Edo TimmermansThe solids from Dimitri Tishchenko and Mathnetism inspired me to create some new solids, of which this video shows the first type. Making each of the 5 sizes of the solid shown in this video has its own challenge, yet size 1 and 5 are by far most challenging. In both cases polarity problems seem unavoidable, size 5 has the most interesting polarity problems though. A link to the next video showing the tutorial for that one will be placed here once available. As I thought I had seen a similar solid among Dimitri's work, I asked him if he recognized it. Indeed he has made a similar shape, but he wrote it isn't a solid (and it looks like the edges are straight): http://www.flickr.com/photos/38565795@N05/8158754106
Inward curved edge solid D surfaceEdo Timmermans2013-06-21 | The solids from Dimitri Tishchenko and Mathnetism inspired me to create some new solids, of which this video shows the first type. Making each of the 5 sizes of the solid shown in this video has its own challenge, yet size 1 and 5 are by far most challenging. In both cases polarity problems seem unavoidable, size 5 has the most interesting polarity problems though. A link to the next video showing the tutorial for that one will be placed here once available. As I thought I had seen a similar solid among Dimitri's work, I asked him if he recognized it. Indeed he has made a similar shape, but he wrote it isn't a solid (and it looks like the edges are straight): http://www.flickr.com/photos/38565795@N05/8158754106Statue/Award made of magnets (Nanodots)Edo Timmermans2020-02-01 | The bottom of this statue looks like a Nubian pyramid, made of similar units that increase in size from top to bottom. The top part in black magnets is a cube based build with Deltoidal Icositetraheron geometry, each side of the square is made with 4 units, the kind of also used for the pyramid. The golden part directly below it is half such a cube based shape with units one size larger.3D Surface of Tubes, the Schwarz P surface with a twistEdo Timmermans2019-05-13 | A tutorial for this shape will eventually be available on Dotpedia, I'm helping Dotpedia to create a large databank of tutorials. The shape is a variety on the Schwarz' P surface, in that surface each chamber is connected to 6 neighboring chambers with tunnels, the same is the case in this surface.Dual balance, cliff hanger note clipEdo Timmermans2018-02-19 | It is not a hard shape to make, yet the shape itself is cool because of the physics.ASMR Cool magnet physics: Switch, Stretch construction method, Rattle fidget spinnerEdo Timmermans2017-09-26 | About 2 weeks ago (before uploading this video) I discovered how to make the switch, in May this year (2017) I discovered the stretch construction method and today I surprised myself not so much by constructing but by using the rattle spinner! In the next experiment I found that there is a much easier way to create a rattle spinner with 2 simple 55-dots 11-tubes, still this one is very interesting because the rotating objects are not as round as a regular tube. The magnets used are Nanodots from Nanomagnetics.Trefoil knot made of magnets, famous from M.C. Eschers knot drawingsEdo Timmermans2017-04-30 | When making this knot out of a tube, the tube needs to be very flexible. I found a really cool way to construct the flexible tube shown here, this method will be available on Dotpedia in the near future.Bevel gear made of magnets (angle transmission)Edo Timmermans2017-02-05 | Made with Nanomagnetics constructors. To make the magnet constructions (oblate spheroids with some 8-dots rings added) is quite hard and to use them as bevel gear only works under the right angle, it requires some practice. But it's fun to play with!Single layer donut, pentagon symmetryEdo Timmermans2017-01-30 | Made with Nanodots Magnetic Constructors. For long, it was thought that it would not be possible to make a single layer donut with these magnets, as it would require an extremely complex design, except for the small donut with a tiny hole made with 2 30 dots-pentagon caps with opposite polarity, 60 dots total. Well, here it is, it's possible! It does require a tough and complex construction method, but the result, when made properly, has a perfect pentagon symmetry.Rim stacking combined Euro coins, 5 coins combinationEdo Timmermans2016-04-02 | This is my final video on rim-stacking coins. It has been fun, time for something else. It might be possible to improve on stacking 5 coins, most likely with 3 50-Euro-cent and 3 10-Euro-cent coins.Rim stacking Euro coins, cross stacking & new recordEdo Timmermans2016-02-28 | In the previous video coins were stacked rim on rim, yet in about the same direction. Cross-stacking them generally is a little more difficult, it is hard