DOOOOOME! I'm making a DOME!

Right, so my garden shed is...well, kinda crap. It looks like it used to be a chicken coop, and looks like it was cobbled together about 50 years ago and randomly patched at multiple points since then.

...soooo.....new shed time. :D And as you may have guessed, I'MA MAKE A DOME! :D A geodesic 1V dome, to be exact.

Why? 'cause I like domes and domes are cool, that's why. :P
Also, according to my calculations, the materials will cost about half what the materials for a similarly sized normal shed would. AND IT'S A DOME! :D


Right, so I've never actually built a dome before, so today I made a scale(ish) model out of dowels and tubing. I got the idea from this site, where they recommended using 1/8" dowels and 1/8" ID tubing to stick them together at the corners. Now, there were a few problems with that. First, I couldn't find any 1/8" dowels at Home Depot, second, once I stopped to think about it, I decided I wanted to use much thicker dowels for the size model that I wanted to make, and third, I remembered a while ago I picked up a bunch of 3/8" ID 1/2" OD watercooling tubing from Microcenter for, like, $3 for 8'. So, since that was thin-wall tubing like I wanted, I decided to just get 3/8" dowels instead, which worked out much better size-wise.

I got the rough design from that same site, which gave me an idea of how to shape the dome and what sort of connectors I would need to make.

Now, the shed I'm going to make with 8' struts because, well, that's an easy size to make because I can just use 8' boards...and more than 8' would just be really freakin huge and completely unnecessary. I decided I wanted to make about a 10:1 scale model, but that would have required me using 9.6" struts...and the dowels came in 4' lengths, so that would have required me wasting a lot of dowel...so I used 9" struts instead, so this is actually a 10-2/3:1 scale model...oh well. :P

I forgot to take pictures of the cut dowels and hose pieces initially, so let's start with the base done!

Then I just had to turn this:

Into a bunch of these:

..well, except that I forgot I needed 5-way connectors, not 6-way....and I didn't realize that until after I had already killed my fingers making three 6-way pieces. :(

Oh well, eventually I got here:

And then here! :D

So, stay tuned. I won't be making the full-size one until I get a job, but I have an interview tomorrow, so...*crosses fingers* Anyways, in the mean time I'll be finalizing my plans for how I'll be making the full-size one. I mentioned I'll be making it out of wood, yes? Well, I looked around online and the only plans I can find for making geodesic domes out of wood all involve special, expensive adapters, fancy multi-sided joint pieces, or lots of hinges and sawdust and glue....and I thought those were all just silly, so I'm designing one that I can make entirely out of 2x4's and plywood (well, and screws) with no cuts that can't be done with a standard mitre saw. So, I'll post those as I finalize them.

Looks good. Good luck on the interview. Hopefully its a job you really like.

Thanks. It does sound like a pretty cool job, but I won't go too much into it unless I get it...and know what it really is instead of what I'm inferring from the job listing. ;)

It's kinda funny, I've been in kinda a funk the last month or so, but the giant robot dude's videos gave me a kick in the pants to start working on fun stuff again...and now instead of being depressed and apathetic about not having work, I'm just annoyed that I don't have a job to fund my projects. :P Well, hopefully I won't have to worry about that much longer...anyways, off to sleep so I can wake up early-ish tomorrow.

Good luck at the interview.:crossed:

Hexagons could drop your corners to 3 per vertex.
8' struts are going to make this shed huge no matter how many sides it has. I would calculate the square footage you think you need (and then add, say, 50% :D) since cutting off 2x4s is cheaper than buying additional plywood and other materials. You'll have a nice shed to store scrap lumber in anyway!

Sounds interesting but you realize that some people might think it's a radar dome and drop bombs on you, they are watching you know :D

Sweet! I had a feeling this was GRP inspired just from the title actually ;)
Looks good though man, sounds like it should be pretty fun to work on too. Good luck with t'interview too, I hate them buggers :( Keep us posted on your progress!

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Originally Posted by mDust

Good luck at the interview.:crossed:

Hexagons could drop your corners to 3 per vertex.
8' struts are going to make this shed huge no matter how many sides it has. I would calculate the square footage you think you need (and then add, say, 50% :D) since cutting off 2x4s is cheaper than buying additional plywood and other materials. You'll have a nice shed to store scrap lumber in anyway!

