Geodesic domes are an efficient way to make buildings. They are inexpensive, strong, easy to assemble, and easy to tear down. After domes are built, they can even be picked up and moved somewhere else. Domes make good temporary emergency shelters as well as long-term buildings.

Perhaps some day they will be used in outer space, on other planets, or under the ocean. Knowing how they are assembled is not only practical, but also fun. If geodesic domes were made like automobiles and airplanes are made, on assembly lines in large numbers, almost everyone in the world today could afford to have a home.

The first modern geodesic dome was designed by a German engineer, Dr. Walther Bauersfeld, infor use as a projection planetarium. In the United States, inventor Buckminster Fuller obtained his first patent for a geodesic dome patent number 2, in Guest writer Trevor Blake, author of the book "Buckminster Fuller Bibliography" and archivist for the largest private collection of works by and about R.

Buckminster Fuller, has assembled visuals and instructions to complete a low-cost, easy-to-assemble model of one type of geodesic dome. Visit Trevor's website at synchronofile. Before we begin, it's helpful to understand some concepts behind the construction of the dome. Geodesic domes are not necessarily built like the great domes in architectural history. Geodesic domes are usually hemispheres parts of spheres, like half a ball made up of triangles.

The triangles have three parts:. All triangles have two faces one viewed from inside the dome and one viewed from outside the domethree edges, and three vertex. In the definition of an anglethe vertex is the corner where two rays meet. There can be many different lengths in edges and angles of vertex in a triangle. All flat triangles have vertex that add up to degrees. Triangles drawn on spheres or other shapes do not have vertex that add up to degrees, but all the triangles in this model are flat.

If you've been out of school for too long, you might want to brush up on the types of triangles.For timber domes, you can follow the classic method of cutting the angle at the tip of the strut and join them using a hub many smaller domes will use a piece of pipe to attach struts togetheror making individual triangles.

To build a geodesic dome home with standalone triangles is by far the strongest way to go, and easier to assemble each piece. But it will require cuts on 2 planes.

By this we mean to cut in 2 directions. A miter saw can be set to do this, although a radial arm saw is more precise and stable. Often the deciding factor will be how much of an angle a saw can cut. This is a critical factor to consider. You can also use a worm saw.

Radial arm saws can have that precision. Miter and worm saws, not always. And if your dome is made from individual triangles, you will need to make another type of cut along the length of each strut called a bevel. In short: 2 cuts for each strut end, bevel cut along the length of the strut if you build from triangles. Any of the above can cut dome struts for your project. Ideally a radial arm saw is preferred because it can make very precise cuts, even compound cuts for each strut.

A miter saw with the stops removed will also do a good job. For the more advanced carpenters a worm saw will work as well. Whichever you use, precision is key with timber struts. At the bottom of the page you can view a video of how to cut a geodesic strut with a compound angle.

You can also visit this website for a very detailed presentation on making timber struts. What is Sacred Geometry? Cutting timber struts For timber domes, you can follow the classic method of cutting the angle at the tip of the strut and join them using a hub many smaller domes will use a piece of pipe to attach struts togetheror making individual triangles.

How strut cuts are made Two cuts are made at the tip of each strut. You divide degrees by the number of struts X 2 2 angles on each strut. The side view shows another angle to cut. This one is the same as what you get when using a geodesic calculator Making a geodesic dome from individual triangles requires a cut or bevel along the length of each strut side to fit with adjoining ones.

Struts are all joined together without a hub system. This design uses dual layer struts. This design requires only one cut at each strut end no compound cut. Two cuts are made at the tip of each strut. This one is the same as what you get when using a geodesic calculator. Making a geodesic dome from individual triangles requires a cut or bevel along the length of each strut side to fit with adjoining ones.Click on images below to view other 3V geodesic dome calculators.

For a more detailed explanation, click here.

NOTE: If you enter a measure in feet, your results are in feet or, in the case of floor area, square feet. Same goes for meters. When entering in feet, decimals are fractions of a foot or square foot for example: 2.

The formula is: tip to hole center X 2 X number of struts. For timber domes, angles should be to the nearest tenth of a degree. Many types of connectors are available for steel and timber geodesic dome.

For more information, click here. The tables show sample costs. Material prices vary with suppliers and area. Marine Shrink Wrap 7 mil. But for a more solid, safe and permanent solution, concrete is poured into round forms to create piers. Many also use them as a base and frame for a riser wall. These piers can be of varying lengths, but as a rule for large permanent structures they should go past the frost line and preferably down to the bedrock.

As for the number of piers, this depends on your engineer, though large geodesic domes will probably require a pier at each ground vertex or hub. The following calculates the required concrete for a single pier. Keep in mind rebar should be included to strengthen any pier. What is Sacred Geometry? Build your own geodesic dome Click on images below to view other 3V geodesic dome calculators. For conduit, you can round bend angles to the nearest degree.

This is also a reverse geodesic dome calculator.On low-wing aircraft, the center of gravity is above the wing and roll stability is less pronounced. This factor requires the use of greater dihedral angles in low-wing airplanes. On high-wing aircraft, the center of gravity is below the wing, so less dihedral is required. On low-wing aircraft with wing dihedralwhen a wing rolls downward, the relative wind on the descending wing becomes a component of the forward motion of the airplane and the downward motion of the wing.

