Geodesic Building with the famous danish building Blocks

This is an icosahedron dome designed to be made with drinking straws or other hollow tubes (pipe, straw, bamboo etc.).

This is a minor derivative of thingiverse.com/thing:26860
A quick and dirty hack to use pins for hollow connectors like straws/pipes/bamboo
See the thingiverse page for instructions and
desertdomes.com/pictures/dome/2vdiagram.gif
for assembly.

Look out! If you print too many connectors you may find yourself under attack from alien pentacles and hexapods (see pics of the invasion i had to fight off). Hint: the one with the extended proboscis is the leader!

This is a geodesic dome connector for a pipe or pole. It's a new type of connector where it pivots around a ring between a minimum and maximum angle. This restricts the movement of the pole to the exact angles that are used in all the different types of geodesic domes, from a 1v to 8v design.

These are parameterized connectors for building small domes for learning. They are based on effalo's V2 dome kit.

I have re-written the scad files so that now it is possible to make small connectors that work with wooden sticks of very small diameter (3mm or less).

I have tested it building 2 domes that I've called as Mini-dome and Micro-dome, with diameters of 50cm and 15cm respectivelly. I have used wooden sticks with section of 3 and 2 mm, that are very cheap and very easy to find.

The connectors are parameterized. The user has to introduce the stick diameter (in mm) and the holedepth. The size of the connector (radius and height) will be automatically calculated.

(More information in Spanish)
La versión en Español la puedes ver aquí:
iearobotics.com/wiki/index.php?title=Objeto_3D:_Mini_domo

These connectors are for standard 1/2" PVC Schedule 40 Pipe (.625 OD). The motivation for me was to have a "greenhouse" structure. So I designed them to distribute water.

A sphere thing took from the google warehouse while I was looking for an openwork style sphere.

It's one of the amazing pieces of TaffGoch : bit.ly/uku6QH

Approx. 50x50x50mm

This magnet toy is great for exploring geometric shapes and the awesome power of MAGNETS. It is inspired by natural geometry and buckyballs, which are way too much fun. Unless you eat them. DO NOT EAT THE MAGNETS.

After losing some hair over the issue, and with some help from Marius Kintel, I was finally enlightened as to why my dodecahedron was not coming out properly.

This thing represents some forms of the dodecahedron. In particular, it is combinations of the dual forms (dodecahedron/icosahedron). The .stl files are printed with a radius of 20mm, but you can change that to whatever you want either in the OpenScad, or by scaling.

The 'difference' form is probably the most interesting. It makes for a fairly decent calibration piece. It has some nicely sloping overhangs, bridges, and flat spots. I makes for some good tuning between ABS and PLA as well.

The challenge with the dodecahedron had to do with OpenScad not being happy with the pentagons I was trying to print. They had to be broken down into triangles, which Marius conveniently did for me.

In order to bake an apple pie...

I really am doing geodesic domes, but there's a long road I have to walk in order to get there.

This thing is the next incarnation of the geodesic library.

Being able to calculate strut lengths is one thing, and definitely a required step along the way to constructing geodesic domes. In fact, if you're just constructing them in the real world, the previous version of this library is enough, because you can calculate strut lengths and be on your merry way. But, if you what you're after is the ability to actually model the things and print them out, then you need a little bit more capabilities.

I found that I not only needed the list of vertices for a particular platonic solid, but I also needed edge lists. That is, a list of vertices that form edges. So, that's what's in this library. Otherwise, no dramatic changes.

I did add a polygon wireframe rendering module which takes the edge lists and renders a nice wireframe of the polyhedron in question. You can specify the radius of the 'wires'. I was toying with being able to render as flat faces as well, but that requires a lot more work than the simple approach I started out with (I am using my table saw to help me figure it out).

Since it's .scad files, you can alter them to suit your needs.

Based on several suggestions, I will likely stop using Thingiverse as my 'source repository', and put sources up on GitHub so they're more easily maintained. Then I can just drop model turds here when there's something interesting generated from the core libraries.

