Just thought I would post this up so people could read it.bernard wrote:Here's a document posted on the national website for Wright Stuff: https://www.soinc.org/sites/default/fil ... iad5.0.pdf. The two events are very different yet construction tips carry over between the events. On page 5, from left to right you have: butt/end joint, butt joint secured with a gusset, lap joint, jap joint secured with a gusset. In general, increased contact between two pieces = stronger joint. I can't explain why a lap joint is stronger (probably some explanation involving wood grains) but the science backs it up.
In my opinion, towers are more complicated to understand. Bridges are simpler: https://www.youtube.com/watch?v=OYtY0BxXFgM. The upper section of the bridge is under compression, and the horizontal lower braces are under tension. What if we don't have the horizontal lower braces? Nothing will stop the bridge from doing the splits. What if we don't have the smaller braces connecting the larger compression members (difficult to see from the site, but clearly visible from the top of the bridge)? The larger compression members might shift differently, allowing tilting and shifting of parts = likely unstable. From what I've learned, a little shifting (i.e. settling) right as you add the bucket or load your first scoop is fine; but shifting later on is not good. Balance is important, and if a left member shifts differently from a right member making one of the two weaker, structural symmetry is broken (at least temporarily). And it's possible in that moment the tower/bridge/whatever breaks.
I hope this makes sense,
I have a followup question though, and that is this. Should we brace lap joints on the outside of the tower or the inside? Intuitively, I would think on the outside, right?