to find the exact middle for either front-back or left-right, as one has only one pair of eyes. Later in the video my new record with 4 50-cent coins is shown as well, followed by the completion of stacking 1- and 2-cent coins which I didn't show in the previous video. Thus, all Euro-coins are suitable for rim-stacking, as long as you select the right coins as there is a major difference in rims (flat or slightly rounded, narrow or wide) among coins made in different countries, years and even cities (Germany).Rim stacking Euro coinsEdo Timmermans2016-02-19 | Recently I experimented with stacking coins rim on rim. This video shows that this is possible with all Euro coins from 5 cent up. (I didn't try the 1 and 2 cent coins, they have a smooth rim just like the 5 cent coin, not a real new challenge) Especially wide rimmed 10- and 50-cent Euro coins are fun to play with.Tight chains of triangular bipyramidsEdo Timmermans2014-06-01 | The chain with the smallest dipyramids is the tightest. The largest has more room to move (relatively), there the bottom of each dipyramid can move below the center of the one below it, so these are not usable for a tower build shown with the smallest size ones at the end. A tutorial: www.youtube.com/watch?v=n_B0nSaEYRQTetrahedral & chain interlaced dodecahedron framesEdo Timmermans2014-05-22 | Making a dodecahedron shown here is easy, yet to interlace two of them is a tough challenge. Tutorial: youtube.com/watch?v=ykLNX1zHF8oChain of cuboctahedron framesEdo Timmermans2014-04-08 | The reason the cuboctahedra in the chain don't stick to each other is that the magnetism in the triangles and squares is directed in straight lines. As the poles of the magnets connect directly to each other, the magnetic force directed outward in these lines is weak. Besides that, lines from bordering cuboctahedra touch at a rather large angle, causing even less attraction. Thus, the magnetism inside each cuboctahedron by far outweighs the magnetism between two bordering ones, enabling free mechanical movement between them. Tutorial: http://www.youtube.com/watch?v=a2F-8IBIDug
Just for fun I added a few pictures of a running man chased by a chain of 7 cuboctahedra and a partial cuboctahedron, resembling a man being chased by a graboid in the movie Tremors. On Wikipedia: http://en.wikipedia.org/wiki/GraboidExtended (5x5x5) F-RD surfaceEdo Timmermans2014-03-24 | This video shows a surface that is a variety on Schoen's F-RD surface that, for now, I named the extended F-RD surface. In the F-RD surface, 1/8th of the unit cell generating the surface looks like a 3x3x3 cutout of Schwarz' D surface (as explained in the video). In the extended version of this surface, a 5x5x5 cutout is used as the 1/8th unit cell generating the surface. A full unit cell made of magnets with this method would require 48960 magnets, I don't have that many... Of course 7x7x7 or larger odd cube cutouts are possible too.Section of D surface unit forming F-RD surfaceEdo Timmermans2014-02-26 | Schwarz' D surface has chambers on both sides of the surface with 4 exiting tunnels going to other chambers, along the 4 directions of a tetrahedron. When you extend the 1296 dots unit shown in this video with the same logic it is made, it turns into the D surface. The cell forming Schoen's F-RD surface is very similar to a possible cutout of the D surface. I used this cutout to form an approach of the F-RD surface, in which on one side of that surface chambers have 8 exiting tunnels along the 8 directions of the faces of the octahedron, leading to smaller tetrahedral chambers, whereas on the other side of the surface chambers have 12 exiting tunnels, along the directions of the 12 edges of a cube. For more information on these surfaces, see: http://www.susqu.edu/brakke/evolver/examples/periodic/periodic.htmlShape with repelling rows of magnetsEdo Timmermans2014-02-09 | The rows of magnets repelling each other all have same polarity. This demonstrates that within a magnet there is always tension, in the sense that the magnetism tries to break up the magnet. Due to this force, magnetized materials are (somewhat) weaker in strength and more prone to be damaged then the same materials when not magnetized.Christian cross lattice made of magnets, star of David unitEdo Timmermans2014-02-05 | With the unit infinite slightly different lattices can be produced. In this video just 2 of them are shown. When all units in are placed in the same position the TT surface is produced, a lattice with straight triangular tunnels. The cell for producing the surface is simply the unit itself. A tutorial for the 72 dots subunit (of which 6 are needed to produce a unit) will follow later, a link will be placed in this video as well as in this description then as well.