Wearable version of Geodesic Temple symbol.

A funny thing happened on the way to developing geodesic stuff. I found that I needed to fully develop some Platonic solids. And since I needed to develop 3 of them, I figured I'd develop them all.

This thing represents the latest incarnation of the maths_geodesic library, plus extras.

First of all, the original maths_geodesic.scad library had a small bug in the 'clean' function which prevented it from properly converting spherical coordinates.

There are a few additions:
DEGREES() - Already exists in other libraries, convert from radians to degrees
RADIANS() - Already exists in other libraries, converst from degrees to radians

deg(deg,min,sec) - Creates a data structure that holds degrees, minutes, seconds
deg_to_dec(d) - converts from that degrees data structure to decimal form

These will come in handy some time when more spherical and geographic things start to show up.

sphu_from_cart(c, rad=1) - Does the same thing as sph_from_cart, but allows you to specify the radius. This is quite handy when you're converting from some cartesian coordinates, and you want to make something with a fixed radius.

then there's some things related to polygon math. Figuring out internal angles, and the like. Perhaps the most interesting is figuring out the dihedral angle for a platonic. That comes in handy for some calculations.

But, the really new stuff is the set of thing related directly to Platonic solids in the file 'platonic.scad'.

First of all, the 5 platonic solids are represented by functions that represent their geometry/topology, in a form suitable for rendering with the polyhedron() module.

So:
tetrahedron(rad=1)
octahedron(rad=1)
hexahedron(rad=1)
dodecahedron(rad=1)
icosahedron(rad=1)

You can use it like this:

display_polyhedron(icosahedron(20));

That will render a icosahedron centered at [0,0,0], with a radius of 20.

Being able to set the radius is really handy as you can do things like nest them, or simply create them to the size you need. The fact that they're centered on the origin makes it fairly easy to rotate them around, to whatever orientation you like.

The .stl files here just show some casual renderings that can be generated with the test_platonic.scad file. Doing truncations and stellations is fairly straight forward. Even doing hollowed out forms, particularly with duals, is fairly straightforward as well.

The only thing that's not here is using the inradius, circumradius, and midradius for doing proper alignment of duals. But, how hard could it be?

At any rate, OpenScad now has a tidy little set of Platonic solids to play with.

UPDATE: 19082011
I have added some .stl files that are renderings of the various solids. The Dodecahedron is actually having a problem in OpenScad. I will debug that one and upload it when it actually works. A very strange bug.

UPDATE: 03092011
Replaced the platonics.stl, with platonic_set.stl. I have a better dodecahedron now.

A funny thing happened on my recent holiday. I built a nice 3V geodesic dome and covered it with a parachute, so me and the family could sleep mosquito free. Of course I used the Desert Domes calculator: desertdomes.com/ in order to calculate my chord factors so I could cut my wood dowels. But then I got to thinking...

The geodesic form of tesselation is certainly good for dome building, but it's probably also good for other modeling purposes as well.

This thing is a library of functions that will do geodesic calculations, written in OpenScad.

There's no pretty object to go with it. I'll have to use my handy dandy renderer and generate some domes. For now, it's the the raw routines.

First, there's some simple useful nuggets related to spherical coordinates:
sph(long, lat, radius)
sph_to_cart(s) - convert to cartesian
sph_from_cart(s) - create spherical from cartesian
sph_dist(c1, c2) - Calculate the chord distance of two points on a sphere

that right there is enough to do some fun geometry and GIS sorts of stuff. but wait, there's more!!

Pulling this book off the shelf: Geodesic Math and How to Use It

I went and created the following:

geo_freq()
geo_tri2_tri3()
octa_class1()
octa_class2()
icosa_class1()
icosa_class2()
tetra_class1()
class1_icosa_chord_factor()

These are the basics. The last one is what you really actually use to figure out chord factors, then you use those factors, multiply for your radius, and you're done. For those in the know of geodesics, it's relatively easy going from there. If you're not so familiar, a much more handy geodesic() module will be forthcoming in a subsequent release.

