Twin Edged Dodecahedron

 

1 Almost there! Bamboo is clipped to jigs while superglue is applied to attach bamboo pieces to each other.

2 Later the jigs were removed and the whole thing stays together

These are some steps in making the plan: above is a dodecahedron net altered to show where "crossing" connections between faces should occur, below is a stereographic projection equivalent showing the numbering of nodes (1-20 purple) and the path of the bamboo through the nodes (1 - 60 black )

4, Done

5. Starting off: assigning node numbers using the plan.

6 The full set of central jigs for this polyhedron style, top to bottom are dodecahedron, icosahedron, cube, octahedron, tetrahedron hard to see in black.

7 Cube made using the same technique.

Hi

For a few days now I have been gathering parts to make a twin edged dodecahedron from a single knot.  I've known this is possible for a while, and have had the basic parts to make it designed and  / or on hand for a while. The key parts are a 20 sided 3d printed jig which holds m6 althread rod ( I have made these for all the Platonic solids, see 6 above) and a node jig to which bamboo rod can be clipped. 

There was quite a bit of work, designing the pattern, sawing allthread rod, attaching it to the centre piece, attaching and numbering jigs, then attaching and glueing bamboo, and finally jig disassembly.

I'm finishing writing an article on these, for the current draft version, see here , and I have done a few blog posts such as this as well. Bit of a slog getting the article finished as its all computer work and not the light relief construction brings.

regards steve nurse

Update June 4

With the full jig available and ready to go, I thought it a pity not to keep going and make a few more dodecahedrons. This time I planned for a different switching arrangement (see article in link above) with 6 twin -  circle elements made of cane, each in a sort - of figure of 8 pattern. One of these is finished now and I plan to make one more. The one I have made uses 6 3d printed plates to contain and tidy up all the basket cane loose ends. 

The 2mm basket cane I use came from a marine supplier. The bundles have to be separated into strands, and the strands are just long enough to make the figures of 8. Mary took some of the pictures.

Update June 26

I have now almost finished 2 lamps for the exhibition  " design fringe ". Some of the diagrams presented above have been used to decorate the shade. The bottom diagram was shown above but now includes a couple a new feature which shows where the path for the cane is predetermined, and there's no need to look at the guide to work out the next step. Firstly, the path is determined by the numbers in circles where the node numers mtch up with the step numbers. This breaks down after a while, but then later if one potential side of the cane's path is occupied it has to go through the other - this is shown by squares around numbers.

Pollution from Golf Tees

 

Golf tee remover (left) and golf tee (right)

Hi

For part of this year, I have been engaged with finding golf balls washed up on and in our local river bank, and making art and structures with them, for example here. A chance sighting of a random golf tee had me thinking "are golf balls the only direct pollution caused by golfing?", and the answer seems to be a resounding "no".

Golf tees (small platform for raising a golf ball above the grass, so it can be hit more easily) seem to be another source of pollution from golf courses. About 7 (see here) tees can be broken per round of golf. Some of these are made from plastic, but some from biodegradeable organic materials , while others are designed not to break and therefore should never be left behind. Whatever the tee, they are likely to float and so take a different path to golf balls when washed away. Bouyant tees seem more likely to float away and reach the open ocean than golf balls which sink.

The harm golf tees cause in the ocean has been documented anecdotally, but a widespread survey would be hard to do and involve examining the gut contents of thousands of birds and sea creatures to reach scientific conclusions. Nevertheless, some anecdotal evidence is strong such as: 

Golf tees and other plastic pollution implicated in seabird deaths, Los Angeles Times, 2006 

Shearwater bird ingested golf tee, Papers and Proceedings of the Royal Society o/Tasmania, Volume 142(1), 2008

Turtle ingested golf tee, A citizen's guide to plastics in the ocean: more than a litter problem, 1988

Beachcomber Matt is on Instagram and is a UK collector of ocean pollution, who picks up golf tees and other pollution and uses the hashtag #golfteeatsea  . As well as golf tee pollution, he has recently highlighted Australia's recent banning of disposable vapes as a good move. That is not for the health of Australians but the health of the planet!  We just don't need more plastic crap (disposable vapes) that end up as non-recycled items in rubbish and in the rivers and oceans.

An Australian golf publication recently reported on golf tee pollution issues and posted about a club banning plastic tees. It would be good if more golf courses followed their lead, better still, Australia could ban plastic golf tees.

Regards

Steve Nurse