When all units are placed such that each 2 bordering units mirror each other, a lattice similar to the I-WP surface is produced. The main difference is that there are various locations where 8 triangles meet in a point. These 8 triangles form 2 pyramids meeting each other at the top. When these pyramids are replaced with a square catanoid (a sandglass shape) the lattice turns into a valid continuous surface. The cell for this surface is a cube of 8 units combined, that each have had the same catanoid adaptation.
The cubic cell shown in the video is the 3rd possible option for a cubic cell with diagonal symmetry, where the lattice can be placed in 3D space such that in X, Y and Z direction the lattice is the same. For this reason, the pattern produced on planes between 2 touching layers of units turns out to be the same in all 3 directions. The pattern is shown at 2:51. The idea is to start with a 2x2x2 section of the TT surface, to which 3 1x2x2 sections of the TT surface in mirror position get attached. Then, add 3 1x1x2 sections, each touching 2 1x2x2 sections, again in mirror position. Finally add a single unit in the remaining corner in the 3x3x3 cube, in mirror position compared to the 3 1x1x2 sections. In this lattice also a catanoid adaptation is needed to turn it into a valid surface. In addition, to turn it into a minimal surface in some places 4 triangle (bottomless) pyramids must be flattened.
Finally, a cell of 3x4x4 units is shown. Because it doesn't have the diagonal symmetry described before, it generates 3 different patterns on planes between layers of units. These patterns are shown from 3:09 to 3:21.
The way to make the 36 dots subunit is shown in: http://www.youtube.com/watch?v=XLwYI7nVevgTwisted triangles tetrahedronEdo Timmermans2013-12-30 | In this video you see the result of a rotation of the faces of a tetrahedron, somewhere halfway on the way becoming an octahedron. When you rotate all the faces of any regular* or quasi regular* polyhedron (maybe even any convex* polyhedron with regular polygons as faces, but I'm not sure about that), until the corners of the polygons match, then you get a new polyhedron with more faces. When starting with a polyhedron that is not regular, then not necessarily all faces of the new polyhedron are regular however. For example, both a cube and an octahedron will become an cuboctahedron after rotating the faces and both a dodecahedron and an icosahedron will turn into the quasi regular isicosidodecahedron(12 dodecagons, 20 triangles). An isicosidodecahedron will turn into the quasi regular rhombicosidodecahedron(12 dodecagons, 20 triangles, 30 squares), which will turn into an irregular polyhedron with 12 dodecagons, 20 triangles, 30 squares and 60 times the same trapezium (Am. English: trapezoid) with 2 slanted edges of equal length. *the 5 Platonic solids are the only regular polyhedra *a quasi regular polyhedron has at least 2 different types of faces, they are known as Archimedian solids *when you draw a line between any 2 points in a convex polyhedron, all the points on that line are part of that polyhedron.Inset gear wheel, 31 unitsEdo Timmermans2013-12-26 | The fun part for me was that the wheel just fits on my turning table. What makes it interesting is the angle at which the unit connects, it rarely happens that so many units are needed to complete the circle (actually polygon).Variety on complementary D surfaceEdo Timmermans2013-12-13 | In larger builds adding units properly becomes very tricky. While adding some more units to the build shown in the beginning, something went wrong, a unit got seriously damaged, I couldn't repair it. Still it was nice to get the large overhang, so I still show the result further on in the video.
