DrJB

Really? ... Read again пожалуйста

Neat. I wonder if one can build two 'intersecting' tetrahedrons (with lego) i.e., one as you showed, the other using the 'other' diagonals... Will try tonight at home.

That's exactly it. The AA batteries are larger, and as such, will last longer. Now, there is a version similar to the 8878 that is rechargeable. It is mostly useful in situations where it's difficult to remove the battery pack.

You're absolutely correct. My typing and thinking were not in-sync that day :) The tetrahedron has 6 vertices, and these correspond to the faces' centers of a cube. Vice versa, the cube has 8 vertices, and those fit inside an octahedron, meeting the centers of the triangular faces. One additional fact, the tetrahedron and cube can be 'filled' with smaller replicas of themselves without any gap. This is obvious or the cube, but a bit more of a mental challenge for the tetrahedron. This is not true however for the dodeca/icosa-hedrons. For the octahedron, I'm not sure ...

Thanks. There are many lego renditions of these solids on the net. I did them in Technic, but other people have done them with system parts (plates and hinges) and others with bionicle/hero parts. In fact, at all the Brickworld events I've attended, there is always one person displaying many geometrical designs. Last year in Chicago, one person had displayed many 'Fractals-based' designs.

What, No Flex Axles? Seriously though, beautiful piece. Are instructions and a parts list available? ... No 'patience' to go through 18 pages of posts :)

Very nice! I wonder how they can achieve such 'odd' numbers. But then again, these are Certified Professionals.

Yes it was, as stated in picture below, from 1893. The gondolas have only 5 windows in the actual wheel, but 6 in the lego version. Not sure why. ALso, the actual build makes use of several 'illegal' connections (colored parts in my LDD).

The Museum of Science and Industry in Chicago is having a Lego exhibit, called 'Brick by Brick'. I'm debating where to put the pictures to share, but in the meantime here are few of a very large Ferris Wheel that uses both system and technic parts. The overall diameter is more than 4×32M. I'm also attaching an LDD that re-creates some of the sub-elements. I have few more high-res photos for those interested in more specifics. I believe the model is by Adam Reed Tucker, the author behind the Architecture Series. MSI Ferris Wheel.lxf

Here is a periodic repetitive structure, built with only 2×4 bricks. Not as elegant as technic connectors, but uses a single part. This is on display at Chicago's MSI (Museum of Science & Industry)

Thank you. I bought those orange globes a while black. I thought they'll make great street lamps ... first time I actually get to use them. Also, here is another rendition of the cube, this time an LDD screen-shot.

Platonic solids are solids whose faces consist of triangles/squares/pentagons only, with no mixing of shapes. It turns out there are only 5 such solids and they do find applications in many areas of engineering/biology/art. Many (before me) have built lego renditions of such solids, and I thought I'd give this my own 'spin'. I was 'lamenting' in a different thread as to the lack of suitable/colorful connectors and as such, I decided to 'decorate' my solids with some trans-orange and trans-blue parts. The 5 Platonic Solids are: 1. Tetrahedron - also called triangular pyramid 2. Octahedron - made up of 8 triangular faces 3. Cube - Hexahedron 4. Dodecahedron - 12 pentagons as faces 5. Icosahedron - 20 faces (trangles) In addition to these, there is the well-known bucky ball (soccer/football), or so-called 'truncated icosahedron'. In fact, the tetrahedron octahedron and cube are mutuals of one another, as are the dodecahedron and icosahedron. You can get one inscribed inside the other, and the vertices of one meet the centers of the faces of the other. Lastly, and unlike the beautiful renders in THIS thread ..., ... I opted for actually building the solids. The reason is rather simple: Most of these solids are not possible in LDD as some of the parts get 'bent' a bit. In the photos below, and in addition to the common connectors, I use the following parts: and The second part came with many Bionicle sets and you can still find it on bricklink And now, for the photos: All Solids together on the kitchen floor - to show 'relative' sizes Bucky Ball - Truncated Icosahedron Two Cubes (with bent edges) Icosahedron (truncated) Tetrahedron - this one can be built in LDD Dodecahedron - My favorite (maybe because of the 20 orange globes)

Agreed. They did some 'parts pack' in the past, but I have not seen any lately. The only set (I felt) was intended to 'replenish' the supply of red parts was the customized truck 42029. There, we got (few) connectors, frames, panels, suspension parts .... a MOCer dream come true. I hope they do read/monitor these threads and help us out.

Yes, I just finished it in LDD and it was not fun. Primarily the colors, then few errors throughout the instructions, like in the top views on pages 9 and 14.

I know what you mean. I have only 4 of such part (in yellow). Too few to build anything useful, too precious to give away :(

I've amassed a large number of technic parts over the years. But still, every now and then I find myself in need of large numbers of specific parts. While shopping on Bricklink lately, I've noticed that there is a smaller/shrinking selection of these connectors, especially in other colors than monochromatic (white/black/gray) These connectors are rather unique in providing multiple options for connection angles. Yet, with the advent of panels we see less and less of them. I personally never liked too much the 'paneled' looks of recent Technic sets, but it did not bother me much. If however such panels come at the expense of connectors, then ... ? Should technic revert to the 8448 style? Not necessarily, but a balanced look where both panels and connectors 'co-exist' would be an ideal balance, as in the 'other' red car 8070. Some Statistics to illustrate the point: Number of Connectors / Total Parts / % 8448: 98 / 1437 / 6.8% 8070: 42 / 1281 / 3.28 % Porsche: 56 / 2704 / 2.07 %

I once got two 13 gallons tubs, full of Bionicle ... for $30 both. Lots of Technic parts, but also many useless (to me) bionicle soft plastic. Still, it was worth it.

Very nice. I see many orange panels ... How many Porsche have you sacrificied recycled to build this truck?

Agree fully, this is really addictive. Reminds me of when fractal and self-similar geometries started coming out ... Keep at it!

On some construction machines, the bucket 'opens from the back' with hydraulics. I'm guessing for the BCE, some mechanism does the same function.

Anyone tried to build these in real life, besides the OP ?

A bucky ball (truncated icosahedron) is possible with these two parts. However, you can build it in real life (by slightly bending/forcing parts) but LDD won't let you. + or, alternatively + You'd need many parts. I have both built and displayed at home. I'll try to remember to take photos tonight. There are other ways to do build the bucky ball with system (non-technic) parts The one I find rather 'unique', is done by Hero Factory parts, and I believe an LXF file is available

I'm not sure. Most lego parts have one plane of symmetry (except for worm gears). The basic 'primitive' in this discussion (the many examples shown) needs to be 'not-symmetric'. In 2D space, it might be possible, but in 3D ... not so sure.

Many of the contraptions on here remind me of the various Mathematica solids ...

Thank you. The various projections shown in prior posts 'suggest' that the rows (of same color) are placed at the corners of a square, when in fact those rows are both at the corners and centers of such square grid. Which is what I meant by a 'grid twice as dense'. Also, my construction is likely to be more 'monochromatic' than yours as the most parts I have are white/gray/black ... time for bricklink.