
Slow, flexible and cheap: Six years of development to create a rubber hexagon - MichaelAO
https://medium.com/dome-kit/slow-flexible-cheap-5598ca91fb38
======
quesera
> Turns out, a slit really isn’t the best shape for the hole because if you
> don’t have the right kind of rubber, it can rip too easily. A circle is
> better because there’s equal pressure around the hole and it’s less likely
> to rip. I wish I had considered this sooner, but that’s what it takes to
> learn and that’s why I’m sharing this here.

Given the level of detail in the article, I'm led to believe that the next
moment hasn't happened yet..

What you really want is a slit with a pair of small circular holes, one on
each end of the slit.

    
    
      o--------------o
    

All the benefits of the slit without the tiny points where all of the stress
is focused, which is what causes the ripping. Adjust the size of the holes as
needed.

Common design trick for sheet materials, and should be straightforward to cut
with the same machinery.

Enjoyed the article.

~~~
objcts
great suggestion, i'll have to try this out. a big circle is more expensive to
cut than a slit, so this could save some money!

we cut our last batch of connectors with circles - not as much friction as the
slit but it's much more resilient. here's a photo:
[http://instagram.com/p/vSJ59WStiS/?modal=true](http://instagram.com/p/vSJ59WStiS/?modal=true)

~~~
shahar2k
I came here to make a similar digression but clearly am not the post to :)
interestingly though this is one of the reasons for serifs on fonts! In stone
carved writing serifs help remove corner stress and cracking.

------
Animats
The author read Domebook 1, the hippie dome manifesto. Kahn, who wrote that,
now says it was all a big mistake.
([http://www.shelterpub.com/_shelter/refried_domes.html](http://www.shelterpub.com/_shelter/refried_domes.html))

Buckminster Fuller's approach to domes was that they should be made from
factory-made components made to tight tolerances, made from modern materials -
Fiberglas panels, aluminum connectors, and neoprene gaskets. Such parts are
cheap when made in bulk. Domes made that way hold up very well. Some radomes
in the Arctic have been surviving winters for 50-60 years now.

The hippie dome movement, as led by Kahn, encouraged do-it-yourself dome
making from "natural" or even found materials. This doesn't work as well. A
dome has a huge number of edge joints, all of which are exposed to weather.
Making them leakproof is hard. Making them leakproof without tight tolerances
is very hard. The best solution the hippie movement ever achieved was to nail
shingles over the whole dome. Windows presented even worse problems.

A more subtle problem was discovered later. Although the basic geometry of a
dome is simple, what happens to a dome when sunlight heats one side but not
the other isn't. Large internal stresses develop, and this cycling from
relative expansion tends to cause leaks at joints.

The rubber connector is a nice part. It should grab tighter as the struts are
bent from flat to the dome shape. Getting the last struts connected, though,
might be a pain.

~~~
failrate
I've interpreted Kahn's main objections to be that the dome shape is difficult
to efficiently partition for human living. Any conventional appliances placed
against walls would leave large gaps. You could put some plumbing and
electrical back there, but it would still be inefficient use of space. That,
and the fact that conventional house designs are effective with natural and
found materials, and you have geodesics beat. That said, I'm constantly
looking at this problem because I feel that there must be some important
concepts that could be derived from geodesics without the dome aspect.

------
tjradcliffe
This is a really nice example of how a "simple" problem can take years and a
great deal of tinkering to find a workable solution. I've been thinking about
--and building--bookshelves for a lot of years, and only recently came up with
a design that I really kinda like:
[http://www.tjradcliffe.com/?p=1499](http://www.tjradcliffe.com/?p=1499)

The optimal balance between imagining and prototyping is a fascinating
problem, and seems to depend sensitively on the problem domain.

Prototyping even simple components is relatively costly in time, materials and
tooling, but gives you knowledge.

Imagination is free--it can often be done in time that would otherwise be
wasted--but it cannot create knowledge, and almost everything we imagine is
wrong.

Imagination can be fun. Prototyping is generally considered less so, although
the Maker community is working to remove that unwarranted stigma. We never
talk about "leaps of prototyping" the way romantics talk about "leaps of the
imagination", but maybe we should. One good prototyping experience can take
you a lot further toward knowledge than almost any amount of imagination.

