Geo Dome Advice

HeironymousJosch · Post by **HeironymousJosch** » Sat Nov 14, 2009 10:25 pm

This is my first post since being on playa. This past burn was my first and it's hard to put in words, so I won't! I was blessed to be a member of the BooBy bar and can't imagine there's any better burners to learn the ropes from than TITWI and Pinemom. One of the less abstract things I took away from my first year was an infatuation for Geodesic Domes. I came out a week early and had the pleasure of helping to build two domes for the BooBy bar and another for a friend's camp. I intend to build one of my own for 2010 and I need a bit of advice.

I have spent a lot of time drafting a model in sketchup. I've adapted my models from various geo dome spherical templates in the google catalog. It seems that the most appropriate type for a playa-bound dome is a Class I Icosahedron. I could be wrong about that but it appears to have more uniform strut lengths and a ring at the mid-point that is fairly close to parallel with the ground, which leads me to my question:

When the bottom half is removed from a Class I Icosahedron, there is a slight "ripple" in the lower base. There is a low point, a strut that touches the ground, on every "tenth" of the perimeter. On all the adjacent "tenths" of the perimeter, there is a high point - a strut that is several inches off the ground. On a 15' radius dome, this high point amounts to about 8" off the ground. For domes that are purpose built as free-standing structures and being flat on the ground, is this 8" negligible? Will the structure essentially settle the difference, forcing the low struts up 4" and the high ones down 4"? I can certainly adjust the length of the struts in the lower row to make the entire perimeter of the dome rest on the ground but that is going to greatly increase the complexity of the whole project.

I've found internet calculators that offer basic strut lengths based on the radius and frequency of the dome you intend to build but that's not what I'm looking for here. I'd like to draft the beast before I build it and for that I need hard geometry and some playa experience.

Dome builders! Feed me your wisdom, please!

oneeyeddick · Post by **oneeyeddick** » Sun Nov 15, 2009 8:30 am

does this mean you ain't gonna camp with us next year ?

pinemom · Post by **pinemom** » Sun Nov 15, 2009 8:53 am

HIya Hiero!

How's Jungo?

You will want to Pm STARGEEZER!!!!

He's the man who did all the calculations for Titwi's Structual cuts!

He's amazing!

xoxox
PM

oneeyeddick · Post by **oneeyeddick** » Sun Nov 15, 2009 9:17 am

Here is some good dome advice.

http://eplaya.burningman.org/viewtopic. ... t=geo+dome

Risky · Post by **Risky** » Sun Nov 15, 2009 9:29 am

We must have broke them in just right.
Virgins are so fun!
Spread your wings and fly.

gyre · Post by **gyre** » Sun Nov 15, 2009 9:57 am

Check out Domebook I and II.

http://www.shelter-systems.com/designs.html

stack · Post by **stack** » Sun Nov 15, 2009 11:54 am

how'd the hexayurt work out? we were pretty happy w/ ours, not as roomy head height wise, but way less dusty....I understand the need for projects btw :)

theCryptofishist · Post by **theCryptofishist** » Sun Nov 15, 2009 7:15 pm

Don't do this:

...'cause it's already been done.

HeironymousJosch · Post by **HeironymousJosch** » Sun Nov 15, 2009 8:58 pm

oneeyeddick wrote:does this mean you ain't gonna camp with us next year ?

I told TITWI the last time we talked that the only way in the world I wouldn't camp with you guys next year was if I started my own camp. BluCheetah, me and a few other local burner friends have discussed the prospect of starting a camp. I've also got a lot of friends that have never been interested in going. I like the idea of setting up a stable, functional camp so that they don't have to worry much their first year. Luckily, I know how to set one of those camps up because of you guys!

It will all come down to money, like it normally does. I'm budgeting a camp - shared shade structure, galley, shower, etc. and seeing where the total comes out. If that price can be shared reasonably as a camp fee between members then we're gonna go for it.

If not, I'm camping with the best damn bar on the playa, in the best damn city with the best damn group of people.

HeironymousJosch · Post by **HeironymousJosch** » Sun Nov 15, 2009 9:02 pm

pinemom wrote:HIya Hiero!

How's Jungo?

You will want to Pm STARGEEZER!!!!

He's the man who did all the calculations for Titwi's Structual cuts!

He's amazing!

xoxox
PM

Him Pinemom!!!!!!!! Sorry I haven't checked in with you guys any sooner. I've been busy as hell and to be perfectly honest, I spent most of the first two months back trying (operative word) not to focus to much on Burning Man in hopes that it might ease my decompression. Hard to say if it worked but I miss you guys like hell. I feel like maybe I'm only just now decompressing. I'll probably be glued to these boards like before!

Thanks for the tip, I think I may have sorted the thing out, for the most part. I do have one question I think I'll send his way.

I miss you!

xoxoxo

HeironymousJosch · Post by **HeironymousJosch** » Sun Nov 15, 2009 9:05 pm

oneeyeddick wrote:Here is some good dome advice.

http://eplaya.burningman.org/viewtopic. ... t=geo+dome

Excellent.

HeironymousJosch · Post by **HeironymousJosch** » Sun Nov 15, 2009 9:07 pm

Risky wrote:We must have broke them in just right.
Virgins are so fun!
Spread your wings and fly.

Yes, yes you did! Now, if I do start my own camp, hopefully I can recruit a fluffer at least half as good as you!

