/swing from!
-Back to panels- I cut up silver tarps and customed panels with grommets for almost all of the sections, for the Playa incarnation of the Snowman. These little sections offered shade, but let the big wind gusts just slip on through....they were all zipstripped down, and adjusted with spring clamps. Perhaps a modular system would work for you, with triangles and/or pentagons and hexagons that could be moved around to provide shade as needed.....
Howdy From Kalamazoo
Heh, yeah, we're obsessed allright <g>, but what fun, eh?
Great stuff on your web plan. Sounds like a real labor of love; lots of knots, but also lots of opportunity to make a really artistic design. I look forward to hearing/seeing more as that progresses. What kind of rope do you think will work best for that? Same stuff as used for higher end hammocks?
Re sewing the tarp/foil, I tried quilting it, but it cuts the foil too much and doesn't quiet the tarp down during flapping (kind of adds a nice raspy top note, though). The glue approach seems the best so far, I just have to do the work outside.
My plan is to make separate covering pieces for each of the polygons (6 pentagons, 10 full hexagons and 5 half hexagons at the bottom).
I have made one pentagonal covering piece out of single ply tarp cut from triangles & sewn together and it fits nicely (plus the seams on the inside buffer the tarp from the struts so the wear should be mnimal), but it lets in too much light against the full sun for my taste.
Attachment to the dome is via 3" lengths of 1" nylon strapping used to make loops sewn every couple of feet around the edge (well, actually about 3 inches from the edge, to give room for overlap with the next piece); these loops hold ball bungees that then wrap around the struts (or maybe the strut and the next covering piece, kind of like stitching the covering together and onto the dome; but I gotta get another piece built first to test this out).
At this point I plan to make one full hexagon out of tarp/foil to see how it goes. Probably cut two rectangles large enough to cut the 6 triangles from and then glue foil onto one and then the second layer of tarp onto that before cutting out the triangles.
If this goes well I will probably make a total of 6 hexagons (3 upper & 3 lower), two pentagons and two half hexagons. out of tarp/foil, with the remainder of singly ply tarp. This will make around 60% of the cover opaque to turn toward the sun, with the rest single ply to let in enough ambient light from the north.
Looks like my themecampmates (is that a word?) are going to group up for a "sew-in" in mid-February, so I want to have the design tested and ready to go for them by then.
Thanks for sharing that shingling the covering works well to shed wind & heat, as I was curious about that. I have an idea for a retractable top pentagon to help shed heat, as well. Basically, loops of rope are run through an eye bolt in the top vertex and then knotted on either side of a grommet in the corners of the top pentagonal covering piece. The loops of rope then act as drawstrings to pull the covering toward the center or toward the edges.
I'll let you know if I pursue the trampoline idea (probably not until late spring) as your knot book reference might be just the ticket to make runners to reduce the 84 D-rings around the 14 foot trampoline to 10 or 15 attachments to fit the vertices.
Oh, say, on that note, here's a design question that has been bugging me that you have probably answered already. It is basically, "What are the right attachment points for a platform in the middle of a dome?"
If we look at a dome diagram, like this:
http://www.desertdomes.com/pics/dome/3vdiagram2.gif (Thanks Tara!)
I am thinking of attaching the trampoline to either:
a) the tops of the lower hexagons (where the B struts run between the pentagons), which is 10 attachment points, or
b) to the centers of the upper hexagons (where the C struts all come together), which is 5 attachment points.
Let's consider case A first. If I attach just to the tops of the lower hexagons, that will transfer load to the pentagons, yes? Assuming that those 10 attachment points bear the majority of load in any case, would it be wise to then add straps (not necessarily load bearing) from the trampoline to the centers of the pentagons to keep them from pushing out too far and letting the load bering attachment points invert?
Or should I make all 15 vertices (the tops of the lower hexagons AND the centers of the pentagons) load bearing? I am reluctant to do this because I fear it would warp the trampoline too much and make it uncomfortable.
Another alternative might be to run load beariing straps between adjacent pentagon centers, resulting in a pentagon of straps a few inches below the plane of the trampoline (but well out of the way as the trampoline is only 14 feet diameter and would be centered within the dome).