As usual, why bother with all this nonsense? The web based calculator at Desert Domes is perfectly usable after all... Well, that calculator generates domes based on the Icosahedron, Class 1, Method 1 style. That's not the only form in which a dome can be constructed. There are the octahedron, and tetrahedron base forms, and what about elliptical shapes, and who can forget triacons!!?

At any rate, I figure if there's a ready made public domain library to start from, people can make more interesting dome construction models, so here it is! I think it would be rather nifty if OpenScad had native support for geodesics...

Future additions will include more interesting methods/classes and things such as elliptical and 'free form' sorts of things. Then it will get really interesting.

UPDATE: 08082011
Added a blog entry to go with this:
williamaadams.wordpress.com/2011/08/08/geodesic-math-in-openscad-part-1-of-some/

UPDATE: 12082011
There is a bug in the 'clean()' function. So, if you're using the sph_to_cart() function, you'll get invalid numbers when you rotate past 90 degrees for your longitude. I'll update in a bit, but there's some other new functions coming as well.

I always have need for a good/better vertex to construct space frames.

This derivative thing just makes a few 'improvements' to the original design.

First of all, I've modularized the code somewhat. This doesn't make any particular improvement, but it will make it easier to see what's going on, and how to add to it in the future when more vertices are needed.

Second, being the slave to phi (1.618) that I am, I changed things like the thickness of the connector to be proportional to the radius of the rods that you're using (instead of a fixed value).

I've also made a change such that the length of the connector is automatically calculated proportional to the length of the rods that you're using. The base size is 10mm, and it grows by an appropriately 'phi' influenced length. So, the ones for a 36" rod, for example, are closer to about 20mm, rather than 10mm.

With these changes, it becomes rather trivial to make good new connectors for any size, by just changing the single diameter value, and the rod length.

I've played with a lot of vertex designs over the past few months. This is one of the most compact, and easy to utilize. I give props to Sjoerd de Jong for the simplicity of the design.

In the picture, the struts are 36" long. The overall height of the structure is about 8'. With this design, the fit is strong enough that you can actually assemble the thing with one person. If you've ever done dome development, you might recognize this is a 'good thing'.

Here's a more polished, production-ready update to the domekit 3d-printable geodesic connector system. We refactored the central hub to feature a rounded edge and use less material. The strutcaps are shorter while being more durable, and include an integrated thumbscrew (with captive nut) that locks the strut to the node. This makes the structure easier to assemble, because you're not trying to snap the balls into the sockets — just slide the strut into the shaft and turn the screw.

+ + +

please visit domekit.cc for more details

I made this geodesic dome as my first experiment using Autodesk's 3DS Max Design 2011. I was inspired by Buckminster Fuller and his domes. I exported it to .STL and scaled it up in replicator-G to print on the Makerbot ToM with Stepstruder MK6. It took 45 minutes to print. You can see more images at:

digitaltectonics.org/blog/?p=1052

I was worried that the top might collapse since there is no support material, but it held up.. The very top is a bit 'messy' and blended in, but it held up just fine. It is nice to see it build in rings getting smaller and smaller as it goes up.

EFFALO designed these nifty geodesic dome connectors and wanted to do a distributed manufacturing experiment by offering to pay $2 if you send them a part. I figured I'd send one, but I wanted my piece to be personalized. He helpfully supplied the openscad code so I added my bitmap module and added my initials and my logo on top.

this is a connector design for assembling a 2V geodesic dome structure. based off the wizardry of c60's original Dome Connector, we've improved the design by shaping the hexagonal connectors like hexagons, and the pentagonal ones like pentagons — making it much easier to visually differentiate between the two different connector types. additionally, we've added pairing notches above the 16° B-length struts on both connector shapes, to help accelerate assembly.

This is an scad file that will generate connectors for geodesic domes, hopefully.