Beadwork, Polyhedra

Fractal Tetrahedra

So I was playing around with beaded triangles thinking about making some Sierpiński triangles. These fractals are simple to make – you start with a triangle (the first iteration) and remove an inverted half-size triangle from the centre, leaving three smaller triangles joined together to form the larger one (the second iteration). Then you do the same with each of these three triangles to make the third iteration. Keep doing this and you end up with a series of fractals like this:

beadmechanics_triangle

I was looking at these and thought – can you do something similar, but with tetrahedra? A quick search told me that yes, you can! It’s called a Sierpiński tetrahedron, or a tetrix. I went and found some beads and started beading straight away!

The first iteration of a tetrix is just a plain tetrahedron:

beadmechanics_tetrix_1

The matte black beads I used here are some of the first delicas I ever brought, over a decade ago!

The second iteration is where it starts to get more complicated! This is four tetrahedra, half as large as before, assembled to make one larger tetrahedron like this:

beadmechanics_tetrix_2

Each outer face of the tetrahedron is a Sierpiński triangle!

I was worried that joining the pieces together would be difficult, but I just followed a threadpath as if completing the last row of each missing triangle on the outer faces. This seems to hold the pieces together well, and also means the top piece rests on top of the others at each corner, so it doesn’t collapse.

The third iteration proved to be more of a challenge – at this point my tetrahedra were made up of triangles with only three rows. I split it up into four separate groups of four tiny tetrahedra. Each group is made with one thread, and each face is added by working inwards from an outline connected to the rest, rather than by making each one individually. It was quite tricky to do, and there were a few broken beads – I regret picking a matte finish for the edge beads! – but I managed to stitch it all together in the end. Here’s the completed third iteration:

beadmechanics_tetrix_3

At this point I had to stop since I couldn’t make the tetrahedra any smaller. Should have started with a larger tetrahedron!

Here’s the completed sequence of beaded fractals all together:

beadmechanics_tetrix_5

Definitely going to try this again – what’s the largest tetrahedron I can start with??

Beaded machines, Beadwork

Folding Cube

So I finally managed to finish the new machine I was working on! This time it’s not a kaleidocycle but a folding cube made using cubic right angle weave. Here’s a video:

I can’t find out if these cubes have a technical name, but they seem to generally be known as magic folding cubes. They’re actually quite similar to kaleidocycles, since they’re  a ring of eight linked cubes that can be rotated around back to the original starting point. However, they’re also very different since they alternately form two larger cubes during this rotation. I made the faces on each of these bigger cubes distinct – one is just the plain cubic right angle weave surface:

cube2_verrier

and the other has crystals embedded in it:

cube1_verrier

Each individual cube is a 4 by 4 block of cubic right angle weave, with a 2 by 2 gap for the crystals on three sides. Each of these cubes are joined to the two neighbouring cubes using modified right angle weave to make a hinge. I used size B nymo, size 11 seed beads and 4mm crystals (although 3mm or a flatter bead might have been better as the 4mm is just slight too big). I also found a curved beading needle a big help for some of the later rows!

If you want to try making one then I recommend making a paper model first for the hinge pattern – there are a lot of websites with instructions for making paper versions and having a model really helped a lot when I was putting it together.

Eventually I’d like to try making one out of 8 stellar octangula (a polyhedron that looks like two intersecting tetrahedra), since they have the same layout of vertices as a cube so could be fitted together in a similar way. Worked out that I’d need to make 192 triangles to do this though – might take a while!

Beadwork, Polyhedra

Warped polyhedra

So I’ve finally finished the pair of beaded shapes I was working on over the last few months! Here they are – a rhombic hexecontahedron and what is probably best described as a hyperbolic dodecahedron:

hexecontahedron_hyperbolic2_beadmechanics

So around the start of July I was reading about various polyhedra and I came across a rhombic hexecontahedron (the shape on the right) and realised that I could make one out of warped squares. I then realised that I could do a similar shape using warped hexagons and end up with the shape on the left. This isn’t really a polyhedron as the faces aren’t flat, but it’s similar to a hyperbolic dodecahedron shape, which is also known as spikey, the Mathematica logo (while a hexecontahedron is currently the Wolfram Alpha logo). I used Mathematica a lot when I worked in research, and spikey was one of the first ‘mathematical art’ polyhedra I encountered!

