Your diagonal bracing pattern is not very effective. Generally speaking, in towers and other similar structures where members mainly carry tension and compression forces, you need to avoid having rectangular patterns without diagonals. Put differently, it is best to model and build the tower using triangular patterns only.sj wrote:I have a couple of questions...
Does this suggest that the top is swaying/bending and needs to be reinforced with more diagonals?
Right now our tops have horizontals 1/16 x 1/16 every 3 cm and diagonals for every 3 of those so like:
____
|\__|
|_\_|
|__\|
|__/|
|_/_|
|/__|
|\__|
|_\_|
|__\|
|__/|
|_/_|
|/__|
Excuse the ASCII art.
The diagonal goes over the middle 2 braces without connecting (no glue).
Your chimney consists of four segments each having one diagonal member (connecting a lower end to an opposite upper end of the segment). However, each of the rectangular panels (you have three of them in each segment) is not individually diagonally braced. That is a problem!
When a rectangular panel is not properly braced diagonally, its opposing corners would have an easier time to move relative to each other. That, you want to avoid, or, minimize. That is why each rectangular panel needs to have at least one diagonal member for restraining the movement of the upper corners of the panel relative to its lower corners.
Also, with respect to weight (of the wood only and not the glue), your diagonal pattern is not offering that much of an advantage over the standard Z pattern. By my estimation (assuming a 4-cm wide chimney) you have about 58 cm of diagonal bracing for each side. If the Z pattern were to be used for the same chimney, about 60 cm of diagonal bracing would have been needed.
)