A tutorial for the units is shown in the previous video: http://www.youtube.com/watch?v=I2lD_JOS0Ts The small unit is completed at about 2:57 there, after which making the large unit is shown, built upon the small one.Solid complementary D surfaceEdo Timmermans2013-11-20 | The unit is a variety on the previous unit, leading to a different lattice. What makes this build very challenging is the placing of rows of 5 magnets as strengthening on places where you cannot properly reach them after placing. The outer surface of the structure represents Schoen's complementary D surface, hence the name.Tilted section of icosahedron latticeEdo Timmermans2013-11-14 | The lattice shown in this video is the same kind as the one shown in my recent video 'Unit sharing spheres lattice, irregular 6 pointed star units', yet now the 20 unit-spheres are stronger when placed on one of the pentagonal gaps without fortification. Because the tilted structure isn't strong enough to be made with 10 spheres I made the 10 fortified spheres version with the spheres having a unit at the bottom, making that build look similar as the one with irregular 6 pointed star units. The unit has been inspired by Mathnetism's hexagon solid.Hexagon lattice, 5 and 8 way chambers, Schoens H-T surfaceEdo Timmermans2013-11-02 | A tricky part of building this lattice, especially for a tall section, is that the bottom units must be placed perfectly straight to prevent them from partially shifting back in the flat 2 layer position they originate from. As a lattice, this is a variety on the P-surface, where cubic cells are replaced by hexagonal or triangular prism cells. In the triangular prism cell, there are 2 vertical (up and down) and 3 horizontal outgoing tunnels from the central chamber. When observing the other side of the surface, there are chambers hexagonal prism cells, with 2 vertical (up and down) and 6 horizontal tunnels exiting. This surface is known as Schoen's H'-T (hybrid) surface. See: http://www.susqu.edu/brakke/evolver/examples/periodic/hybrids.html#htCube of 8-sided trapezohedron symmetry unitsEdo Timmermans2013-10-26 | The unit is based on an 8-sided trapezohedron (=antidipyramid or deltohedron), as it has the same symmetry. However, there is a wide rather smooth path around the 'equator' of the shape. A 6-sided trapezohedron is a special case, known also as a rhombohedron as it has diamond shaped sides. Trapezohedra with more sides have kite-shaped sides. The lattice that is formed is not a regular lattice, when you continue to build with the same logic on all 8 sides of every unit then soon you would need overlapping units, which doesn't work of course. In principle this problem can be solved in hyperbolic space, but these units of magnets are not suitable for that. Therefor the build resulted in a cube, where in the center the units are only connected to 4 other units. This leaves a nice crystal look in the center of the build, that cannot be seen clearly in the finished build, thus I took various pictures while the build wasn't finished to show this. The unit is actually the result of forgetting how to build another unit that I had laying around for about 2 months. I found again how to make that unit, it will appear in the next video.Another lattice with Mathnetisms 5 ring unitEdo Timmermans2013-10-23 | Mathnetism has a video (link: see below) showing a beautiful lattice that essentially is a diamond shifted version of Schwarz' P surface. I found that the unit he used can also be used to form a stretched version of Schoen's complementary D surface, I just added some extra 3 dots triangles to fill some gaps to make the lattice stronger and more attractive. Mathnetism's video '5-ring Rhombohedron Lattice': youtube.com/watch?v=1gy07fN43hgUnit sharing spheres lattice, irregular 6 pointed star unitsEdo Timmermans2013-10-21 | Two types of hexagonal stars are shown, one to form the lattice with spheres of 20 units with triangular symmetry, the other star has rectangular symmetry and forms a sphere of 30 units.Giant sphere of magnets (with tutorial)Edo Timmermans2013-10-13 | One of the things I like about this sphere is that the double octagons that are positioned between 2 hexagonal stars are stretched so much. Also, it is nice that it is possible to lift the sphere without damaging