This produces a higher angle of attack on the descending wing and consequently more lift. Highly maneuverable fighter planes have no dihedral and some fighter aircraft have the wing tips lower than the roots, giving the aircraft a high roll rate. A negative dihedral angle is called anhedral. Wing Dihedral is the upward angle of an aircraft's wing, from the wing root to the wing tip. The amount of dihedral determines the amount of inherent stability along the roll axis.

Although an increase of dihedral will increase inherent stabilityit will also decrease lift, increase drag, and decreased the axial roll rate.

## 3V Geodesic Dome Calculators

As roll stability is increased, an aircraft will naturally return to its original position if it is subject to a brief or slight roll displacement. Most large airliner wings are designed with dihedral.By far the best way to see what a geodesic dome looks like is to build three dimensional models.

This is not difficult and lets you see how the geometry works, what size and shape you like and possible window and door placements.

The best drawings and photos are inferior to the simplest model when it comes to demonstrating three dimensional relationships. Playing with models can lead to the discovery of valuable insights; not to mention that they are fun to make and look beautiful too.

Before starting your first model, there are a few more simple geometric elements to become familiar with. These are:. For each type of dome there is a method of calculating strut lengths and the angles at which they meet and how they are assembled.

**Torsional angle (dihedral angle)**

Once you have a table of chord factors you can calculate strut length for any size dome you want. They are the angles that the strut ends make with the centre of the sphere. They are useful if you plan to bevel the skin panels or use bevelled struts. The diagram above shows the statistics for a Three Frequency Icosahedron Dome. Choose your method of model assembly following pages and assemble as in the diagram on page 8.

This model will sit? It is simpler to join all the pentagon and hexagon spokes together? This model will not sit flat however but will rest on the five half-hex hubs under the pentagons.

What is Sacred Geometry? There are two basic types of model building, as is full scale dome building. Building a framework and then covering it with a skin. Where the skin is attached to the struts in premade triangular panels and the panels are later bolted together. Three-frequency icosahedron spheroid Be Sociable, Share!If you want to build your own climbing wall, get this book.

Gives info about measuring and cutting dihedral angles, compound angles, and irregular shapes, and more. It's a small investment compared to the cost of a climbing wall, and hopefully will save you a lot of time and money in your project.

How to determine the compound angle formed by the intersection of two intersecting planes. Online compound angle calculator. A dihedral in geometric terms is the line formed where two planes or climbing wall panels intersect.

This is a common situation when building climbing walls. Often, two panels will intersect at arbitrary angles.

### Dihedral angle

Often it is possible to take this measurement directly. However this is not always possible. This is an online calculator for determining the compound angle, or the dihedral angle where two panels meet.

From this, the joint angles for the plywood edge and framing members can be determined. This bears explanation because the term as used on this page is the geometric dihedral, yet the audience are climbers. So let me explain the difference In the sport of climbing, a dihedral is a rock formation that is nearly vertical and forming a fairly sharp angle at the "dihedral" end. The meaning of dihedral when used as a geometric term is the line or vector that is formed along the intersection of two planes.

In the context of building an indoor climbing wall, it is the line where the two climbing surfaces intersect. The intersection is the dihedral. The angle between the two panels is the dihedral angle. Determine the dihedral angle so you know the miter angle setting for the saw blade. The calculator will give you the dihedral and joint angle for situations where you cannot measure it directly.

When your walls are inclined, the dihedral angle is not the same angle as the angle on the horizontal plane. Adjusting your joint by this calculation will give you an exact and solid joint. Be sure to verify all angles using scrap wood before making your cuts. When building a climbing wall, it is useful to have the angle which the two climbing faces meet. The builder may not be able to take a direct measurement prior to building, and as a result may need to know this angle during the design phase.Working out the angles for a 3v geodesic dome Posted on:.

The slots should be easy to cut on a table saw with a tiltable table and adjustable cut height. I doubt anyone can cut the angles to 2 decimal places but the closer the better. Ideally everything should be within a mm or so. Making the faces of the hubs the same width as the timber used for the struts would probably be best the best bet but entails different sizes for both pent and hexagon hubs.

All in all, it could be a daunting project for an experienced chippy, a novice dome builder using basic tools might need some luck from the geodesic gods. It could still be a fun project Hi Paul, Thanks for the posting.

These B struts are used to link the pentagons together and also form part of the hexagon perimeters. How did you workout the dihedral angle Colin? I managed to work out the end angles by using a formula I found on the net, I can't find it now but it's fairly simple to work out the angles if you know how long each side is on a triangle. I used the dome calculator to workout the radius and strut length.

The radius equals two of the sides and the strut length makes the bottom of the triangle. I'll post a diagram to make it a bit clearer later. I am trying to do it without hubs. Just timber!

Then, there is a tricky problem with A struts coming into B struts. And then, the problem goes to fit them perfectly when forming the pentagone in the dome. Don't want to go on the lumber before being certain! Any suggestions? Sorry for copying same on both subjects :P. Are they those painted on the drawing??? Nice one! Hey everyone,I am building an experimental speaker enclosure in the shape of a geodosic dome. I am not starting with triangles but instead using flat panel hexagons and pentagons cut out of plywood.

My problem is determining the angles the edges of the plywood should be cut to. I have been experimenting on the table saw with some trial panels and although I am close I am not getting a good fit.

The angles I have been using are in the degree range for each edge, not 12 degrees. I do see now from the above illistrations that the angles should be different for the hex and pent shapes. Please, any suggestions, thanks. All Rights Reserved.

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