Tag Archives: models

A light and strong structure

Strong but not heavy

Sky Yurt - model #3

Sky Yurt – model #3

To hold the Sky Yurt up in the air, and to attach the awning for the workspace I was going to need a strong core structure. But the Sky Yurt itself could be made of much lighter structural materials. It only had to hold itself together, like a pop-up camping tent. I was driving into Willsboro one afternoon and saw a backyard trampoline with a kids low play tent stretched over tramp. I knew about trampolines from my trimaran sailing. A few people jumping on a trampoline generate a strong downward force that needs to be resisted by the frame. So trampoline frames are built to be very strong. .But they are also portable and are pretty light for the stresses they have to deal with.

Using the trampoline frame to hold up the Sky Yurt

For the next model I went hunting for circular rings. Found what I was looking for in a craft shop – those hardwood rings that are used for needlepoint work. I made a new balsa wood and plastic straw model, and I really liked the look and feel of it. I was ready to build my first prototype. Now I was getting into the real building project. My scare-level increased to the point where I thought I might need to start wearing a metaphorical diaper. I asked my friend Andy Wekin – he was an artist who had gone back to school to be an engineer and he came with his partners Otis and Ezra (more on this team later) –  to be the consulting engineer.

Beginning to build the first prototype

Sky Yurt - PVC prototype

Sky Yurt – PVC prototype

I found a trampoline frame on Craig’s List and hauled it home. They are really available,  sort of like old hot tubs and spas. They are in those class of things that at the time seem like a good idea, but they stop being used (you don’t want your kid to break her neck) and  they take up space a lot of space in the outdoors. My friend Robin runs a preschool at a farm. They had a lot of PVC pipe that had been used in an irrigation project, and for a small donation I had my beams. I made hubs out of plywood and scrounged for PVC connectors that I could cut up and experiment with. I had SS wire from some of my old sailing rigs. Mostly I wanted to learn from this first structure -see if the basic engineering  would work, where I would need extra support and how the Sky Yurt structure would interface with the trampoline frame. And it started out looking pretty promising.

Working on the Ground – Living in the Sky

First concepts

Sky Yurt drawing #1

Sky Yurt drawing #1

I started making very rough sketches years ago. I wanted an open, circular, covered workspace on ground-level. The living space needed to be elevated, so you could almost walk underneath it, or at least see through it. I flattened out the tall tipi shape to make it more like a diamond, like in my early dowel and wire model. I decided the yurt would set on vertical uprights, doubled under each set of beams. The workspace tent structure would then radiate out from the eight-sided elevated yurt-like living space. The fabric cover on the workspace would need to be adjustable, so one side could be tucked down to block the wind, while the opposite side might want to be open wide and high to let in the warm early morning sun..

First models

Sky Yurt Concept #2

Sky Yurt Concept #2

I made a painstaking model out of dimensional balsa wood -held together with pins and light wire. That got lost in the shuffle over the years. The next model used clear straws for beams and joists, pipe cleaners at the outer ends of the beams, and cardboard and hot glue for the center hubs. I really liked the look of the design but some real concerns began to emerge.

I was still stuck on using vertical posts to hold the yurt off the ground. The whole structure was looking less like a tension structure. Those posts were going to need to be heavy and I was thinking that the whole structure was going to need to be pretty beefy to match it. And hell, this needed to be nomadic – meaning light and strong.

I ain’t no designer

You need to know as I walk you through this process, if you haven’t figured it out already, that my skills as a designer are severely limited. I can’t draw worth a hill of beans. I am dyslexic and have trouble with sequencing. I can get an idea, walk around thinking about it almost all the time – but I have to build the damn thing so I can begin to figure out if my “design” idea will really work. My neighbor Bruce, who has watch my “follies” emerge in the backyard laughed the other day, “I have heard of design/build, but I think what you do is build/design”. And he hit the nail on the head. That my process – build/design. It ain’t pretty, won’t work for a brick and mortar house, but with my Sky Yurt, I can take it apart, fix what doesn’t work and give it another shot.