First attempt at a dome. Need direction.

shane · Post by **shane** » Mon Sep 22, 2003 9:56 am

Our camp wants to have a large dome next year. I was wondering if someone could point me in the right direction. Do you buy the domes or are they each individualy contsructed?

Thanks

Guest · Post by **Guest** » Mon Sep 22, 2003 10:07 am

If you choose to build your own, find someone who's good at trigonometry (if you're not) and check out these two links:

http://www.colorado-research.com/~gourlay/dome/

http://www.desertdomes.com/domecalc.html

Parachutes can be bought fairly cheaply on eBay. I'm told that lighter-colored ones tend to be cooler. Parachutes are pretty thin so it's not a bad idea to design an extra cover for the top that will block or reflect the sun (such as one of those mylar emergency blankets).

I've seen other domes with individual panels instead of a single cover, however I have no experience with those.

Final note: the winds out there can be devastating. I wouldn't use anything less rigid than 1/2" EMT.

robotland · Post by **robotland** » Mon Sep 22, 2003 10:34 am

How big is "big" for a dome? Spring for the 3/4" conduit REGARDLESS of size, unless you're going over 20' diameter in which case you might want to go 1". Depends on whether it's just going to hold up a parachute or you plan to swing lots of hammocks from it or put a deck on it.....This year we brought an 18' frequency 2 dome with a 10' dome and wooden deck that sat on top, all made of 3/4", and covered with tailored silver tarp sections. Solid as a rock. If I've learned anything about domecraft it's to NOT CHEAP OUT ON HARDWARE- if you use little dinky cheap nuts and bolts the threads will strip and make disassembly/reassembly a real bitch- Buy grade 5 n's and b's from your local farm supply, and make 'em 1/4" or 3/8". Use big washers. When you've test-assembled your masterpiece go through and colorcode with spraypaint. You won't believe how much this helps, especially if your structure is more than a frequency 2 or is otherwise complicated! I colored each level of struts diffrently, so when I go to build I can just find ten all-blue struts for the bottom circle, then find the blue-on-one-end-green-on-the-other struts that go up to the all-green level, and so on....I just got a serious pang of Homesickness yesterday and put up the big dome- even alone and with a hangover it was up in an hour! I can provide other little bits of wisdom regarding dome construction upon demand, but Tara's Desert Domes is truly da bomb- Especially the Dome Calculator. Long May She Wave!

Badger · Post by **Badger** » Mon Sep 22, 2003 10:35 am

Final note: the winds out there can be devastating. I wouldn't use anything less rigid than 1/2" EMT.

The Dome Calculator is pretty darn cool. My first few domes were using it. 1/2" electrical conduit works well but 2002 showed the weaknesses inherent in using 1/2" for a v2 style dome. From this point on I'll do either 3/4" v2 style dome (with a diameter less than 15') or 1/2" v3.

If you're thinking about a larger dome for your group (25'-30' or greater) you definitely want to consider v4 or possibly v5). Also, nothing smaller than 1" conduit piping as a rule.

Guest · Post by **Guest** » Mon Sep 22, 2003 10:51 am

Badger wrote: Also, nothing smaller than 1" conduit piping as a rule.

When I build things I'm usually in the "be here when we're gone" camp but I have to disagree with you guys on this. 1" steel conduit is freakin' HEAVY, not to mention taking up much more space. I built a 22' diameter v2 dome using 1/2" EMT. Yep, that means the long struts are about 6.5 feet. I can't climb on it and I can't build a deck on top, but it's strong enough to withstand the wind and I can get it there in the cargo box atop my car. That's a big deal when you've got 600 miles to drive.

Badger · Post by **Badger** » Mon Sep 22, 2003 11:24 am

I have to disagree with you guys on this. 1" steel conduit is freakin' HEAVY, not to mention taking up much more space.

Not steel. Aluminum. 1" conduit is something you want to use for the larger domes. I believe Thunderdome is a good example. 1" pipe and v4 configuration. I think the pipe may also have lengths of rebar inserted into them to keep from bending.

Guest · Post by **Guest** » Mon Sep 22, 2003 11:46 am

I should just let this go but I have to ask -- what is aluminum conduit?

