keggin and keggin-ish structures

    I'm on a 2-week break, since the store that my husband and I own is closed for the holidays.  Just when I had lots of free time, the beaded molecules folks (thebeadedmolecules.blogspot.com) posted a set of pictures that set me off on another structural journey.
The structure is called a keggin structure and wikipedia says it's the form of certain acid molecules.  I confess to not being much interested in the chemistry of it, but only in the geometry.  Geometrically. the structure is made of groups of 3 octahedrons that serve as the triangles in a larger structure.  The top  picture shows one such unit.  You can see on one edge (the top in this pic) there's a big triangle, and on the other edge (bottom) there are 3 small triangles that meet at a point in the center.   4 of these units, with the 1-triangle side on the outside and the 3-triangle side to the cente, form a  tetrahedron-ish thing.
    In thebeaded molecules site they showed 5 versions of this structure, identified by Greek letters that I don't have the font to write.  Picture 2 is the alpha version.  Till I made it, I couldn't tell how the others differed.  Turns out that in the alpha version, the triangles on the outside all line up with edges parallel to one another.  In the beta version one of them is point-to-edge.  Each of the others has 1 more triangle arranged point-to-edge till all 4 are that way.  But I had to see it in front of me before I understood it.  It's really hard to show a 3 dimensional structure like this well in a flat picture.  Even more so for me because I don't have 2 colors of bugle beads in the same length just now.
  Anyway, that's it for the Keggin structure.  But for me, since I'm dealing with it just as a geometric structure, not as a chemical thing, it seemed that the next logical step would be to take 8 of these triangle-ish units and make an octahedral version of the structure. So that's picture 3.  Then I took the 8 triangle version and made all the triangles point-to-edge instead of edge-to-edge.  That's the last picture.  I also improved things in that one by making the seed bead accents on the outside a different color from those on the inside of the structure, so that it's easier to read what's going on.
     A person just a little crazier than I  could also take 20 of the 3-octahedron units and make an icosahedron, but I think I've just about exhausted my interest in this.

bugle bead structures

   A few days ago, I wrote a post about the trouble I was having making structures out of long bugle beads, because of the sharp edge of the glass bugle fraying the fireline.  Gwen commented saying that when she uses bugle beads she adds a seed bead at each  end of it and treats the group of 3 like a single bead.  I said that might be an answer. Actually, though, it sounded to me like too many seed beads.  I was adding a single bead between each bugle, so as to make a slightly truncated tetrahedron.  The small flat face (a triangle of 3 seed beads) at each point of the tet added a bit of wobble, but not too much.  But it seemed to me, thinking of the first triangle you'd make in the tet, that doing it Gwen's way you'd be adding 2 seed beads between each bugle, and so you'd be adding that many more seed beads, and it would get more and more crowded where several tets meet.  Gwen, I hope you read this, because you were totally right and I was totally wrong.  Turns out that as you keep adding tets, it actually gets less crowded. I can't explain it, so I took a picture.  There are 2 structures, each consisting of 3 tets  The 1 on the left was done "my" way, making truncated tets.  The 1 on the right was done the other way.  Each one has 3 seed beads at each point where 3 bugles meet.  So that by even thought your 1st  triangle has 6 seed beads in it instead of 3, by the time you've finished a whole tet, the total number of seed beads is the same either way.  More importantly when 2 or 3 tets share elements ( in these the bugle bead in the center is part of all 3 tets) the structure done my way has 7 beads at the top and the bottom of that central bugle bead, and you can see they kind of bunch up.  When I did it Gwen's way there are only 5 and it all fits together much more neatly, even using #8 seed beads.    That's good for me, because, especially when I use the 30mm bugles, using #11s at the ends just doesn't look right to me.  To my eye a bugle that big needs a bigger accent bead.  Even here, with 20 mm bugles, I like the 8s.

   Once I figured that much out, I started thinking of my oxidized copper tubes.  Not that I need to protect the thread there, but I knew that sometimes it would be nice to add a bit of color.  The pic on the left is an earring (unfinished, obviously) using #8 beads in several metallic tones as accents to the dark gray tubes.  Here I may actually end up using smaller seed beads, as the diameter of the tube is small.  I don't have many #11s right now, so I used my usual 8s, and I think that it works.  I'll try #11s next and compare the results.  Anyway, this has all been fun.  Thanks, Gwen

bugle bead scaffolds

   I've been putting together applications for spring art festivals.  I decided to use mostly my tube bead pieces, because they're the ones that, to me, look the most different from what other people are doing.  So I did mostly my oxidized copper pieces.  I wanted to have one, though that had tubes with some color, so I bought some long bugle beads.  It turned out that the ones I liked best didn't actually have so much color.  As so often happens the picture on the website wasn't a totally accurate representation of the actual item.  I don't mean that as a criticism ( this was Shipwreck beads); I think it's just inevitable.  Anyway, even though they weren't very bright, I really liked them.  These are

30 mm bugles, so they really make a big structure.  I made these 2 necklaces right away.  The bottom one also has 15mm turquoise bugles.
    The hardest part was dealing with the sharpness of the glass beads.  I used fireline, and learned to push the new beads tight up against the old ones before I started pulling on the thread.  Even so the thread would be somewhat frayed looking by the time I got to the end of it.  That was partly because I  used very long lengths of thread (around 7') because, as you can imagine, making structures out of beads that are over 1" long uses up thread in a heartbeat.  On the bottom necklace, which was the first one I made, I went back again after I had made the whole thing and ran several threads along the whole length of the nceklace ( at top, bottom and middle) and put #11 beads between the bugles to ease the sharp angle.  I think they were too small to help much, but the extra threads should strengthen it enough.  On the 2nd (top) one I used #8 blue beads and put them between every bugle bead in each triangle.  They were almost too big, because when I got lots of triangles coming together at a point, I started to not quitehave room for the last ones, and things distorted just a bit.  The ideal bead would be as long as a #8, but with a smaller diameter.  Possibly a delica would do that, but I needed to do this quickly and didn't have any at hand.  Or 2 #11s, but I don't think I like that idea as well. Another possibility would be to use a bead reamer to round off the inside edges just a bit.  I only have around 150 bugles in each piece, so that wouldn't be impossible.
    Anyway, I had great fun making these, and I think they'll improve my applications ( I used the top necklace in the one I just sent in).  So cross your fingers for me!