it in spite of the size and weight. The reverse of polarity halfway the 20 bars was necessary to make the interior match the exterior. For making the 5- and 6-pointed stars you may find it easier to use the cardboard method I show in the previous video 'Many pointed double layer stars' Some other really large sphere approaches have been made with magnets before, that I'ld like to mention: Boyd Edwards has a neat one, Large Snub Ball (on Youtube), based on the snub dodecahedron, 2 layers, 4500 dots. Mathnetism designed 3 big balls, the smaller ones can be found on his Flickr account, the largest one is his Giant Truncated Dodecahedron Sphere (on Youtube), I don't know how many magnets (update: nearly 16000 he commented, it has a 19 cm. diameter if he remembers well). Finally the well known 1860 dots 'ultimate ball' that one can be found on various channels must be mentioned. I don't know who came up with that one first, probably theneoshow with a tutorial upload on Nov 5, 2010. If you know of another large sphere approach that should be mentioned here, please let me know.Many pointed double layer starsEdo Timmermans2013-10-12 | Making the 16-pointed star was extremely tough, it is very challenging already to make the 15-pointed one. It might be possible to make the 17-pointed version, if case you succeed then please leave a video-link showing it in the comments.Lattice with saddle shaped unitEdo Timmermans2013-10-07 | The lattice is a variety on Schoen's I-WP surface, I already have several of those on my channel, but I simply like the construction method needed to make the unit.Diagonal cube, 3rd type tetrahedral polarity corner symmetry, tutorialEdo Timmermans2013-09-28 | Magnenaut came up with an interesting way to make 2 types of solid cubes with a diagonal pattern that have tetrahedral symmetry of the corners. Shortly after seeing his tutorial I found how to make the 3rd type, a series in which the smallest cube has 3 magnets on each corner, which is shown in this video. (in one of Magnenaut's series the smallest cube has 1 magnet on each corner, in his other series each cube has 4 corners with 1 magnet and 4 corners with 3 magnets) A link to Magnenauts video 'Tutorial: Alternate Diagonal Cube (Zen Magnets)': http://www.youtube.com/watch?v=b6OocFw2FUsDisco sphere with 60 enneagons, big sizeEdo Timmermans2013-09-26 | And here is the big size I mentioned in the description of the previous upload.Disco sphere with 60 enneagons, small sizeEdo Timmermans2013-09-26 | The centers of the enneagons match with the vertices (corners) of a truncated icosahedron (12 pentagons and 20 hexagons). In the next video a similar shape is shown, made with 1 row larger enneagons.FungiEdo Timmermans2013-09-21 | In autumn in the Netherlands, fungi are common. Pieces of geometric art growing in the forest, mostly on dead wood.Near single stranded cube latticeEdo Timmermans2013-09-18 | There are various lattices that can be made with the little 12 dots unit, 3 are shown. The first one, the strongest, has units that resemble the cubic cell of the Neovius' surface. (see: http://www.susqu.edu/brakke/evolver/examples/periodic/periodic.html#neovius ) However, in the Neovius' surface each cell is connected with 3 other cells at each edge, while in my build only 1 other unit touches each edge of any unit (in the infinite version). The third one briefly shown, a dodecahedron, can be observed as a lattice in hyperbolic space.Rhombic dodecahedron lattice, intermediate of D and I-WP surfaceEdo Timmermans2013-09-11 | In Schwarz' D surface each chamber is connected to 4 neighboring ones with tunnels, in the I-WP surface (on one side at least) chambers are connected to 8 neighbors. In the rhombic dodecahedron lattice, when observing the infinite version, a third of the chambers (in my build the spheres) is connected to 8 neighboring chambers that are all part of the remaining chambers that all have 4 connections to 4 chambers with 8 connections. In my build there are 3 types of chambers, in an infinite version a third is only connected with 4 narrow tunnels, another third only with 4 wide tunnels and the remaining third part has 4 wide and 4 narrow connections. When leaving out all the spheres with narrow connections (and the narrow connections as well) then you get the D surface, when