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Yeah, but hexagons are a lot harder to make and the benefits of using hexagons are much smaller with small domes, and especially small, low-resolution domes like this one. Besides, like you said, 2x4's are cheap. ;) [EDIT]Plus, even though the number of corners per vertex would drop, I think the number of vertexes and the number of struts would probably rise a lot.[/EDIT] Oh, and using 8' struts, covering each face will take one full 4x8 sheet with practically no waste. Though, I'm only doing the lower surfaces with plywood; the upper surfaces I want to do with some sort of translucent stuff..I'll have to go wander around Home Depot or something and find something good. If I were to cover all the sides with plywood though, using some nice 23/32 stuff, current cost estimate is ~$250. Bump that up to probably ~$300 if I put in a wood floor...which I probably will but might no...I haven't decided yet. That comes out ~$100 less than my estimated materials cost for a similarly sized, more traditional, design (10'x10', single-slant roof sloping from 10' in from to 8' in back).[EDIT]..nvm, checked my numbers again, and they're actually about the same cost. But domes are so cool! :D[/EDIT] For comparison, the closest thing I could find real quick on Lowes' website was this 10'x10' wooden barn-like-thing, for almost $900! :eek:

According to my calculations, 8' struts should give me about 110sqft of floor space, and with the low-resolution design I'm using, my side walls will be about 7' tall (7.05', to be precise) before the real sloping-in starts, with a peak of about 11' inside.

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Originally Posted by Beta-brain

Sounds interesting but you realize that some people might think it's a radar dome and drop bombs on you, they are watching you know :D

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Hmm, I do live near Goddard Space Center... :freakedout: :whistler:

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Originally Posted by Munty

Sweet! I had a feeling this was GRP inspired just from the title actually ;)
Looks good though man, sounds like it should be pretty fun to work on too. Good luck with t'interview too, I hate them buggers :( Keep us posted on your progress!

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Heheheh, yup! His dome got me thinking along those lines, and a bit of research made me decide a fully wooden design was best for my purposes, since I want to have hard, permanent, walls mounted directly on the frame.

Thanks for the interview well-wishes, everyone. I'll update here afterwards (it's at 2pm EDT).

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Originally Posted by mDust

Good luck at the interview.:crossed:

Hexagons could drop your corners to 3 per vertex.

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I believe you mean pentagons. If you use hexagons, you would just get a flat sheet, not a dome- each vertex has a 120 degree angle, so 3 hexagons makes a full 360 degrees, meaning no curvature.

I can't wait to see this full size! Good luck with the build.

This.... is gonna be massive.

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Originally Posted by Technochicken

I believe you mean pentagons. If you use hexagons, you would just get a flat sheet, not a dome- each vertex has a 120 degree angle, so 3 hexagons makes a full 360 degrees, meaning no curvature.

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That doesn't make any sense. I meant hexagons. A dome can be made out of any symmetrical polygon and many asymmetrical polygons.

I know what hexagons are...
In that picture they must not be using regular hexagons, which significantly complicates the structure. Also, that structure has at least a few pentagons in it as well. Regular hexagons form this structure, which is planar:

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Originally Posted by Technochicken

I know what hexagons are...
In that picture they must not be using regular hexagons, which significantly complicates the structure. Also, that structure has at least a few pentagons in it as well. Regular hexagons form this structure, which is planar...

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We are both partially right. The hexagons are normal hexagons but they do have pentagons to give the curve. It's a geodesic, the most famous example of which is a soccer ball.

Knowledge is power, let's take over the world.:up:

I don't think a geodesic would be any more complicated.

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Originally Posted by mDust

We are both partially right. The hexagons are normal hexagons but they do have pentagons to give the curve. It's a geodesic, the most famous example of which is a soccer ball.

