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Recently in *Fun Stuff* Category

Saturday I spent most of the morning getting ready and cooking for Kit's 30th birthday party. It was family-friendly for the afternoon, including pony rides!! In the evening after dinner we got picked up by the party bus for a pub crawl, stopping at The Ducks Nuts, The Durham, and PJ O'Reilly's in Tuggeranong. I had a pretty good time while some of the others got suitably silly hehe. The 80s music collection on the bus was pretty pitiful though, I struggled to find good stuff to play. There will be photos of my outfit soon.. :)

Sunday was just housework, jigsaw etc, and I helped clean up a little bit. Kit had *heaps* of leftover food which various people including us are helping her with heh.

So the dodecahedron and the icosahedron are dual solids. The icosahedron has 20 faces and 12 vertices, while the dodecahedron has 12 faces and 20 vertices. It means that if you truncate either one of them to the same point, you send up with the same shape - the icosidodecahedron.

I made the paper solid from a net from korthalsaltes.com..

And I made the paper geodesic version from Vince Matsko.. (If using his nets, you will need three pages of the pentagons, and one page of the triangles. The tabs for the five triangles making up each pentagon will go in the middle. The triangle is equilateral so doesn't matter where you put the tab).

Here's the two of them together..

Over the past few weeks I've been making the paper geodesic icosahedron pictured above.

As with all my other balls in the past few months, I got the nets from Vince Matsko's website. The problem with this model is his instructions aren't very useful if you don't have Magnus Wenninger's Spherical Models book:

*Not so challenging as its 8-frequency companion, this model requires just 320 individual spherical triangles of 5 distinct types. Bands are labelled numerically as in Figure 48 (p. 95) of Wenninger's Spherical Models. Although not individually labelled, the bands adhere to the following scheme: in Table 4, the arc in the third column of the list of bands is always next to the tab. You can easily check this by noting that in a circle, larger angles subtend larger chords, so you can measure chords to find out which angle is which.*

*The finished model will be approximately 14 inches (36 cm) in diameter.*

Vince's net pdf document contains bands for the five different triangles. But without Wenninger's book, you've got no way to know which band is which. So here's one I prepared earlier:

You can see from the diagram there are five different shaped triangles, numbered 1 to 5. This matches the pdf document on Vince Matsko's site. Also take note of the lettering - letters a to d indicate the length of each side (remember these aren't equilateral triangles! see Wenninger's book for more details on the mathematics of it).

The next line of instructions:

*Although not individually labelled, the bands adhere to the following scheme: in Table 4, the arc in the third column of the list of bands is always next to the tab.*

Again, without the book you've got no hope. And even if you do have the book, it can take a while to figure out what he actually means. Eventually I figured it out. Here's the table he's talking about:

Highlighted on the right is the "third column" he's talking about. If you look at the first picture from the book further up, you can see that triangle number 1 has "a", "a", and "b" as the lengths of its bands. And triangle 2 has "b", "d" and "d". And so on. The table above shows this as well. Now, in the table above, what he's saying is that the "tab" in the printouts is always next to the letter in the third column. So for triangle 1, in his pdf it will be a-b-a-tab. Triangle 2 will be d-b-d-tab, and so on. Here's what it will look like:

You'll note above that triangle 3 is asymmetric (look at the big triangle at the top to confirm this). Half the triangles are "left-handed" and half are "right-handed". If you were to print out all the copies of triangle 3 and fold them the same way it wouldn't work.

Here's the diagram from the book, but also showing the locations of the tabs once it's all put together, and showing left and right handed triangle 3.

Now the triangle above is just one "face" of an icosahedron. Remember an icosahedron has twenty sides. So you will need 60 bands for triangle 1, 60 for triangle 2, 120 for triangle 3 (60 left-handed and 60 right handed), 60 for triangle 4 and 20 for triangle 5. Using Vince Matsko's nets that's 10 pages for 1, 2 and 4, 20 pages of 3, and 3.3 pages of 5 (4 pages with a couple of leftovers).

But. If you were to print out the nets on A4 paper, the ball would be *huge* - double the size he says in his instructions. So I resized the images and pasted them into a word document. While I was at it, I flipped a copy of triangle 3 so the black lines would always be on the outside. Attached is my word doc with the nets that I used. It includes instructions on how many of each triangle you will need.

Right. So now we've got the design sorted, let's get started.

I printed each triangle on a different coloured piece of paper. And for triangle 3, I did the left and right handed triangles on different coloured paper (blue and green).

Next, cut them up. Each one took about thirty five seconds to cut.

Once they're cut, fold them up. I folded them so that the black line from the printout would always been on the outside. Each one took about twenty five seconds to fold. I did most of this in front of the tv.

Once they're glued into triangles (each one took about fifteen seconds), you can lay them out to see what they will look like before gluing.

