DOOOOOME! I'm making a DOME!

[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:

[mDust]

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...

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.

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

[Technochicken]

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.

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).

[Munty]

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.

[x88x]

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).

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.

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. 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. 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!

[altec]

Hope you get the job, man!

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...

[x88x]

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!

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...

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.

[Twigsoffury]

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