For my final project, I am designing and building a chair using climbing ropes.
There's an emotional connection associated with ropes, for me at least. Tying in before a climb is an almost sacred act, a little ritual where both climbers bend the rope around itself, forming the shape that their life depends on. Then each checks the other's work, ensuring the rope does indeed follow that precise path; one that cinches down and becomes stronger as more and more tension is applied. It's a simple act, but vitally important; after leaving the ground, the knot is trusted with absolute certainty. Anchors are designed for redundancy, carabiners and protection are backed up by others lower on the rock. But there's only one rope, one tether to connect the climbers, both to each-other and to the world they come from. It's how I imagine astronauts feel before stepping though the threshold of an airlock. They check once more that their tether to humanity is properly secured, before stepping into the void.
I recently retired one of my favorite climbing ropes. I found a section where it had frayed almost all the way through to the core. It's the second rope I've retired, and I might be coming close on a third. Anyone who climbs for long enough ends up with a pile of old ropes, worn and pilled and frayed just a hair too much, so that tiny shadows of doubt creep into the mind of the climber. Those shadows are much more dangerous than any damage to the rope itself. Actual cases of ropes breaking due to overuse are very few and far between. But as you move above a potential fall, the thought that your tether might not be reliable is the last thing you want on your mind. And so it's safe to stop climbing on ropes once they've seen a certain amount of use.
But simply getting rid of a rope feels wrong. All those frays and nicks come from the incredible places its gone, all the memories its been a part of, all the friends it brought together. I still have the first rope I ever climbed on, and it has its place next to all my other gear. It's purpose is no longer to catch falls or haul bags or rappel. It's for running through your hands, feeling the worn texture of its fibers, and knowing that a small piece of every rock it ever touched is likely still imbedded within its weave. It's for remembering the adventures of the past, and dreaming about the ones to come.
That was a little piece a wrote a little while ago for a writing class. But I really do have a ton of ropes lying around, and living with six other climbers doesn't help. Nobody wants to throw away their old ropes, but they don't do much just sitting in a closet, even as a piece of nostalgia. So I wanted to use this project as an opportunity to make something useful out of all these ropes. I thought a chair would be a cool use of the rope, and I found plenty of examples online. My favorite is this one:
I like how the entire sitting surface is made using the ropes, and that it uses the slight stretch in the rope to allow it to deform to a person. I like how the ropes intersect past each other, but from the side they look like they pass right through each other. I realized after looking at this for a while that if I used this same technique but on curved lines, It would create a really interesting apparent double curvature that results entirely from the straight sections of tensioned rope.
To explore this idea, I made a simple grasshopper program to draw lines between four curves at equally spaced points. This allowed me to mess with the curves and try out different geometries. I like having the two opposite curves of each sitting surface be curved in opposite directions because it gives the appearance of switching concavity which I think looks really cool.
Once I had experimented around with the shape I wanted to create, I made a more complex grasshopper definition to create a whole chair. I still wanted to mess with the shape, but I needed to include the supports that would hold the curves in place, and the curves needed to have thickness with the ropes wrapping around them. This grasshopper definition makes pipes out of the boundary curves, then makes pipes between the ends of the curves. It also makes thinner pipes out of all the rope segments, and pipes that circle the end curves to look like rope wrapping around them. It also models the rope wrapping in an hourglass shape around all four curves. There's probably a much more concise way to do this, but I'm new at grasshopper so I used a new component for each piece of the frame.
I can control the radii of the frame pipes and the rope separately, as well as the number of times the rope winds around.
The rope is only for the renderings and to get a feel for what the chair will look like. It doesn't have to be modeled precisely. But the frame is what I need to make to create the chair. I decided that I wanted to use somewhat thin metal tubes to create this frame so that I could have as little as possible to interfere with the cool visual effect of the rope inverting curvature. I plan to use the 5 axis CNC machine to create the joints that will connect the vertices of the frame, and I'll use a pipe bender to bend the curved sections.
I made a lot of iterations to the design in this stage, But here's the one I like the best. All three curves are bent to the same shape, which will make them easier to manufacture. Also I think the symmetry looks nice. I decided to make the top tube straight so that the straight lines of the back contrast with the curves of the seat.
Once I make this chair I think it will be a lot easier to make more. It would be cool to have a bunch of the same chair with different ropes strung on them! I could make one for all of my friends.
For my other objects to render with the chair, I made a glass table, plates and a cool fruit bowl thing. I wanted to keep the same kind of modern, steel and transparent aesthetic between everything in the scene. So the bowl is a reduced mesh wireframe, and the plates are cage edited into squares wit pointy corners and rendered in reflective material.
Next I will tackle the fabrication of this chair. I may need to slightly redesign it as I find out what the limits are in using the pipe bender and the CNC machine. Right now the curves are just control point curves, which make a really cool looking conic kind of shape, but this may be hard to make with a pipe bender. I made another version that uses arcs instead, but it doesn't look as cool, so I'll try to make it like this.