Star Dome Question

[todos]

So I've been looking to build a dome, but I don't want to do a geodome, since they take an enormous amount of material to make, and a lot of time to fabricate in advance, and then a lot of time to construct on playa.

One design I've seen around the internet but only on smaller scales is a 'star' or bow dome. These look to have originally been designed with bamboo in mind but I've seen some examples of them being built with pvc:

http://www.alt-eng.com/DomePage/DomePor ... index.html

I like the design of the first dome they show for it's simplicity. However they've used 3/4" pvc and say that its maximum is 6.5m (21ft) in diameter and anything beyond gets to be pretty flimsy.

Does anyone have any experience with these? Has anyone tried making something bigger than 21 ft? Like maybe 26 ft? I have a 26ft cargo parachute that I would be using as a shade cover. What about with larger PVC? Maybe 1 1/2" or 2" ? Would these be flexible enough to bend into an arc? Or would they be too stiff/brittle?

Thanks in advance!

[FIGJAM]

The playa will shred a parachute to tatters!

[todos]

It's a cargo parachute. It has gaps that allow airflow (for wind to pass through it), and it's pretty strongly re-inforced elsewhere.

[FIGJAM]

OK, but there were pics in this thread that showed it wasn't the best idea.

viewtopic.php?f=69&t=33484&hilit=playa+wind

[MrBeardy]

[quote="FIGJAM"]The playa will shred a parachute to tatters![/quote]

If you make sure the parachute is snug around your dome, it will be fine, as mine has been for several years. Don't listen to the haters

[MrBeardy]

Also it must be noted that the area where the connectors are MUST be wrapped with some sort of cloth or other smooth material as this is what would tear your parachute or cover and rip it to shreds. As long as this is in place and there is no slack in the cover you should be fine. I would also check the cover daily as over time you will have to remove small pockets of slack so that it remains snug over the dome.

[GreyCoyote]

OP: Welcome to ePlaya!

On the subject of star-domes: These are universally weak structures. That isn't to say you can't make one work on the playa (because you CAN!), it just means you seriously need to have your act together. They are the weakest of the domes, bested even by a wig-wam! So choose your materials carefully. PVC should be somewhere at the bottom of the list. YMMV.

On the subject of parachutes, there are a LOT of reasons not to use a parachute. The biggest one is the fact it is not actually cut into a hemisphere. It's cut instead as a mushroom-shape that doesn't fit the dome. Remember what it's supposed to do: slow-down something falling out of the sky. This means a flat-ish shape and lots of drag. Neither are compatible with a hemispherical dome. Just sayin'.

The next issue is the fabric of the chute: heed well the words above about making sure there are no sharp edges. It takes very little to wear or tear a hole in a 'chute. By contrast, a canvas cover really doesn't care much about wrapped vertexes (canvas is tough stuff).

Understand that parachutes are designed with a deployed service life measured in low-double-digit minutes. They catch the air, they descend to the ground, and they are quickly gathered-up and repackaged. Lather, rinse, repeat a few dozen times, then they get cycled out. This should tell you something. Specifically, that they are not meant for continous exposure, or constant fluffing, or any abrasion whatsoever. For these reasons alone they are a poor choice for a dome cover.

As to defining those of us who are saying "don't do it!" being labeled as "haters", well... all I can tell you is this: the weather on the playa has been quiet the last few years. This should be a statistical warning sign to you. This is NOT normal. If you believe that a star dome (which is structurally the weakest of all the domes), made from PVC (which is the weakest material that will actually stand-up on it's own, briefly, on the playa), that is supporting the worst possible cover (a parachute, which is specifically designed to catch the wind) to be a good choice, then bring it and rely COMPLETELY upon it. The playa has ways of eradicating bad religious beliefs.

Do as you wish, and indeed you may get away with it. Hey, it's Burning Man! But if the playa winds come howling at 70 mph, I want to make double-damned-sure you are camped far, far away from the rest of us. Your science experiment will be halfway to Fernley and it may have killed a few of your fellow campers in the process. The fact that you are asking these questions here is *good*, but is also says you have absolutely no concept as to the forces involved and your domes inability to carry them without failure. This is bad. This is where you need to say "ah HA! This is substandard and dangerous. This is where I shall fall-back and do something better". If you do, then this thread will be worth it. If not, well... (snicker), I'll be drunk as a lord, safe in my F4 dome composed of 1-inch galvanized tubing sporting a canvas cover playing paddy-cake with Jessica Rabbit and her (not-so-evil) twin. I shall hoist a bra-strap in your general direction and invite you to join us... once you gather the moop-that-was-your-dome from the trash fence. And, you bring the beer.

[Sunbeam56]

I'm not evil, im just drawn that way...

[melodiousdirge]

OP: Welcome to ePlaya!

On the subject of star-domes: These are universally weak structures. That isn't to say you can't make one work on the playa (because you CAN!), it just means you seriously need to have your act together. They are the weakest of the domes, bested even by a wig-wam! So choose your materials carefully. PVC should be somewhere at the bottom of the list. YMMV.

On the subject of parachutes, there are a LOT of reasons not to use a parachute. The biggest one is the fact it is not actually cut into a hemisphere. It's cut instead as a mushroom-shape that doesn't fit the dome. Remember what it's supposed to do: slow-down something falling out of the sky. This means a flat-ish shape and lots of drag. Neither are compatible with a hemispherical dome. Just sayin'.

The next issue is the fabric of the chute: heed well the words above about making sure there are no sharp edges. It takes very little to wear or tear a hole in a 'chute. By contrast, a canvas cover really doesn't care much about wrapped vertexes (canvas is tough stuff).

Understand that parachutes are designed with a deployed service life measured in low-double-digit minutes. They catch the air, they descend to the ground, and they are quickly gathered-up and repackaged. Lather, rinse, repeat a few dozen times, then they get cycled out. This should tell you something. Specifically, that they are not meant for continous exposure, or constant fluffing, or any abrasion whatsoever. For these reasons alone they are a poor choice for a dome cover.

As to defining those of us who are saying "don't do it!" being labeled as "haters", well... all I can tell you is this: the weather on the playa has been quiet the last few years. This should be a statistical warning sign to you. This is NOT normal. If you believe that a star dome (which is structurally the weakest of all the domes), made from PVC (which is the weakest material that will actually stand-up on it's own, briefly, on the playa), that is supporting the worst possible cover (a parachute, which is specifically designed to catch the wind) to be a good choice, then bring it and rely COMPLETELY upon it. The playa has ways of eradicating bad religious beliefs.

Do as you wish, and indeed you may get away with it. Hey, it's Burning Man! But if the playa winds come howling at 70 mph, I want to make double-damned-sure you are camped far, far away from the rest of us. Your science experiment will be halfway to Fernley and it may have killed a few of your fellow campers in the process. The fact that you are asking these questions here is *good*, but is also says you have absolutely no concept as to the forces involved and your domes inability to carry them without failure. This is bad. This is where you need to say "ah HA! This is substandard and dangerous. This is where I shall fall-back and do something better". If you do, then this thread will be worth it. If not, well... (snicker), I'll be drunk as a lord, safe in my F4 dome composed of 1-inch galvanized tubing sporting a canvas cover playing paddy-cake with Jessica Rabbit and her (not-so-evil) twin. I shall hoist a bra-strap in your general direction and invite you to join us... once you gather the moop-that-was-your-dome from the trash fence. And, you bring the beer.

x2

As stated they can work, but they are noisy, annoying, flappy, rippy teary things. Another thing to note is that many of them are quite transparent and don't offer much in the way of sun protection anyway.