A similar "uneven plane" problem is present if I attach to the centers of the 5 upper hexagons. In this case I am concerned that some reinforcement of the vertices at the top of the pentagons (the B-C-B-C-B-A vertices) might be needed to prevent inversion of the hexagon centers (the "all-C" vertices).
Got any thoughts on that?
Oh, and I need to 'fess up on the doorway perturbation idea. It wasn't mine; I lifted it from here:
http://dome.zillabit.com/geometry.html (Thanks Earl!)
They came out really well, though. Plenty of shoulder room for the 6 footers on the team and wide enough at waist level to move ice chests & furniture in and out easily.
Great stuff on your web plan. Sounds like a real labor of love; lots of knots, but also lots of opportunity to make a really artistic design. I look forward to hearing/seeing more as that progresses. What kind of rope do you think will work best for that? Same stuff as used for higher end hammocks?
Re sewing the tarp/foil, I tried quilting it, but it cuts the foil too much and doesn't quiet the tarp down during flapping (kind of adds a nice raspy top note, though). The glue approach seems the best so far, I just have to do the work outside.
My plan is to make separate covering pieces for each of the polygons (6 pentagons, 10 full hexagons and 5 half hexagons at the bottom).
I have made one pentagonal covering piece out of single ply tarp cut from triangles & sewn together and it fits nicely (plus the seams on the inside buffer the tarp from the struts so the wear should be mnimal), but it lets in too much light against the full sun for my taste.
Attachment to the dome is via 3" lengths of 1" nylon strapping used to make loops sewn every couple of feet around the edge (well, actually about 3 inches from the edge, to give room for overlap with the next piece); these loops hold ball bungees that then wrap around the struts (or maybe the strut and the next covering piece, kind of like stitching the covering together and onto the dome; but I gotta get another piece built first to test this out).
At this point I plan to make one full hexagon out of tarp/foil to see how it goes. Probably cut two rectangles large enough to cut the 6 triangles from and then glue foil onto one and then the second layer of tarp onto that before cutting out the triangles.
If this goes well I will probably make a total of 6 hexagons (3 upper & 3 lower), two pentagons and two half hexagons. out of tarp/foil, with the remainder of singly ply tarp. This will make around 60% of the cover opaque to turn toward the sun, with the rest single ply to let in enough ambient light from the north.
Looks like my themecampmates (is that a word?) are going to group up for a "sew-in" in mid-February, so I want to have the design tested and ready to go for them by then.
Thanks for sharing that shingling the covering works well to shed wind & heat, as I was curious about that. I have an idea for a retractable top pentagon to help shed heat, as well. Basically, loops of rope are run through an eye bolt in the top vertex and then knotted on either side of a grommet in the corners of the top pentagonal covering piece. The loops of rope then act as drawstrings to pull the covering toward the center or toward the edges.
I'll let you know if I pursue the trampoline idea (probably not until late spring) as your knot book reference might be just the ticket to make runners to reduce the 84 D-rings around the 14 foot trampoline to 10 or 15 attachments to fit the vertices.
Oh, say, on that note, here's a design question that has been bugging me that you have probably answered already. It is basically, "What are the right attachment points for a platform in the middle of a dome?"
If we look at a dome diagram, like this:
http://www.desertdomes.com/pics/dome/3vdiagram2.gif (Thanks Tara!)
I am thinking of attaching the trampoline to either:
a) the tops of the lower hexagons (where the B struts run between the pentagons), which is 10 attachment points, or
b) to the centers of the upper hexagons (where the C struts all come together), which is 5 attachment points.
Let's consider case A first. If I attach just to the tops of the lower hexagons, that will transfer load to the pentagons, yes? Assuming that those 10 attachment points bear the majority of load in any case, would it be wise to then add straps (not necessarily load bearing) from the trampoline to the centers of the pentagons to keep them from pushing out too far and letting the load bering attachment points invert?
Or should I make all 15 vertices (the tops of the lower hexagons AND the centers of the pentagons) load bearing? I am reluctant to do this because I fear it would warp the trampoline too much and make it uncomfortable.
