Half term fun – building a geodesic dome, Part II
Posted by markharrison on October 21, 2007
Well, the first dome is now wrapped in cling-film, and outside in the back garden as a “science demo”.
The last two nights, we’ve had a light frost, and I’m hoping to be able to demonstrate that having what is effectively a small greenhouse makes a difference (even with an insulator as small as clingfilm), because it’s the trapped air that is ACTUALLY insulating the plants, not the glass.
Of course, it’s possible that the dew will actually rot the paper sufficiently, or the cold will brittleise the tape enough that the dome collapses. Also of these will also count as a science demo in the morning 🙂
However, spurred on by the success of Dome I, we made some modifications to the design, and now have Dome II.
Like Dome I, this is also made of paper – but this one’s a bit bigger. We’ve used the long side of A4 (29.7cm) as the A strut, which makes the B strut 26.25cm, so we cut that to length.
This time, rather than using tape for the joints, we’ve used “butterfly fasteners” (see pictures.) We solved the “paper too thick” problem by drilling holes through it first. These have given the newer dome a lot more structural rigidity, to the extent that it can quite happily support our duvet (again, see picture.) [Note that, for obvious reasons, I don’t normally put photos of my children on the blog, but this one struck me as sufficiently anonymous that it was OK.]
Like Dome I, it’s another “2V”… though later in the week (if the kids’ attention holds) we might make a 4V or a 6V as well.