instead leaving out the ones with wide connections you also get the D surface. When adding a sphere in the center of each rhombic dodecahedron and connecting it with a wide tunnel to the 4 nearest spheres with narrow connections only and also with a narrow tunnel to the 4 nearest spheres with wide connections only, then you get Schwarz' I-WP surface.Enlarged spiralEdo Timmermans2013-09-07 | Mathnetism asked me if it is possible to keep adding bigger units to the spiral. This turns out to be a tough question to answer. I managed to add another 4 units, obtaining a build with over 9000 magnets. At this point gravity becomes a serious problem. Adding even more units seems possible, but for doing so one needs to lift the entire build which is really hard as the build is both heavy and easy to damage. Assuming one day someone will bring a million magnets into space, is seems that person should in theory be able to make the build much larger. However, another problem is that the 2 layer flaps of the units sticking out touch units of 4 sizes smaller and larger. This causes poor alignment that becomes really hard to fix quickly as units get larger. From a mathematical point of view, it is necessary to prove that for the inner or core spiral, the core distances between units differing 4 sizes remain the same or become larger as the spiral expands. It is too close to call to decide this from just observing the build physically. Proving this is not easy at all, some advanced trigonometry is required due to the angles involved. The core spiral of the build follows a 3D zigzag system that, when flattened, is about the same as the simplified spiral shown at the end of the video. For the amount of magnets used in the build: the 12 units are made with 9030 magnets, however some fortification was needed to support the weight, for which I used about 400 additional magnets.Spiral & spider dome with enneagon based unitEdo Timmermans2013-09-05 | The dome was made with size 3 units, I didn't try to downsize but probably that is possible. As not everyone has 3348 magnets, here is a table for smaller versions of the spiral: 1. smallest unit: 65 dots 2. size 2 unit: 130, total 195 3. size 3 unit: 213, total 408 4. 314, total 722 5. 433, total 1155 dots for a spiral with 5 units 6. 570, total 1725 7. 725, total 2450 8. 898, total 3348 The spiral can be made even larger, as shown in the next video 'Enlarged spiral'. 9. 1089, total 4437 10. 1298, total 5735 11. 1525, total 7260 12. 1770, total 9030Octagon based solid unitEdo Timmermans2013-09-01 | As the solid unit is a bit flexible, it is possible to form a 9 pointed star by pulling open the holes a bit. It is an interesting polarity phenomenon that when you place 2 magnets on top of the 2x3 to form the tips, that this can be done in both directions.Rhombic dodecahedron frame stack, avoid bad polarity systemEdo Timmermans2013-08-14 | This build provides proof for the fact that a simple tube of 4 magnets per layer can be made with different polarity systems.South Korea part 5 (final): SeoulEdo Timmermans2013-08-14 | There is a lot more to see in Seoul, it's a very large city and 2 days were just enough to scratch the surface.Trapezohedron, shifted D surface, large 1 layer build challengeEdo Timmermans2013-08-04 | The unit looks like a trapezohedron, the 8 faces are congruent (equal) kites. When you make a large solid version, you can expect some strange polarity problems at the points. It can be necessary to reverse the polarity of the octagon and square at the end, which doesn't seem to make sense at all. Making 1-layer large versions becomes more difficult for each next size, I wonder if anyone can break my record. (I didn't try the next size, I found the last one to be difficult enough) The kites on a solid trapezohedron are more flat, yet not completely flat, each kite is slightly bent. In the build of 35 units, the principle is that in an infinite version all units connect to 4 neighbors, just like in the D surface tetrahedral sections connect to 4 neighbor sections. Here, it results in a shifted version of the D surface. Using the same method, it is possible to make a trapezohedron with 10 kite faces, I didn't show that in this video though.Solid dodecagonal pineapple columnEdo Timmermans2013-07-20 | A smaller version