Another alternative might be to run load beariing straps between adjacent pentagon centers, resulting in a pentagon of straps a few inches below the plane of the trampoline (but well out of the way as the trampoline is only 14 feet diameter and would be centered within the dome).
A similar "uneven plane" problem is present if I attach to the centers of the 5 upper hexagons. In this case I am concerned that some reinforcement of the vertices at the top of the pentagons (the B-C-B-C-B-A vertices) might be needed to prevent inversion of the hexagon centers (the "all-C" vertices).
Got any thoughts on that?
Oh, and I need to 'fess up on the doorway perturbation idea. It wasn't mine; I lifted it from here:
http://dome.zillabit.com/geometry.html (Thanks Earl!)
They came out really well, though. Plenty of shoulder room for the 6 footers on the team and wide enough at waist level to move ice chests & furniture in and out easily.
"Yes, but is it art?" "No, Art is over there, on the couch."
Dman!
Not sure about the ideal rigging for that platform- Until recently, I've only hung rigid or semirigid platforms and when I do it's from the ten...The geodesic web in the top of the Snowman hangs from the five, but it's fairly small...MORE seems like it'd be BETTER, generally...
The rope that I use is 1/2" nylon rope from the surplus store, ten bucks for a hundred feet- Even a small web eats a LOT of rope! I'm considering going even larger, as unless the web is closely woven the smaller the strand the more it "bites"... I learned the hard way that you have to attach the web to the dome with 'biners or something that you can remove. Much easier. (you can get heavyduty links that screw shut, kinda like cheap carabiners, in the chain section at the hardware store.) Anywhere that I plan to hang a hammock or web I install an eyelet instead of a bolt, and then 'biner to that. You can swap a bolt out for an eyelet by clamping down on all of the flattened strut-ends with vicegrips and then wiggling the bolt out. I use this technique when joining two domes together, too...it's easier to deal with two semirigid structures than a bunch of loose, swinging struts. Another handy discovery was those mountainclimbing couplers that consist of two carabiners joined by nylon webbing- they're great for hanging around vertices where a hookeye is absent!
......I took pix thhis weekend, and then forgot to take my workbag with me this morning so I'm without the disc and (gasp) my thermos of coffee! Maybe tomorrow......
Not sure about the ideal rigging for that platform- Until recently, I've only hung rigid or semirigid platforms and when I do it's from the ten...The geodesic web in the top of the Snowman hangs from the five, but it's fairly small...MORE seems like it'd be BETTER, generally...
The rope that I use is 1/2" nylon rope from the surplus store, ten bucks for a hundred feet- Even a small web eats a LOT of rope! I'm considering going even larger, as unless the web is closely woven the smaller the strand the more it "bites"... I learned the hard way that you have to attach the web to the dome with 'biners or something that you can remove. Much easier. (you can get heavyduty links that screw shut, kinda like cheap carabiners, in the chain section at the hardware store.) Anywhere that I plan to hang a hammock or web I install an eyelet instead of a bolt, and then 'biner to that. You can swap a bolt out for an eyelet by clamping down on all of the flattened strut-ends with vicegrips and then wiggling the bolt out. I use this technique when joining two domes together, too...it's easier to deal with two semirigid structures than a bunch of loose, swinging struts. Another handy discovery was those mountainclimbing couplers that consist of two carabiners joined by nylon webbing- they're great for hanging around vertices where a hookeye is absent!
......I took pix thhis weekend, and then forgot to take my workbag with me this morning so I'm without the disc and (gasp) my thermos of coffee! Maybe tomorrow......
Howdy From Kalamazoo
(three hours later) ...I have found coffee, and my brain is running again...(impulse power only) I was drawing out some designs for the trampoline problem, and it occurred to me: Support from the 10 AND the 15, either from ALL of the points or alternating.....the two axes of support would stabilize the 'tramp.
I wouldn't worry too much about the hexes inverting, especially with the stress shared out over a dozen locations give or take.