HeironymousJosch · Post by **HeironymousJosch** » Sun Nov 15, 2009 9:09 pm

gyre wrote:Check out Domebook I and II.

http://www.shelter-systems.com/designs.html

Thanks!

gyre · Post by **gyre** » Sun Nov 15, 2009 9:17 pm

There is part of a book online, or article, by one of the people involved in the original dome projects.
It has some real world talk about issues in dome sealing.
Fuller himself told me that building a dome from scratch is nuts unless you can justify it for a special purpose.
Wind or art would qualify, but as long as you know.
Sealing is the big issue, even with solid domes.
Ferro-cement seemed to be the most promising.
Schnee-morehead makes the best sealants I know of.

A half cylinder or modified half cylinder is easier to build by far. (Similar to quonset huts.)
I've seen versions with a modified more vertical wall.

HeironymousJosch · Post by **HeironymousJosch** » Sun Nov 15, 2009 9:21 pm

stack wrote:how'd the hexayurt work out? we were pretty happy w/ ours, not as roomy head height wise, but way less dusty....I understand the need for projects btw

The yurt was amazing! Our clearance was great due to the peaked roof we put on the door wall. We faced that wall (by dumb luck) opposite the prevailing winds, so the wind broke over the back and to either side of the peak. The rope we used for guys was shit. The door hinge needs to be re-engineered. I'm never going to use bi-fi tape ever again either. I liked the idea of using Velcro and plastic flashing like on the playatech demo yurt. I'm probably going to heist their anchoring method as well, instead of doing guy lines again. Also, One of my campmates stumbled on a brilliant idea - A tarp floor pre-cut to the proper dimensions with a heavy duty zipper sown to its perimeter. The opposite side of the zipper would be on the bottom perimeter of the walls. Not only would it be super dust free but it would automatically pull the walls into perfect alignment while setting up, furthermore you wouldn't need to bother staking a tarp down first!

And, I'm going to wuss out and wire in an A/C unit.

We had to engineer some vents on opposite walls while on the playa, the damn thing got super stuffy.

When all is said and done, I will have this thing playa bomb proof, I hope.

HeironymousJosch · Post by **HeironymousJosch** » Sun Nov 15, 2009 9:23 pm

theCryptofishist wrote:Don't do this:

...'cause it's already been done.

robotland · Post by **robotland** » Wed Nov 18, 2009 5:47 pm

To actually ANSWER your question: I've found that less than 1/2 of a frequency 2 dome takes inadequate advantage of the superb stability offered by just sitting it on its equator. And uneven surfaces digging into the playa are harder to adjust as well as forcing the joint hardware into the ground where it gets corroded and generally gunked up. More messing around during teardown=bad.

The Eden Project PASSE'?!?!?!?! I think NOT!

bobfj40 · Post by **bobfj40** » Fri Nov 20, 2009 3:52 pm

You are thinking to hard about it. Just go to www.desertdomes.com and build one. I have built many domes and my brother did all kinds of engineering on the calculations from desert domes just to know how to do it manually and it works. The first dome we made sure everything was cut and drill to 1/32 tolerance. No need at all. Just get everything within 1/2 an inch and you will be good. Drill the bolt hole 1/8 bigger than your bolt.

Spend more time on the jigs to cut, smash, and drill your struts. That is where the attention to detail will pay off.

HeironymousJosch · Post by **HeironymousJosch** » Fri Nov 20, 2009 6:52 pm

bobfj40 wrote:You are thinking to hard about it. Just go to www.desertdomes.com and build one. I have built many domes and my brother did all kinds of engineering on the calculations from desert domes just to know how to do it manually and it works. The first dome we made sure everything was cut and drill to 1/32 tolerance. No need at all. Just get everything within 1/2 an inch and you will be good. Drill the bolt hole 1/8 bigger than your bolt.

Spend more time on the jigs to cut, smash, and drill your struts. That is where the attention to detail will pay off.

Man, this is good info. I had a feeling there was more tolerance than 1/32 per strut. My design has changed to a 6v dome, which has a nice straight equator bisecting the dome. Below is a color diagram of the layout I mapped in sketchup.

One little surprise, this 32' 6V dome will be constructed of bamboo.

Crazy

bobfj40 · Post by **bobfj40** » Fri Nov 20, 2009 7:20 pm

Bamboo rocks. That is going to be so cool. What are you going to use to connect the ends?

I built a 40' 4V dome and unless you have a reason for doing the 6V it might be better to go with the 4V. fewer lengths, poles, and joints but yes the 6V is cooler. A 3V might even work

Bob

bobfj40 · Post by **bobfj40** » Fri Nov 20, 2009 7:24 pm

http://www.bamboocraft.net/forums/showthread.php?t=3694
http://www.bamboocraft.net/forums/showthread.php?t=91
http://www.stardome.jp/index-en.html
http://www.stardome.jp/how-en.html

Just some info i found on bamboo domes but I am sure you have the info allready.

Bob

HeironymousJosch · Post by **HeironymousJosch** » Sat Nov 21, 2009 3:09 pm

bobfj40 wrote:http://www.bamboocraft.net/forums/showthread.php?t=3694
http://www.bamboocraft.net/forums/showthread.php?t=91
http://www.stardome.jp/index-en.html
http://www.stardome.jp/how-en.html

Just some info i found on bamboo domes but I am sure you have the info allready.

Bob

These stardomes are absolutely beautiful. I'm going to build the dome as a 6v Class I Icosahedron, though. I'm working out the design for either brackets, flanges or both to secure the struts at each vertex. I'm trying to keep it as organic as possible, so if I end up using metal hardware, I intend to conceal it somehow. I'm drafting up a couple of prototypes, once I have them modeled, I'll see if they actually work! I'm going to stick with 6v for the aesthetics and a super strong dome; I'm hoping with only 30 - 40" struts, the thing will be scalable and the whole structure should be really light.

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