Badger · Post by **Badger** » Mon Sep 22, 2003 3:02 pm

Aluminum electrical conduit. Get at Home Depot in various sizes. It's easier to handle, cut, press and drill than steel pipe. Considerably cheaper as well. I suspect 90% of every geodesic dome structure you see on the playa is made of this stuff.

robotland · Post by **robotland** » Tue Sep 23, 2003 5:56 am

Let's stop for a moment and clarify the whole steel-aluminum pipe thang....That thin-walled stuff that you buy in quarter-inch diameter increments, the rolled stuff with the seam, that stuff, it ain't aluminum, brother....you can buy aluminum stock over in the hardware department, and it costs A BUCK A FOOT AT LEAST. The thin-walled ELECTRICAL CONDUIT, or "thinwall", is commonly referred to as E.M.T. (electrical metal tubing) and is rolled, galvanized STEEL. (Remember about the galvanized part if you decide to play with welding it....nasty fumes!) There is also bigass heavyr'nshit thickwalled conduit, with threaded ends, that looks like iron gaspipe but is generally silver/gray. Heavy. Expensive.
If it's a half-inch in diameter, weighs a coupla pounds, is thin-walled, shiny silver OR dull gray with blue stencilled inch increments, and costs somewhere between a buck and buckandahalf, then you've gotcherself a stick of E.M.T.. 3/4" Costs two-and-change. When I wander into the Gnome Depot I carry a little "keyring" with 6" lengths of the common pipe sizes and materials that I use in structures (1/2, 3/4 and 1" EMT, 3/4 PVC, 1/2 and 3/4 ABS, and 1/2 rebar) so that I can easily compare the way that couplers and fittings work with the different materials. (I like the rebar-inside-conduit idea- I've tried conduit-in-conduit, don't bother.) Be sure to check whether the size indicated is INSIDE or OUTSIDE diameter.
They tricky!
MC if this is TMI re: EMT.

Guest · Post by **Guest** » Tue Sep 23, 2003 6:57 am

Thanks for the clarification, 'bot. I used 1/2" EMT for my dome. Steel.

And I stand by my heavy statement (though clearly not as heavy as rigit conduit). The struts for my dome (65 of 'em, 1/2" steel EMT) easily weigh over 100 pounds. I don't even want to think about the weight of using 1" conduit -- IMHO you have to really want a strong structure to go to that trouble.

robotland · Post by **robotland** » Tue Sep 23, 2003 7:25 am

I can dig it. Weight's a bitch cross-country. We dragged our big living contraption 2000 miles in a Y'All Haul...But I REALLY like tightening that last nut and having that big wiggly pile'o'conduit change into Super Beefy Shelter And Jungle Gym Supreme...I think there were about 150 parts and the whole thang weighed 200 pounds or so. Tomorrow I'm reassembling the whole damn thing and adding a 6' sphere and pentagonal cone to the top; Should be about 30' tall and roughly conical, so I can wrap it all up in one big tarp like a sushi summer roll! This will be my Michigan Winter Playa Surrogate Structure, complete with dusty groundcloth!

Guest · Post by **Guest** » Tue Sep 23, 2003 7:53 am

Sounds cool... post a picture when you finish getting it covered!

Skyhawk · Post by **Skyhawk** » Tue Sep 23, 2003 11:29 am

are Home Depot prices the only ones out there?

its about the same at any home improvment place, but are electrical contractors really paying that much per stick? anyone have a lead on a Cheaper place? heard of a manufacturer who sells in any amounts less then a "unit"? (which is a few hundred at the very least, at least thats how they come off the truck)

fantasy might become reality if I can secure myself a goodly number of pieces.. and another note. any DFW area burners listening? feel like splitting the cost of a unit or bulk order?

Blenderhead · Post by **Blenderhead** » Tue Sep 23, 2003 4:05 pm

Robotland wrote:

"This year we brought an 18' frequency 2 dome with a 10' dome and wooden deck that sat on top, all made of 3/4", and covered with tailored silver tarp sections. Solid as a rock."

Screw waiting to see what the new incarnation will look like! Do you have pics of what you describe above looked like? Sounds abso-fucking-lutely fantastic.

Badger · Post by **Badger** » Tue Sep 23, 2003 4:59 pm

Robotland,

You're right of course. It never dwaned on me that it could be iron v aluminum. I've just always assumed - incorrectly. Thanks for the clarification.