I wouldn't worry too much about the hexes inverting, especially with the stress shared out over a dozen locations give or take.
Howdy From Kalamazoo
Hey, great that you should bring up eye-bolts, as I have been testing those out, as well, so thanks for recommending them. And I'll definitely pick up a few of the screw links that you recommend (I use those on trailer safety chains all the time, but didn't think to use for dome).
I am a big fan of using the "Trucker's Hitch" to tie rope off nearly every where it needs to be taut, and eye bolts & screw links will be perfect for that.
FWIW, I also plan to use eye-bolts around the bottom perimeter (in this location the eye will be pointed outward) to hold the rebar. I figure a 4" eye-bolt will give the appropriate clearance for pounding the rebar, as I would like to use a hoist to assemble from top down and that means I can't really pound the rebar until the bottom layer is in place and the dome is on the ground.
When assembling the eye-bolts so far I have used an extra nut & washer up against the eye to separate the eye from the conduit. This lets me adjust the amount of the bolt that protrudes from the other side of the dome to keep it from rubbing the covering as much, but....
this brings up a strength question. Have you done any testing of the strength of the "typical" 3/8 eye-bolts from the local Home Despot (the kind where the shaft is just bent around to make the loop)? They say they are good for a few hundred pounds of load, but even then only parallel to the bolt.
So, if I want to, say, hang a hammock (almost perpendicular to the bolt from most locations), and especially if I use the "extra nut" approach outlined above, at what load do I need to be concerned about the lateral rigidity of the bolt? I guess I should test this (shouldn't be too hard), but any real life experience you have to share would be welcome.
I looked into the "real" eye-bolts (the kind with a solidly forged eye) and those are way too pricey for me (like $20 a pop rather than < $1 for the HD kind), so if the bent eye-bolts aren't strong enough for perpendicular things then I plan to use webbing to create attachment points (probably using the screw links you recommended; way cool, thanks!).
Re attachment points, back in December I built a scale model dome ala the recommendations from Tara, here:
http://www.desertdomes.com/faq.html
I now plan to put it back together after I get the covering design finished (dome sewing circle confab in only three weeks and I am busy the next two weekends helping friends move; sometimes it sucks to be the owner of a truck <g>). I will then test out the different attachment point approaches by building a model platform suspended by string and then hanging a weight from various points to see "what gives".
I will try to get some pictures up someplace, as well.
Lotsa fun!
I am a big fan of using the "Trucker's Hitch" to tie rope off nearly every where it needs to be taut, and eye bolts & screw links will be perfect for that.
FWIW, I also plan to use eye-bolts around the bottom perimeter (in this location the eye will be pointed outward) to hold the rebar. I figure a 4" eye-bolt will give the appropriate clearance for pounding the rebar, as I would like to use a hoist to assemble from top down and that means I can't really pound the rebar until the bottom layer is in place and the dome is on the ground.
When assembling the eye-bolts so far I have used an extra nut & washer up against the eye to separate the eye from the conduit. This lets me adjust the amount of the bolt that protrudes from the other side of the dome to keep it from rubbing the covering as much, but....
this brings up a strength question. Have you done any testing of the strength of the "typical" 3/8 eye-bolts from the local Home Despot (the kind where the shaft is just bent around to make the loop)? They say they are good for a few hundred pounds of load, but even then only parallel to the bolt.
So, if I want to, say, hang a hammock (almost perpendicular to the bolt from most locations), and especially if I use the "extra nut" approach outlined above, at what load do I need to be concerned about the lateral rigidity of the bolt? I guess I should test this (shouldn't be too hard), but any real life experience you have to share would be welcome.
I looked into the "real" eye-bolts (the kind with a solidly forged eye) and those are way too pricey for me (like $20 a pop rather than < $1 for the HD kind), so if the bent eye-bolts aren't strong enough for perpendicular things then I plan to use webbing to create attachment points (probably using the screw links you recommended; way cool, thanks!).