I started a production line - got all sixteen little triangles for each face and put them together.

Then I put them together in the correct configuration, with all the tabs in the correct locations.

And then glued them all together. Here's all twenty faces glued:

Now for the really fun part - gluing all twenty faces together into a ball!

With six faces to go, it will fit quite nicely over your head.. ;)

And finally, we're finished!

A very time consuming, but quite impressive effort :)

I've been making stuff. All to be revealed soon :)

I was making stuff instead of cooking tonight, which means I'm going to need to get up early in the morning.. oh well..

Have also done a few entries on my new blog. Again, all to be revealed soon!

To much to do, too little time. Can I retire now? I could really use another eight hours a day to get stuff done...

First quarter 2017 jigsaws..

This Simpsons jigsaw was done by some of the guys at work, and late last year I found it in a bin. !! So I retrieved it and did it at work. It's one of those jigsaws where every piece is an "edge" so you can't start at the edges. I mostly did it by picking up a piece and putting it where it was meant to go. So it took quite a while. Tried to finish it by Christmas but ended up finishing it the first week of January.

This one David mostly did when he was up in January.

The next one I did at home was a jigsaw James and George gave me for Christmas or birthday in about 2004 or 2005. I remember starting it, ie doing the edges, when I was visiting Stu when he was living in Queensland. But I never finished it. This is why:

It took forever to do because I simply lacked motivation. Here it is finished:

After that I was super busy with trivia night and holiday planning.

On the Queen Mary 2 they have two big tables setup on either side of the ship in the games corridors where there's always jigsaws going.

I did quite a bit of this 1500 piece one:

And this 1500 piece one in the same series:

Someone else started this one of York Minster, but I spent a good chunk of an afternoon on it and finished it:

This 1500 piece one had been going by some others since Sydney. When I arrived in Hong Kong, there was just a little bit left and I helped finish it. They put it away, but later on it came out again. I started it one evening, spent most of the next day on it, getting it to about the point it was when I first came to it in Hong Kong. I was going to go back to finish it the next morning but was busy reading info boards, and when I did get back to it, a lady from Wales had finished it. But I feel like I did pretty much the whole thing :)

I helped with another couple of jigsaws on the ship but either didn't see them finished or hadn't helped enough to warrant a photo.

Saw this super cool thing today - Google Earth Timelapse.

"Timelapse is a global, zoomable video that lets you see how the Earth has changed over the past 32 years. It is made from 33 cloud-free annual mosaics, one for each year from 1984 to 2016, which are made interactively explorable by Carnegie Mellon University CREATE Lab's Time Machine library, a technology for creating and viewing zoomable and pannable timelapses over space and time."

Check out northern Canberra - Gungahlin and its suburbs have only existed in the past thirty years...

As always, I have a backlog of photos to post. Here's a couple from earlier in the year.

I never seem to have a shortage of Kit's animal photos..

These were the chickens all waiting for breakfast a few weeks ago..

Petal with her nails done..

About six weeks ago, Kit's friend gave her a bunny that was supposedly sexed by a vet as a girl. So Kit thought she'd see how they'd go keeping it together with her girl bunny.

Except Bonnie was a boy.

Whoops.

They'd been together maybe an hour before they made babies. They were born last week and are epic cute! This is them a day and a half old, after having survived the 40C day last Friday.

Another model I started making nearly three years ago was a paper geodesic octahedron.

Or, if you please, a geodesic hexahedron (cube).

It's a dual model because the model is made up of forty-eight triangles and you can look at it as eight faces of six triangles (octahedron), or six faces of eight triangles (hexahedron/cube).

This was another pretty simple model to make, with the net taken from Vince Matsko. You'll need to print eight pages of that net, but there's a catch: you need to make half of the triangles "left-handed" and half of the triangles "right-handed" - folding the strips "inwards" for half, and "outwards" for the other half. If you want to make a two-colour model, as I have above, you'll need to make all the triangles of one colour left-handed, and all the triangles of the other colour right-handed. Again, I stuffed this up when I was making it, and so I've had to make two models - oops!

A little while ago (crap it was nearly three years ago!) I started building one of Vince Matsko's geodesic dodecahdrons out of paper, based on Magnus Wenninger's Spherical Models. I finished it a weekend ago (after realising I'd stuffed up when I started and was trying to do it with three colours, but it looks a lot better with four colours, so had to make the white pentagons as you see below).

It's a pretty straightforward model to build. Each pentagon face of the twelve faces of the dodecahdron is divided into five triangles, so you'll need sixty triangles. Vince Matsko's net has twenty per page, so you'll need three pages. Although if you want to make different colours like I have you may need more and have some leftover. When you fold each strip, the little tab will always be right in the middle of the group of five triangles. I stuck each group of five triangles together, giving me the twelve faces, then glued the twelve faces together into the ball.

A simple and fun little model to make.