of the unit is shown too, it is interesting that the smaller one can easily be made with double symmetry (a mirror symmetry and a symmetry axis), whereas I only managed to make the larger one with just the mirror symmetry. The larger one, however, can be used to make a solid column, as long as you like, with gaps on the outside giving it the look of a pineapple. As the column is 12 sided it is dodecagonal, but the dodecagon it matches is not regular.Brick lattice, manta unitEdo Timmermans2013-07-15 | The waving shape of the unit, made with 6 heptagons, resembles of the waving manta, hence the name I gave it. The large gaps remind me of the location of bricks in a brick building, so maybe I should have called it mortar lattice.Bubble icosahedron of flexible dodecahedraEdo Timmermans2013-07-10 | This construction is an improvement on my previous build 'Icosahedron of dodecahedra'. The unit now looks like an almost perfect dodecahedron except for the corners being a bit flat, also putting 12 of them together in icosahedron formation (when you connect the centers of the 12 dodecahedra, you get an icosahedron) can be done much better due to the units being both quite strong and very flexible. Of course, the 12 units can also be seen as the corners of an icosahedron. My previous video 'Icosahedron of dodecahedra': http://www.youtube.com/watch?v=E9ii2JI8M9cSouth Korea part 4, Jeju islandEdo Timmermans2013-07-10 | The Koreans are very proud of their island Jeju having 3 Unesco natural heritage sites. One of them is mount Halasan, an old volcano with a crater lake. When I walked the trail up to the top, it wasn't allowed to climb further on to the top to see the crater, I just got to the point where you can see the crater wall. The other volcano that is one of these Unesco sites is located on a peninsula at the east of the island. There it was possible to climb the cone, but there is no lake there, lots of birds and lush grass though. The 3rd site is the 4 km. long Manjangul lava tube cave located at the north east of Jeju, of which a 1 km. long section is open to the public. I got to all these locations by bicycle, I rented one in Jeju city. A link to the cycle shop: chejuhiking.co.kr More shops: see the link to a map showing various locations, at the very end of description. They picked me up at the airport and I got a tent with the bicycle as well. The first night I slept in the tent somewhere on mount Halasan at an altitude of roughly 700 meters, it was nearly impossible though to find a site to set it up... The next day I continued up on the mountain, walked the trail nearly to the top and cycled to Seogwipo. There I stayed in the Jeju Hiking Inn as advised by the site from Lonely Planet: http://www.lonelyplanet.com/south-korea/jejudo/seogwipo/hotels/hostels-and-budget-hotels A really nice place to stay for budget travelers! From there I cycled to Seongsan. There I stayed in a traditional sauna, very cheap, sleeping on a thin mattress on the floor, run by a very friendly old lady who doesn't speak any English. Not many people stay there, I found it a very interesting experience, definitely worthwhile. To get there: from the crossing of roads 1119 and 1132, take 1119 east towards the peninsula, at the large roundabout turn right, next road after 300 meters or so turn left, then it is the house nearest to the road after 150 meters. I stayed there 2 nights, the day inbetween I walked up the volcano (Seongsan Ilchulbong) and cycled to the harbour, took a boat to Udo island and cycled around the island. The next day I cycled to the lava tube cave and then on towards Jeju city, but the head wind was so strong that I ended up staying overnight in a guest house in Jochon-eup, near the coast, a great well kept clean place, very affordable and run by amazingly friendly and hospitable people. The address: coming soon, need to look it up. From there I cycled back to the bicycle renting shop, right at the coast, about 800 meters west from the famous dragon head rock. For more on Jeju island, see for example: http://wikitravel.org/en/Jeju More bicycle rent shops (5 lines of text for the link): https://maps.google.nl/maps?ie=UTF-8&q=rent+bicycle+jeju+city&fb=1&gl=nl&hq=rent+bicycle&hnear=0x350ce0858a6d79fd:0x4b9a8869e1919ce2,Jeju-si,+Jeju-do,+South+Korea&ei=4dbdUZmiKMjrswacmIDwCA&ved=0COQBELYDV