Re attachment points, back in December I built a scale model dome ala the recommendations from Tara, here:
http://www.desertdomes.com/faq.html
I now plan to put it back together after I get the covering design finished (dome sewing circle confab in only three weeks and I am busy the next two weekends helping friends move; sometimes it sucks to be the owner of a truck <g>). I will then test out the different attachment point approaches by building a model platform suspended by string and then hanging a weight from various points to see "what gives".
I will try to get some pictures up someplace, as well.
Lotsa fun!
"Yes, but is it art?" "No, Art is over there, on the couch."
Cool! How big was your model? I've made tabletop models just to help me visualize.
As far as eyebolts go, I try to use as large and heavy as will fit through my boltholes- I use 3/8" bolts, and bore out my strut holes to 1/2" for easy assembly- I try to avoid any blatantly harsh lateral strain and make sure that all loads are at least partially shared at all times, and have never had one even BEND, not to mention fail.
My approach to mounting them is to screw a nut ALL THE WAY on, even tightening it with a wrench, so it won't rotate. Then BIG washers (half-dollar sized) on both sides and a nut. Depending on the location, I either use a shorter thread or locate where it won't poke the cover, but it's an imperfect system. I also always orient the eyelets so they're vertical, thinking that that will somehow reduce the lat shear. Seeing as it works, perhaps I'm right.....
I always keep an extra, long-threaded eyebolt handy as a "comealong" if I'm making that last vertex connection and things won't behave...Usually you can work the eyelet in, tighten the whole mess down, clamp it with vicegrips and replace the eyelet with a bolt.
IDEA! Wecould round up a bunch of domeheads and start a themecamp where we experiment with geodesic shapes on-playa.....
As far as eyebolts go, I try to use as large and heavy as will fit through my boltholes- I use 3/8" bolts, and bore out my strut holes to 1/2" for easy assembly- I try to avoid any blatantly harsh lateral strain and make sure that all loads are at least partially shared at all times, and have never had one even BEND, not to mention fail.
My approach to mounting them is to screw a nut ALL THE WAY on, even tightening it with a wrench, so it won't rotate. Then BIG washers (half-dollar sized) on both sides and a nut. Depending on the location, I either use a shorter thread or locate where it won't poke the cover, but it's an imperfect system. I also always orient the eyelets so they're vertical, thinking that that will somehow reduce the lat shear. Seeing as it works, perhaps I'm right.....
I always keep an extra, long-threaded eyebolt handy as a "comealong" if I'm making that last vertex connection and things won't behave...Usually you can work the eyelet in, tighten the whole mess down, clamp it with vicegrips and replace the eyelet with a bolt.
IDEA! Wecould round up a bunch of domeheads and start a themecamp where we experiment with geodesic shapes on-playa.....
Howdy From Kalamazoo
The model is a 12" radius 5/8 3v, made with 1/8" wooden dowling and 1/8" ID plastic tubing bits held together with tiny machine bolts (2-10?) & washers (ah! my poor eyes!). All the dowel pieces have painted ends (tip; don't do that, as the paint just gets the pieces stuck in the tubing; paint an inch or so away from the end).
I made it 12" because at one point I thought I wanted a 24' diameter dome (1/12 scale). So, when it was all done and I decided I wanted a 30' dome instead I had to go find little dolls that were only 4.5-5" tall so they would fit the scale rather than the 5-6" dolls my kids already had laying around.
Heh, I even started making custom covering pieces out of plastic tablecloth to see how the shingling would work.
It's really cute. Really. But, does this speak obsession, or what?
I'll take & post a few pictures when I assemble it to do the platform stress testing (end of February).
Major thanks for the tip on using an eye-bolt as a comealong. Fumbling with and dropping those hex head 2.5" 3/8 bolts as we repeatedly reassembled the vertices to add struts was easily the most frustrating part of the assembly. A big fat ring to hang onto (and maybe even attach to a bit of cord with the other end tied to the tool belt) will make things SO much easier the next time around.
And I am definitely up for some type of domehead gathering at Vault of Heaven. Can't do a theme camp this time around as half the reason for the dome is to put some shade on my the butts of my nekkid niece & her friends, but I definitely want to gift you a few beers and swap stories!
