On my latest MOC I want to build a round tower.
This is a minifig-scale build, and the tower is going to have a diameter of about 20/30 studs.
How should I go about building the "curved" wall of the tower?
Inspired by Zhaph's wall, this one is made with 1x3 bricks. It has a radius of 12 studs (24 studs diameter).
It is connected to the base by the last two studs on each end of the arc. The middle of the wall rests on tiles. To complete the tower you can repeat this module 4 times and use 1x2 bricks to connect them (replacing the 1x1 end bricks).
This would not make a perfectly round wall, but it's pretty close.
If you make a wall out of 1 x 2 bricks, where each layer overlaps by a 1-stud offset, and make the wall long enough, you can bend it into a smooth curve because of the manufacturing tolerance between Lego bricks.
This particular wall uses rings of 84 bricks.
I managed to put together the following set-up for the beginnings of a slightly narrower tower:
This gives me a radius of about 7 studs if I go as tight as I can, giving a diameter of about 14/15 studs. I would have used [part:3062b] but I'm not that organised (yet), so went with [part:4589:378] instead.
I'll have to see what I can do with 1x3's and cylinders to get closer to 20-30 studs.
There are dozens of photos on brickshelf of similar builds, and lots of techniques that fans have used. You can either look in the "recent" list or use the search field to find what you're looking for. You'll have to collect pictures from shows and wip builds to source your preference to what resources you have at hand but there a lot of pictures for future reference. I've learned more in five months of looking at that site than in ten years of experimenting at home!