Participative Wooden Structure

This week-end at the maker faire Moscow, I presented a participative wooden structure. Anyone could make its contribution to the construction.

This structure consists in only one part type. With these parts (all the same) two patterns can be created: The triangular pattern or the squared one.

As organizer of the Maker Faire Moscow, Fablab Moscow wanted something visible, interactive and fun. I wanted to work with wood and maybe the CNC router. Finally my boss showed me the work of Rinus Roelofs. This artist from Netherlands developed these types of structure since a long time and before him, Leonardo da Vinci already showed some sketches with this principle.

Step 1: Cut the Parts

Download the file named "rinusFace" and scale it at the size you want. Be careful: The thickness should correspond to the scale you use: Non scaled, the parts make 10 cm long and 3 mm thickness (first image). For the presented structure, I scaled 6 times (length=60 cm and thickness= 18 mm).

I used the CNC router (FlexiCam) to cut the parts in the Fablab. Caution: Let a frame strong enough to hold the part in place when machined. In my case I added screws between each parts and cut it one by one to be able to cut more part out of one board.

Step 2: Clean the Parts

The cleaning consist in two steps:

• Make a fillet (3 mm) on both faces with the hand router
• Sand the sides with the spindle sander

I found an efficient way to clean the edges with the hand router: I cut a template with the laser cutter which allowed me to hold the parts in place while making the fillet and save a lot of time (I made 120 parts). Instead of securing the part I secured the template to the table and inserted the part in it (see the images).

Step 3: Coat the Parts and Build

I applied a finish oil (Danish oil) with a cloth to protect the wood from humidity and dirt. This oil keeps the original aspect of the wood.

Conclusion

It was fun to see that people of all ages were amused by this structure. Also, a lot of research and exploration has been made by the users, everyone having its own way of building and using the structure.

Comments

[YaënD]

Hello and thaks for your crazy clevered thoughts !
what is the critical lenght for the bars ?
how big do you think it can be for a dome which can have 4 people in for exemple ?

[AdrienR]

Thank you.
I don’t know what would be the limit with this design but I think that you can easily make a half sphere of 6 meters diameter.

[instructaspark]

With your 100 struts, can you build a complete sphere in the triangular configuration? I began assembling it in CAD and as more of the dome is complete, the pattern doesn't mesh well (non-euclidean geometry etc). In reality, do the parts bind and prevent a full sphere? Or do they mesh? Nice work, BTW.

[AdrienR]

I think that it is not possible to close a complete sphere. For that, there should be a ratio between the part length, the triangle size and the sphere diameter but I don’t know what it is. I will let you know if I figure it out.

[Cantbliebthrers2derpzonhere]

Uggh! I've always struggled to build a dome using straight pieces and weird connectors. This direction is so much better to be going in! Thanks!

[AdrienR]

The parts are not straight, they are slightly arched. You could make a dome with straight pieces if you made the slots less deep.

[Cantbliebthrers2derpzonhere]

The curve is what makes it beautiful :)

[temper]

Clever stuff!

[AdrienR]

Thanks

[ewbray]

Have you ever calculated how large a structure could be constructed with and infinite number of members? For instance something like the framework for a Geodesic Building for 3rd world peoples or even off-grid builders?

[AdrienR]

The nice thing is that you can build this structure alone by adding the parts one by one all around (I can make the dome alone in 10 minutes).
I think the only limit for the size is the weight of the structure: At a certain point it will break under its own weight.

[Olaf_First_962]

I think using a template to hold the pieces during cleanup was brilliant! I thoroughly enjoyed this post! Your enthusiasm and joy at watching the exhibit being used comes through in your writing. Thank you.

[AdrienR]

Thank you very much.

[Gadisha]

Great, it looks nice and it's a fun concept that people can build the structure together even if they don't know each other.
Cool that the structure is strong enough for people to climb onto!

[AdrienR]

Thank you. It was also a nice discovery for me that we can climb on it.

[ColinF29]

Is there a size chart or template size that I can use to cut by hand and not cut not using a CNC?

[AdrienR]

Open the "rinusFace" file with any program that can handle DXF (illustrator or inkscape) then print the shape on paper. Report the shape on wood and make a template. Finally cut the parts with a jig saw or a band saw.

[JAMESM466]

This is a brilliant way for me to construct a temporary shelter. With the frame thus constructed, I could “skin” it with a large tarp. Thanks!

[AdrienR]

Yes and if you are in the forest you even don't need to make the slots, you can make something with simple lumbers or branches.

[KEUrban]

This is beautiful work. I find it fascinating.

Could you answer a few questions for me? Here's a dimensioned drawing from your provided DXF file:


1. When (in step 1) you specify a 10 cm part, is the above drawing dimensioned correctly?
2. How are the widths of the two slots (0.71 cm and 0.51 cm) related to the material thickness? You state that 10 cm part uses 3 mm material, and a part scaled six times larger uses 18 mm. What about material 19 mm thick (which is around a standard US lumber thickness of 0.75 inches)?
3. Is the radius of the bottom of the part related to the radius of a sphere that you could build from the parts?