Approximate Circles with Polygons

To continue with our circle building discussion, another way to build circles is to approximate them with polygons. When you have enough sides, polygons look round. For a smaller circle, octagon might be enough. For a larger circle, you probably need a hexadecagon (that’s 16 sided). I’ll focus on octagon and hexadecagon, since 135 and 157.5 degrees (internal angles of the two polygons) are the easiest angles to build in Lego. There are two ways to build polygon circles. One is to use click hinges, and the other is to use technic angular connectors. You can build circles of various sizes with this technique. See pictures below.


If you only want to build a ring, then you are done. But if you want a cylinder, you might want to cover up the build with plates. When doing that you’ll get gaps at the angle. To cover up the gap, you can add plates as shown below. Start with one plate and build outward. There will be a point where the gap is minimized.


Another trick is to fill the gaps with cheese wedges for even smoother edges. Various SNOT parts come in handy.


Once you are done with all of the sides, you’ll get a nice smooth circle like this.


On top of octagons, you can also add curves to make very smooth circles.


One drawback of this method is that you can’t create very small cylinders. To partially mitigate this, you can add the plates to the back of the bricks, see below. To use this trick, you need to have a way to incorporate the wider circles on the top and bottom into your creation.


Now that you have a nice cylinder, how do you seal off the top? To be continued…

Note: LDD file will be in the next post.


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