How about if we try to get some type of "dome tour" going, where interested domeheads can visit each other's structures to get the inside story? Anybody already do that before? I see we're getting a few views of this thread. Anyone else interested? Heck, I might even be willing to host a gathering some afternoon (like happy hour on Tuesday; show your Vise grips & barked up fingers to get in! <g>).
I made it 12" because at one point I thought I wanted a 24' diameter dome (1/12 scale). So, when it was all done and I decided I wanted a 30' dome instead I had to go find little dolls that were only 4.5-5" tall so they would fit the scale rather than the 5-6" dolls my kids already had laying around.
Heh, I even started making custom covering pieces out of plastic tablecloth to see how the shingling would work.
It's really cute. Really. But, does this speak obsession, or what?
I'll take & post a few pictures when I assemble it to do the platform stress testing (end of February).
Major thanks for the tip on using an eye-bolt as a comealong. Fumbling with and dropping those hex head 2.5" 3/8 bolts as we repeatedly reassembled the vertices to add struts was easily the most frustrating part of the assembly. A big fat ring to hang onto (and maybe even attach to a bit of cord with the other end tied to the tool belt) will make things SO much easier the next time around.
And I am definitely up for some type of domehead gathering at Vault of Heaven. Can't do a theme camp this time around as half the reason for the dome is to put some shade on my the butts of my nekkid niece & her friends, but I definitely want to gift you a few beers and swap stories!
How about if we try to get some type of "dome tour" going, where interested domeheads can visit each other's structures to get the inside story? Anybody already do that before? I see we're getting a few views of this thread. Anyone else interested? Heck, I might even be willing to host a gathering some afternoon (like happy hour on Tuesday; show your Vise grips & barked up fingers to get in! <g>).
"Yes, but is it art?" "No, Art is over there, on the couch."
Oh, I just went back & reread your message on using the 10 AND the 15 vertices for the trampoline. Great idea; distribute the load more and allow compensation between the differing heights of the vertices! Cool! Thanks! Definitely one to test.
"Yes, but is it art?" "No, Art is over there, on the couch."
Okay, I can't post the pics from here. I can email them to anyone who gives me an address, but they're not so fabulous, really.
After discussing models, I'm convinced that someone's going to have to create a BRC-friendly playset for making models of themecamps and structures...."LarryLogs"? "Erectile Set"? You can buy magnetic kits for making little geodesic structures, and there are some REALLY cool Hoberman toys, but I'd love to just find some scale components with which to make lil' domes.....I know, I know, MAKE 'EM. Oh, all right.
After discussing models, I'm convinced that someone's going to have to create a BRC-friendly playset for making models of themecamps and structures...."LarryLogs"? "Erectile Set"? You can buy magnetic kits for making little geodesic structures, and there are some REALLY cool Hoberman toys, but I'd love to just find some scale components with which to make lil' domes.....I know, I know, MAKE 'EM. Oh, all right.
Howdy From Kalamazoo
Erectile sets....
Yeah, I looked around for building blocks and found a few that were "educational", but didn't find any that fulfilled all my criteria:
1) Scale model in the frequencies I wanted (3v, 4v, 5v).
2) Useable for stress testing (the magnetic sets move around way too much).
3) Very compact & who cares if it gets a bit bent or broken, or a few parts wander off (not like those damn Lego model kits where one teeny little missing part under the couch can bring a fun time to a grinding halt! Hmm, I digress....).
So, I was able to buy the parts for the 5/8 3v model from Organ Supply for less than $25 (I think around 15 of pieces of 1/8" ash dowel at $0.32 per 4 foot length, about 15 feet of 1/8 ID plastic tubing, can't remember the price, but it was like $0.30 per foot, and about 100 2-10x3/4" machine bolts with phillips heads, nuts & washers).
I had a bit of model enamel paint & paintbrushes laying around, and a Dremel with a tube of cutoff wheels & small drill bits, and some scissors & needlenose pliers & a #1 phillips screwdriver.
And about 5 hours later I had a dome. Whee.
And then about an hour after that I had a bunch of broken struts from trying to remove the not completely cured painted strut ends from the 1/8 ID tubing. Heh.