hexecontahedron1_beadmechanics

It seems that July was a month for making shapes out of warped squares though! While I was making this I saw Joy Davidson’s 3-star beaded box on facebook, and later saw Kat Oliva’s lovely patchwork rhombic hexecontahedron as well. I also ran across a photo of one on pinterest shortly after I finished it, which turned out to be a pattern by June Huber (Juniper Creek Designs). So it seems that I have just reinvented the wheel on this one!

hyperbolic2_beadmeachanics

I really like the hyperbolic dodecahedron, although it was at times challenging to make. I managed to make the tension a little too tight on some of the points and there were a couple of broken beads that had to be fixed by removing a section and repairing it, but I finially managed to finish it last week. I was also worried that it would be very difficult to stitch the last few pieces together, but it turned out to be much easier than I thought it would be (curved beading needles are an awesome invention!).

 

Beaded machines, Beadwork

Kaleidocycles

I’ve been making slow progress on beadwork over the summer, but I have had a bit of time to learn more about kaleidocycles and plan out my next project! Unfortunately I haven’t quite finished the current project (more on that soon) but meanwhile I realised I only ever posted a video of my first kaleidocycle and not any photos, so here it is in more detail!

kaleidocycle1_beadmechanics

And here’s the opposite set of faces:

kaleidocycle2_beadmechanics

Finally, here’s a view from the side:

kaleidocycle3_beadmechanics

Can’t wait to start the next one!

Beadwork, Polyhedra

Icosahedron

I’m busy making a new geometric sculpture, so I thought I’d take a break and take look back at an older piece. This is an icosahedron I made almost 2 years ago now.

icosahedron_verrier

I say icosahedron, but it’s really half way between an icosahedron and a dodecahedron. If you think of the beaded ovals as the edges, then you can find groups of three that make the triangular faces of an icosahedron, but you can also find groups of five that make pentagons and overall look like a dodecahedron. However, I based it on a icosahedron when I was making it, so that’s what I’ll call it!

Unlike my beaded dodecahedron, this piece has a chirality because of how the ovals are arranged to make each face. Chirality just means that a shape looks different to its mirror image. You can see that here – the ovals all point out clockwise around each triangle, but the mirror image would have them all pointing anticlockwise. One day I’ll make the mirror image version to match!

I’d also like to try this pattern as a truncated icosahedron (which is an icosahedron with the vertices cut off, so it’s made up out of pentagons and hexagons – like a football). I think it’d look good as a larger shape, but I’m slightly put off by the 90 edge pieces I’d have to make!

 

Bangles, Beadwork

Mookite Rick-Rack

Work has been slow on my next geometric shape, so I thought I’d revisit a piece I made about this time last year: a double rick-rack with a Mookite cabochon. There are some great bangles with tear-drop stones in the Contemporary Geometric Beadwork project — see the CGB facebook page for a photo of an amazing one by Cate Jones! When I saw this cabochon I knew what I had to make with it!

It’s a bit of a departure from my normal work as it’s the only bangle I’ve made in the flat and the only one I’ve made with size 11 seed beads instead of delicas. I really like the effect of the seed beads though, and their larger size made it possible to mix in a row of 2mm stones as well.

mookite_rickrack1

It’s a standard rick-rack built off an MRAW base, with a slightly larger peak in the centre than the sides. The bezel for the Mookite cabochon is also a simple MRAW band with a few rows of delicas and size 15 seed beads on the back and front. It’s joined to the band using a few extra stiches and beads at the sides of bezel.

When working in the flat there’s always the question of what to do at the ends. I decided to finish them straight and use that edge as a base for a few rows of herringbone stitch on both the front and back. I then joined the band to a simple toggle clasp with a couple of jump rings.

mookite_rickrack2

I was worried that it might not sit well when worn, but the cabochon seems to balance quite nicely and stops it twisting round. I’ll definitely be making more bangles with seed beads in the future!