New Corner Pillar Design

The tower I made back in October used 2x2 bricks stacked up for all the vertical pillars between layers. These are light and quite strong. The big problem with a stack of 2x2 is tipping. Even with some weight on them, they can be pushed sideways easily. I think I found a good solution to that problem. By using a different corner pillar design that has greater effective width I think it will be much less likely for individual pillars to tip over. The new design is still based on 2x2 bricks but every five layers a 1x6 is added in one direction. The next layer is another 1x6 at a 90 degree angle. This is repeated every five layers. At the other end of the 1x6s is a stack of 1x2s. Effectively each corner pillar is made up of three "sub" pillars a 2x2 in the middle and two 1x2 pillars at 90 degrees from each other. The three subpillars are joined into one piece by the 1x6 pieces. This structure is still very light which is important when a tower gets tall but is very stable in each of the two directions with the 1x2 subpillars. Since one of these new pillars is put in each corner, the overall structure seems much less likely to tip sideways at each level. I have a lot of 1x6 bricks but longer 1x bricks could be used like 1x8 or 1x10 for even more stability. This same approach could be used with the remaining pillars but I think it is unnecessary. The corners being less likely to tip seems to make the whole structure more stable.

Antenna

Tall buildings often have a slender antenna at the top. Inspired by that idea, I built a very light tower from Lego that could be put on top of any other solid tower. This one uses mostly 2x2 and 1x16 bricks. Three 2x2 stacks 30 bricks tall are connected up using two 1x16s. The groups are repeated eight times. It looks like an 'L' from above. What is amazing is that this simple approach resulted in a tower eight feet tall!

Slenderness Experiment

So how tall can a Lego tower be? Well it must depend on how wide it is. I decided to test some simple towers and see how tall I could make them before they collapsed. The first tower is made up of 1x1 bricks. I got it to 101 bricks tall before it fell. I tried this a couple of times and it always seemed to collapse just above 100 bricks. It was not steady way before then. 1x1 bricks just don't stack without curving all over the place. Using the 2.65 layers/inch approximation that is just over 38 inches tall. See the picture.

My next tower was 2x2. It is much more stable than the 1x1 towers and I was able to get it to 150 bricks tall before it leaned to far and collapsed. The entire tower leaned almost as a unit before collapsing. See the picture below.

The next tower had a 3x3 cross section. It was made of 1x3 and 2x3 bricks next to each other on each layer. I changed the orientation of them on each layer so it held together really well. It got to, you guessed it 200 layers tall. When I added another layer of 20 to the top it collapsed.

Finally, I made a tower with a 4x4 cross section using two 2x4 bricks for each layer. It got to 240 layers tall, less than the 250 layers I was expecting. This is over 90 inches tall, about 7.5 feet. No picture of the 3x3 or 4x4, sorry.


All of these towers suffered from lots of sway and curving. If you wanted to build a tower that could stand some vibration or wind probably would be a fraction of the collapse height. The pattern is intriguing, about 40 or 50 more layers for each additional "nib". Applying that formula for the 18 foot tower I made in October which was 38 nibs wide, it could have gone to about 50 feet tall. No way could I have made it to that height, it was swaying a lot already at 18 feet. Perhaps that should be the rule of thumb about 1/3 of the theoretical height assuming 40 layers per nib width. Given that, a stable 30 foot tower would need to be 72 nibs wide, a stable 50 foot tower would need to be 120 nibs wide, and a stable 100 foot tower would need to be 238 nibs wide. That would be a big tower, about 60 2x4 bricks on each edge.