Knowledge is power, let's take over the world.:up:

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They actually can't possibly be regular hexagons. In order to make a solid out of regular hexagons and pentagons, you must have two hexagons and 1 pentagon at each vertex. The hexdome you linked to has 3 hexagons at most vertices. If there are three hexagons meeting at a vertex and they do not lie on a plane, the angles meeting must add up to less than 360. Therefore, the angle of each one must be less than 120, meaning the hexagon is not regular. Similarly, in a geodesic dome made up entirely of triangles, the triangles are not actually equilateral- the largest shape you can build with only equilateral triangles is a icosahedron (which is essentially the shape x88x is building, but the bottom is lopped off his).

I imagine the 6 sides of each hexagon are of different lengths. The higher up the dome you go, the smaller the hex's would need to be in order to allow for the pattern to 'taper'. Of course even then it's impossible without pentagons (unless you want to make it REAL ugly!) but TC is right, if 3 hexagons all meet at one vertex then they will produce a flat surface unless there is some sort of deformation in the angles of the corners of lengths of the sides.

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Originally Posted by Technochicken

They actually can't possibly be regular hexagons. In order to make a solid out of regular hexagons and pentagons, you must have two hexagons and 1 pentagon at each vertex. The hexdome you linked to has 3 hexagons at most vertices. If there are three hexagons meeting at a vertex and they do not lie on a plane, the angles meeting must add up to less than 360. Therefore, the angle of each one must be less than 120, meaning the hexagon is not regular. Similarly, in a geodesic dome made up entirely of triangles, the triangles are not actually equilateral- the largest shape you can build with only equilateral triangles is a icosahedron (which is essentially the shape x88x is building, but the bottom is lopped off his).

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This is correct. Hex-domes do have to have the occasional pentagonal surface in order to, well, form a dome. If you watch this image (mirrored from wikipedia, from the geodesic dome article), you can see the occasional pentagonal surface.

Also, yes, more complex triangle domes do have to have non-equilateral triangles. Some common triangle dome designs are shown here:
http://www.desertdomes.com/domecalc.html

The dome design I am building is what is referred to on that site as a "1V" dome, and is the only design that is made entirely of equilateral triangles. I chose this design both because it is the simplest, requiring the fewest joints and struts, and because it has the most vertical 'sides', offering more usable vertical area in this relatively small dome than in huge ones. More complex triangle domes are stronger, but this structure isn't going to be under that much stress anyways, so that doesn't really matter to me in this case. :P

I've decided I'm also going to be altering the design a bit more to make the door easier. I was talking to my dad about it today, and throwing around some ideas I had for the door (diagonal-upward opening split, drawbridge...really not all that user-friendly doors...) and he suggested something that I think will work great. Basically, I start with a strut on the upper horizontal layer, and drop a beam straight down from each endpoint. Then, I join the bottoms of these beams and triangulate them with the joint and beam closest to them. Like so:
The red marked beams won't be there; instead, there will be beams where the black lines are.

This will allow me to have a nice big rectangular door without compromising the dome's strength too much.

Oh, and the interview went...idk, I felt like it went pretty bad as I was walking out of it, but an hour later I thought it went pretty well. Mainly, I think I just babbled a lot and didn't ask enough about the company...hopefully I conveyed enough useful information to convince them I really do know what I'm doing. :neutral: They said they're interviewing people the rest of this week and next week, and by the end of next week they'll pick someone. ...sooo...here's hoping. :crossed: The company seems pretty cool and they make some pretty interesting stuff...I think I could be happy there for a while. They even had a (male) employee with hair almost as long as mine! :P

Hope you get the job, man! :up::)

Think I'll stick to my simple pole barn design I'm working on. I got three tractors, and a pick up that needs shade though... :D

Well, I realized that I never actually said what happened with that interview.. I bombed it, basically...but I did finally get a job. Starting next week. So, in a month or two I should be able to actually do this thing! :D

Here's the preliminary plans I drew up back in June...and that sat in my scanner and were forgotten until I needed to use my scanner again recently... :P

I'm going to go back over them this week, make sure my numbers are right, and get them finalized. I won't get my first paycheck until September 26th, unfortunately, and probably won't be comfortable dropping the $250 or so that this'll cost until October or November, but it will happen at some point.

we've got a huuuugge geodesic dome here in okc.