edge tetrahedronal solid unit, 3x3x3 cubeEdo Timmermans2013-07-03 | Perhaps most surprising is the force of the 1x3x3 and the 2x3x3 build joining to become 3x3x3, shown at the end. I didn't expect that, as the connection between 2 units isn't that strong. I suspect it is caused by the cross connections of units of equal polarity.Rhombic dodecahedron of inward curved edge solidsEdo Timmermans2013-06-28 | The rhombic dodecahedron at the beginning is very similar to Dimitri Tishchenko's build shown on: http://www.flickr.com/photos/38565795@N05/8158754106 Dimitri wrote that the units in this build are not solid. As far as I know he was the first to build a rhombic dodecahedron by connecting tetrahedral shapes made with magnets. The units in my build are size 3 solids, a tutorial for them can be found in this video of mine: http://youtu.be/5NrvkFCikow Here, a tutorial is shown for size 5, for which a different method is needed.South Korea part 3, islands of TongyeongEdo Timmermans2013-06-26 | The islands mostly south of the city Tongyeong are part of Hallyeohaesang National Park. Several of them can be visited from the port passenger terminal on the north side of the harbour. There are various places to stay nearby the terminal. I stayed in a sauna about a kilometer north west of the terminal. These saunas are very affordable, around 10000 won (7 euros/ 9 US$) per night (2013). If you don't mind the heat, the thin mattresses and staying a large common hall then they are great low budget places to stay. The discomfort helps to get up early and make it to get on your boat around 6:30 in the morning. The good thing of an early boat is that you can take your time walking the trails, that require good walking boots (my sandals did the job but occasionally it was a bit risky). It is advised to be in good physical condition to walk these trails. Hansando island is different, there is an important historical site where the Koreans fought off the Japanese invasion from 1592-1598. Close to the small harbour of the island there is the Jeseungdang shrine, where almost all the tourist visiting the island go. There is a bus going around the island that is almost only used by the people working and or living on the island. I had a hunch to get on that bus and I was rewarded seeing a water deer, also known as a vampire deer. These deer (for sure the adult males, I'm not sure about the females and young ones) have sharp tusks, pointing backwards. In another picture I took from the bus, I was trying to picture the bridge to Chubongdo island. While the bus went over a bumpy stretch, I accidentally took a picture, catching a mirror that I had not seen on the edge of the road in which the bus is shown perfectly, a very cool lucky shot! Somaemuldo island was amazing as well, the track was steep but not too long, the views were awesome, a great bonus was looking at the pair of falcons that was most likely breeding there. I got to that island on a rather late boat, so I had to hurry a bit, but at least there was no morning fog, as there was on Yeonhwado island. Due to the fog I missed out on some spectacular views the 'dragon tail island' is known for. The trail was much longer, but totally worthwhile. For each island one visits, a full day should be planned. It can be worthwhile to stay overnight on an island as well, camping seems to be allowed and on some guest houses can be found. On the south of the harbour there is an excursion boats terminal with higher prices.South Korea part 2, BusanEdo Timmermans2013-06-16 | There is a lot to see in Busan, the largest harbour city of South Korea. This is just an impression, with one of the beeches, the fish market, and views from a famous tower in the center of the city. There is a good subway in Busan. I stayed overnight in one of South Korea's many sauna's. This one was named Vesta, located near Jung-dong subway station, near Haeundae beach, a beautiful place and much cheaper then staying in a hotel. The downside is that the common resting area has the television and lights staying on till about midnight and it is quite hot inside. There are very nice baths, massage chairs and other facilities thought. For more travel information on South Korea, you can check out my other videos, parts 1, 3, 4 and 5.