Over the years I've built um, 4 geodesics using the conduit. Because pipe genrally comes in 10' lengths, I've gone with the v2 version where I can get one of each required lenths out of a single piece. I've then taken them to work and pinched each end with a massive vise that takes the better part of an afternnon. I found out we have a small 30 ton hydraulic press that takes care of a pole end in VERY short order. I now figure that it might be possible to actually fabricate two complete domes by myself in the course of a day. Am thinking of maybe shooting for 5 domes and have them set up along a pentagram where each would serve a purpose (kitchen, bedroom, shower, lounge, storage) and then drape the whole 'complex' with several large pieces of cammo net and maybe waterproofing.

polykarmatic · Post by **polykarmatic** » Tue Sep 23, 2003 6:01 pm

I've LOVED the information and discussion about Dome construction.

I'll just throw out another idea for a low tech option. Our two little dogs really enjoy their 12' X 6' X 6 foot Dog run. It cost less than $200. bucks and all the materials were included. Assembly was a snap using a wrench. It occurs to me that It might be a satisfactory frame work for a shade structure.

It all came in a box that was about 8" square and 6 Feet long (including the chain link fencing that would stay home)
It would be relatively easy to attach tarps or shade cloth to the galvanized frame work of the dog run.. It even has a door..
I realize its only large enough for one or two people but its another option for those of us using a tent.

robotland · Post by **robotland** » Thu Sep 25, 2003 8:30 am

You could even start a theme camp around the idea of those kennels! I just wish that they made those cool plastic Dogloo igloo-shaped doghouses in people sizes.......I've even seen precut shade tarps for those kennels!

robotland · Post by **robotland** » Thu Sep 25, 2003 8:46 am

Hey Badger! I've been doodling some plans for little groupings of domes, too! We might have to collaborate on Dometown some year...I really like the idea of a circle of small domes supporting a big central shade dome.
I've been doing experiments with stacks of domes as well- yesterday I grafted a 2V 6' dia. 3/4 sphere onto a 2V 10' dome, which will all sit atop an existing 2V 18' dome. Looks cool, but hard to cover smoothly....going to try running vertical struts between the sections so one bigass tarp can just wrap around....I'm trying to find a good shot of our structure from Hushville this year, and will post. (The new structure is based on that one.)
The most important lesson that I learned from actually taking the finished, tested structure to the event was that although it worked structurally above and beyond my expectations, I failed to construct the opening and frontage in a way that invited visitation and as a result I missed out on many potential visitors! Those who did visit enjoyed the vantage point and cooling breeze from the upper deck, which made me proud, and I have already drawn up some improvements involving an external ladder, friendlier facade and walk-through misting arch.....

Kinetic · Post by **Kinetic** » Thu Oct 02, 2003 8:27 pm

The dome calculator at desert domes is nice but when your math skills suck like mine, converting all that stuff to inches and feet is a pain. My first dome was built out of 1/2 EMT and was a 3v 15 ft size. I didn't get the measurements right and when I built it I never did get it all the way finished. But even in it's partial configuration it seemed pretty strong. I wouldn't stand in the middle of a strut but at 270 lbs I could hang from the thing and it held me.

Weight and space are becoming critical for me unless I buy that school bus I've been thinking about. KC to BRC is 3600 round trip, and the route I take has 7 passes and hits 11,000 ft. Sorry I-80 across Wyoming is not an option. Anyway I like my 1/2 emt. Now if I can just figure out how long to cut the struts next time. Also I love my cheap Harbor Freight arbor press....$40 and it does a number on smashing those ends flat.

robotland · Post by **robotland** » Fri Oct 03, 2003 6:41 am

If you dig around in Tara's site you'll find the coversion formulas for decimal-to-feet...(I share your mathematical aversion!) To eliminate weight issues for transport, you could try this idea that I've been playing with: Make all struts PVC, with conduit ends....With a little trial and error I have found sizes that fit snugly without having to glue (or worse, TAPE!), and if there's not going to be any climbing or monkey business (a pity) on the structure then everything'll hold up famously! Use your favorite dome formula, and use about a foot (on each end of each strut) of rigid EMT that has been flattened in the traditional fashion and drilled. Bolt together, Serve, Enjoy! It's light, it's flexible, it's versatile! Just stake the crap out of it........