So, then I got some talcum powder to kind of lubricate things. This had the totally cool added benefit of giving everything a playa like coating of dust.
This, and a printout of a 3v diagram from Tara kept my themecampmates busy for a good couple of hours at our last planning meeting (well, that and the scale dollies; well, actually, after 45 minutes it was mostly just the dollies; on the dome, on each other, etc.; kids, what can I say <g>). By the time we got to the Merced Burn they were well versed in dome assembly.
Oh, and another comment on the dollies. They come most easily in 6 inch (1/12 scale), so building a model to those dimensions seems to work out best if you plan to do some doorway sizing, etc.
I plan to have the model set up early Sunday morning, August 29, so the design & parts monitor on the assembly crew can quickly sort things out.
1) Scale model in the frequencies I wanted (3v, 4v, 5v).
2) Useable for stress testing (the magnetic sets move around way too much).
3) Very compact & who cares if it gets a bit bent or broken, or a few parts wander off (not like those damn Lego model kits where one teeny little missing part under the couch can bring a fun time to a grinding halt! Hmm, I digress....).
So, I was able to buy the parts for the 5/8 3v model from Organ Supply for less than $25 (I think around 15 of pieces of 1/8" ash dowel at $0.32 per 4 foot length, about 15 feet of 1/8 ID plastic tubing, can't remember the price, but it was like $0.30 per foot, and about 100 2-10x3/4" machine bolts with phillips heads, nuts & washers).
I had a bit of model enamel paint & paintbrushes laying around, and a Dremel with a tube of cutoff wheels & small drill bits, and some scissors & needlenose pliers & a #1 phillips screwdriver.
And about 5 hours later I had a dome. Whee.
And then about an hour after that I had a bunch of broken struts from trying to remove the not completely cured painted strut ends from the 1/8 ID tubing. Heh.
So, then I got some talcum powder to kind of lubricate things. This had the totally cool added benefit of giving everything a playa like coating of dust.
This, and a printout of a 3v diagram from Tara kept my themecampmates busy for a good couple of hours at our last planning meeting (well, that and the scale dollies; well, actually, after 45 minutes it was mostly just the dollies; on the dome, on each other, etc.; kids, what can I say <g>). By the time we got to the Merced Burn they were well versed in dome assembly.
Oh, and another comment on the dollies. They come most easily in 6 inch (1/12 scale), so building a model to those dimensions seems to work out best if you plan to do some doorway sizing, etc.
I plan to have the model set up early Sunday morning, August 29, so the design & parts monitor on the assembly crew can quickly sort things out.
"Yes, but is it art?" "No, Art is over there, on the couch."
I actually tried to make an exact scale model of a 2V dome, down to the nuts and bolts. Got to one complete hexagon and gave up. Switched to chopsticks and Elmer's. On the bright side, the hexagon turned out to be the inspiration for my "sits-on-the-dome" -style decks! (Struts radiate from the Noth Pole vertex out to five right-angle brackets, each with two short struts, making ten achor points. Or nine, if you leave a space for a ladder.)
Howdy From Kalamazoo
Cool! Got caught up in too much (work, helping friends move, covering design) to post much of late, but look forward to keeping up the exchange.
I hope to post a story soon about Annie Oakley (one of the model dome dollies) and her adventures with a Raytek thermometer.
(ahem, no, I did not mean THAT kind of thermometer adventure <g>)
I hope to post a story soon about Annie Oakley (one of the model dome dollies) and her adventures with a Raytek thermometer.
(ahem, no, I did not mean THAT kind of thermometer adventure <g>)
"Yes, but is it art?" "No, Art is over there, on the couch."
