Picture of Building beyond the scale of 3D printings
I start this project because I wanted a way to build these structures beyond the size capabilities of most 3D printers. It's also substantially cheaper to substitue dowels, which cost about $0.02 per cubic inch, instead of printing the straight sections.

All the dimensions given are specific to the form I built, any of them can be altered to fit your needs.
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Step 1: Wireframe

Picture of Wireframe
Build a wireframe. I built mine from an analysis of the motion of drinking coffee. I will elaborate on this process either in a later Intractable  or as addition to this one.

Step 2: Tubes

Picture of Tubes
Before going beyond the wireframe it is extremely helpful to make some layers for organization. I used these

Wireframe (original curves)
Inner pipes ( slightly large than the diameter of the dowel)
Outer pipes ( Inner tube + wall thickness of connector)
Joint Cutting Objects (set of spheres to make consisten connectors)
Dowel Cutting Objects ( optional layer)

Before you start designing your model mesure your dowels with a pair of calipers. It is a sad realization when you print out all your connectors to the size the size the dowel is listed as and the piece don't fit. 

I used quart inch dowels with diameters that vary between 0.24"-0.25", so I used 0.26" as the inner connector diameter. Before building any pipes, make sure none of the curves are joined. The angles between curves causes interesting but troublsom irregularities in the connectors. Select all the curves, use the Pipe: Rounded Caps command, and then move all the pipes to the Inner pipes layer. Hide the layer.

I built the connectors with a wall thickness of 0.05", making my outer diameter 0.36". This is wall thickness should be adequate for most models, but might need to be adjusted depending on your situation. Repeat the same process as the inner pipes to create the pipes for the outer diameter.
JamesF35 months ago

Thanks for the great advice, the slight offset for the rounded end union works like a charm!

Blair Qiu2 years ago
I still didn't know what's the function of this, otherwise i view all the comments from yours. Could i have more pls?
DuncanParks (author)  Blair Qiu2 years ago
The piece allows me to visualize the space I don't occupy. It's useful to me in exploring how space could crystalize around common activities. The piece really exist only as a physical realization of these ideas. Despite my piece not serving a utilitarian function, this technique for building structure could be used for any number of practical applications.
RanaLoca2 years ago
i like this whole thing but what was the reason for making this?
DuncanParks (author)  RanaLoca2 years ago
To explore the space we do not inhabit when preforming ritual domestic activities. I can still drink coffee at my coffee table, but I now have a visual dialog with the space I normal would not interact with.
sunnycanuck2 years ago
Very interesting, I'm thinking how to do something similar but with code in OpenSCAD. But like the other comments, I'm really interested in what you plan to do with this... tracking coffee cup movements?... please tell more..
DuncanParks (author)  sunnycanuck2 years ago
I'd be interested to hear more about the similar process you're trying to do in OpenSCAD. I am still exploring different ideas to pursue with this process, this iteration was primarily to see how the physical construction would work.
studleylee2 years ago
Cool and weird simultaneously! What made you think to track the
path of a coffee cup :-). I like this do more.....

DuncanParks (author)  studleylee2 years ago
This project was an effort to visualize the space we don't inhabit in our domestic setting. Drinking coffee at a coffee table seemed appropriately domestic to investigate.
way772 years ago
Is the program you're using the same as Rhino OSX, which is apparently only available as a beta? I love the idea of integrating printed parts with wood components and I'm wondering if I can do this using Sketchup.
DuncanParks (author)  way772 years ago
I am using the Rhino OSX Beta. I don't know if it's possible to duplicate this process in Sketchup, but if I end up figuring it out I will let you know.
Good one! I see you are into structural shapes as in architecture.To help you solve some of those complex internal structural supports. Insert floor levels into your design,but no supporting wall or roof supports .Dunk a WIRE hand model into Kids bubble blowing solution and all mathematically correct internal support structures will become visible on removal. All loading averaging out. Take a picture ,then work, backwards.(Reverse Science)
sitearm2 years ago
@DuncanParks; Hi! I like your detail on Boolean Unions and computer screenshots. I like in Step 1 where you spelled Instructable as "Intractable" - a hint of the upcoming required patience ; ) Cheers! Site