Smudge · Post by **Smudge** » Fri Oct 03, 2003 5:52 pm

I believe a hemispherical and a lesser spherical section bucky dome
could share the same ground-level outer rim, as long as the rim
itself has good circumferential tensile strength to support the
outward force from the lesser dome. That configuration might allow
the tall one to provide shade while the lesser provides shelter from
rain, or a habitable space between the top of the smaller and top of
the larger domes, though it would be "on a mound." Well, mounds are
good, no?

drive dog

Written by David

Kinetic · Post by **Kinetic** » Fri Oct 03, 2003 9:01 pm

Smudge, maybe it's just me but the font color you used was pretty hard on the eyes. With the regular BM color scheme on here, that orange is harsh!

That was your first post and I don't want to scare you off...we need more people posting around here!

robotland · Post by **robotland** » Mon Oct 06, 2003 5:27 am

Once my eyes recovered from the PissFont I dug where Smudge is going, though...I didn't think about going about nesting two domes in such an elegant way, though- just making two that are a hair different in size and maybe filling the void with something...(balloons? stuffed animals? junk mail?) Or, hold an inflatable membrane in place between 'em....Or a heavy-duty water-filled bladder with aerators, live fish and such...Playaquarium!

Skyhawk · Post by **Skyhawk** » Mon Oct 06, 2003 1:25 pm

if you were clever (and had enough time, money, equipment, supplies, etc) to work it out, I think you could use Vacume to fill the void.. ok.. that dosnt make sense.. another way to put it.. um..

well, that post righjt up there, a kind of playaquarium.. why not make a plastic "air bladder" out of some pretty strong stuff, but REmove the air to make it the final shape.. like those food-saver things that suck out all the air around your steak, then seal it off. maybe if you were clever about it, a similar device (though more robust and certainly not for food storage) could shrink down some kind of "bag" around sections of dome, increasing ridgidity.. oh.. or not that I Think about it, those large, thick plastic pallet wrappers that are already used in industry might do it, using a heatgun instead of trying to suck out air..

Im rambling.. who knows.. but next time your at your local Home Depot, try and take a peek at the way the full pallets of concrete and sand are held together.

Don Muerto · Post by **Don Muerto** » Mon Oct 06, 2003 8:33 pm

skyhawk, -interesting idea about the shrink-wrap but who would need a heatgun in BRC? You would have to cover it at night and watch it shrink down to the frame by 8:00 a.m.

Spokes · Post by **Spokes** » Mon Oct 06, 2003 8:57 pm

Just a bit more clarification on electrical conduit. Heavywall conduit is available in aluminum in all trade sizes. It costs a bit more than steel. I haven't bought any in a few years but my guess is contractor price is about $100 per hundred feet for 1/2" trade size as opposed to $14.00 per c on 1/2" emt and $55.00 or so for heavy wall galvanized steel. You won't find it at any home supplier or most electric suppliers unless there is industry in the area that requires it in their plant. It bends fairly easy as well and steel may still be an overall better choice for making structures when you take that into consideration.

Thinwall is available in aluminum in the larger sizes, 2"-4" trade size I believe but I've never seen the stuff.

PDF spec sheet on the stuff http://www.alliedtube.com/alumcond.pdf

robotland · Post by **robotland** » Tue Oct 07, 2003 5:51 am

Really! I want some. Never seen it or heard of it before!

For covering- how about that Saran Wrap stuff that comes on a spindle, used to bund palette goods?

Alpha · Post by **Alpha** » Tue Oct 07, 2003 6:49 am

robotland wrote:For covering- how about that Saran Wrap stuff that comes on a spindle, used to bund palette goods?

Covering a dome with this reminds me of the fruit dehydrators I used to make as a kid. Sounds like a good way to make Baked Burners!

Skyhawk · Post by **Skyhawk** » Tue Oct 07, 2003 8:58 am

I meant a wrap more like This

http://www.uline.com/ProductDetail.asp?model=S-7737

ah.. ULine.. fun for all ages..

Skyhawk · Post by **Skyhawk** » Tue Oct 07, 2003 9:01 am

and muerto..

you would still want to heat-gun shink it I think
do you want that super early morning wind to blow it away while its still 50 degrees outside? and with a gun you can control the shape, so it forms down instead of all curling into a blob on one side or something

First attempt at a dome. Need direction.

First attempt at a dome. Need direction.

dome-o arrigato, Playa Gelato

pipe dreams

heavy, man

Re: heavy, man

Conduit

Robot's dome!

Dog Kennel Kit 6ft high x 12ft long x 6ft wide

in the dog house

multidome fantasies