Here Kids, go crazy!
http://www.shelter-systems.com/modle.html
http://www.avatar.com.au/domes/paperModel.html
http://www.sassafraswilds.net/domehome/ ... lpg01.html
http://www.sassafraswilds.net/domehome/ ... lpg02.html
http://www.dstoys.com/products/DesignSc ... RC.15.plas
http://www.domesnorthwest.com/scale_model_dome_kits.htm
http://buckminster.info/Index/GeomModels.htm
http://www.gardendome.com/models/dome_models.html
http://architecture.about.com/library/ucdome.htm
http://www.seed.slb.com/en/lab/buckyball/index.htm
http://www.yesmag.bc.ca/projects/geodesic.html
http://www.freepapertoys.com/pt-geometric.html
http://www.shelter-systems.com/modle.html
http://www.avatar.com.au/domes/paperModel.html
http://www.sassafraswilds.net/domehome/ ... lpg01.html
http://www.sassafraswilds.net/domehome/ ... lpg02.html
http://www.dstoys.com/products/DesignSc ... RC.15.plas
http://www.domesnorthwest.com/scale_model_dome_kits.htm
http://buckminster.info/Index/GeomModels.htm
http://www.gardendome.com/models/dome_models.html
http://architecture.about.com/library/ucdome.htm
http://www.seed.slb.com/en/lab/buckyball/index.htm
http://www.yesmag.bc.ca/projects/geodesic.html
http://www.freepapertoys.com/pt-geometric.html
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Bob
- Posts: 6747
- Joined: Wed Sep 03, 2003 10:00 am
- Burning Since: 1986
- Camp Name: Royaneh
- Location: San Francisco
- Contact:
Amazing desert structures & stuff: http://sites.google.com/site/potatotrap/
"Let us say I suggest you may be human." -- Reverend Mother Gaius Helen Mohiam
"Let us say I suggest you may be human." -- Reverend Mother Gaius Helen Mohiam
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juanicoheal
- Posts: 167
- Joined: Tue Jan 27, 2004 4:47 pm
- Location: British Columbia
How about a door?
OK, so I'm contemplating building a 2V dome to bring to BRC 2004.
My question #1 is - what about a doorway? I can't seem to find how to make an entry point.
Question #2 - Covering the dome? What works? What doesn't?
cheers,
Ronnie
My question #1 is - what about a doorway? I can't seem to find how to make an entry point.
Question #2 - Covering the dome? What works? What doesn't?
cheers,
Ronnie
#1- You can distort the geometry of a dome to allow for a larger opening- On an earlier model I opened up one of the pentagons, pushing two struts to each side and raising the top one. I then added short struts cut to fit. HOWEVER- Any tinkering you do will affect the strength of the dome. If you want it for shelter and aren't putting a revolving restaurant on top, a little playin' around won't compromise it too much. Best to build it, change it, and then TEST IT.
#2- For cheap, easy protection against sun, wind and dust: silver tarps. Layer them like shingles, and use several smallers instead of one bigger to avoid the "parachute effect". Fasten with zipstrips, and reduce flapping by anchoring with utility cord. Adjust with spring clamps. There are a zillion combinations of coverings to use, many more artful than tarps, but just to have done with it you can't beat 'em.
#2- For cheap, easy protection against sun, wind and dust: silver tarps. Layer them like shingles, and use several smallers instead of one bigger to avoid the "parachute effect". Fasten with zipstrips, and reduce flapping by anchoring with utility cord. Adjust with spring clamps. There are a zillion combinations of coverings to use, many more artful than tarps, but just to have done with it you can't beat 'em.
Howdy From Kalamazoo
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juanicoheal
- Posts: 167
- Joined: Tue Jan 27, 2004 4:47 pm
- Location: British Columbia
Thanks Robot,
I made a model last night out of cardboard strips and paper clips. - cheap 'n' easy. I actually got it put together first shot !!! - kinda thought the pentagon was the way to go, but was worried about strength. All the talk about gale-to-hurricane force winds has me a little worried. I'm imagining calling out for Toto somewhere over Vegas.........
About the tarps - they don't bunch or lay funny?
I made a model last night out of cardboard strips and paper clips. - cheap 'n' easy. I actually got it put together first shot !!! - kinda thought the pentagon was the way to go, but was worried about strength. All the talk about gale-to-hurricane force winds has me a little worried. I'm imagining calling out for Toto somewhere over Vegas.........
About the tarps - they don't bunch or lay funny?