~~~
nealabq
I did something like this in my garage, with chains hanging from the ceiling
supporting the fronts of the shelves. It was strong and adjustable.

But yours look much better than mine.

Do the cables ever slip where they're attached to the shelves?

------
objcts
what a delight to wake up and see this on the front page. thank you everyone
for your kind comments and thoughtful suggestions. this project has been very
close to my heart and i'm pleased to see this story become inspiring to
others.

[http://domekit.cc/kits](http://domekit.cc/kits) has more information,
pictures and links to buy one of our kits on Amazon.

~~~
brianpan
I love the kits. I didn't see an FAQ anywhere- what's the minimum number of
inexperienced people it would take to put together the small/big domes and how
long does it take?

~~~
objcts
at a casual pace with the help of a 3-5 friends, it might be about 15-30
minutes to raise a small DOME KIT. a big DOME KIT might take a bit longer, say
45 minutes with 5-7 people. we've seen highly-coordinated groups complete the
challenge in less than 10 minutes.

------
wallflower
I love stories where persistence over time pays off. Thanks for posting this.

This story reminds me of Sugru's story. If you have not yet read "A partial
visual history of sugru", it is well worth your time. Of course, this has been
posted to HN in the past.

[http://sugru.com/us/story](http://sugru.com/us/story)

~~~
mcescalante
thanks, this is a great read. I got a multicolor pack of sugru as a gift 2
years ago and I never would have guessed how much of a labor of love it had
been. And yeah, I thought it was pretty awesome right away.

------
scep12
I really enjoyed this writeup. The author's persistence and commitment to a
problem he found interesting reminds me of the energy I had before I worked at
a big software company.

~~~
dasil003
Or when my startup did a biz dev deal with a big software company, ugh.

------
xrd
His music is also amazing.
[http://parallelogram.cc/owneroperator/](http://parallelogram.cc/owneroperator/)

------
listic
I find it strange that you have designed your own dome CAD software, toyed
with 3D printing and other techniques, yet your final product is a ready-made
kit that only comes in two distinct sizes.

I thought you are aiming for a solution allowing everyone to build the dome
they want. You could be supplying the connectors (vertices), and users would
add the wood planks for edges (btw, would aluminum tubes be much heavier or
costly?). Maybe you could also provide ready-made planks of varying sizes;
that still would allow for many variants. Have you considered this?

------
sly010
I really enjoyed the article. It reminds me the sort of iterative search for
an elegant solution I often had to do during my design engineering MA. I
didn't appreciate "design thinking" at the time, it was too much manual work
for me for something that seemingly resulted in the same output. Now that I am
working full time for a software startup, I realise actually how much I miss
this way of working. I love getting lost deep in a problem space and making
something just a tiny bit better at every iteration. As a developer I
constantly have to remind myself that done is better than perfect, at least
until your company finds the one thing thats worth improving on. Product
designers often don't recognise but working as a designer is such a privilege.
Thank you for posting this. It made my day.

------
TulliusCicero
So, what are these domes intended to be used for?

~~~
wmkn
That, and what is the end result? Maybe I missed it, but in the end I only see
a picture of some rods, those connecting pieces and a cat.

~~~
dandelany
An earlier post explains it well:

[https://medium.com/dome-kit/building-
awareness-b89f1ee8b7fb](https://medium.com/dome-kit/building-
awareness-b89f1ee8b7fb)

"I’ve found there’s two main reasons why people build geodesic domes. Some
folks do it for shelter and others build them for pure enjoyment of the shape
itself."

------
ypcx
Total kudos. Now please move onto creating a dome that can serve as a shelter.
I believe, to start with, the connectors simply could be made from a thicker
rubber, but of course move will be needed. Thank you for your effort.

------
jsilence
Great work and a great article!

Would love to read any suggestions on how to design/produce a sheet of
greenhouse foil that fits snugly over the dome.

------
fernly
This is a very enjoyable account of patient and humble design work. Thank you
for posting it.

------
egypturnash
"Perfection is attained not when there is nothing more to add, but when there
is nothing more to remove." \- Antoine de Saint Exupéry

------
huuu
The Lean Startup, the work of Christopher Alexander, this article, all
examples of natural progressive refinement.

Great story.

------
Mizza
Great article, great product, great cat.

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dontpollute
This is going to result in a lot of plastic trash :(

