There's an interesting connection between this and edge-notched punched cards (a special interest of mine), via a 1936 article in Nature (See <a href="https://www.nature.com/articles/137535a0" rel="nofollow">https://www.nature.com/articles/137535a0</a> .)<p>Quoting Kilgour's "Origins of Coordinate Searching" at <a href="https://books.google.se/books?hl=sv&lr=&id=4crkFsx73msC&oi=fnd&pg=PA107&dq=Origins+of+Coordinate+Searching&ots=J0kzu-NhED&sig=j5go5BOIJAeYLPFr2nUIvN3hESQ&redir_esc=y#v=onepage&q=Origins%20of%20Coordinate%20Searching&f=false" rel="nofollow">https://books.google.se/books?hl=sv&lr=&id=4crkFsx73msC&oi=f...</a> .<p>> In 1936, S. H. Clarke, of Britain’s Forest Products Research Laboratory at Princes Risborough, published a brief note in Nature reporting on an unexpected observation: Detection of relations of ‘‘recorded features’’ on edge notched punched cards with a particular feature already sorted.<p>> He had sorted a file of several hundred cards each listing a specimen of timber, by increases in specific gravity, and noticed ‘‘by glancing at the arrangement of the other notches . . . a distinct tendency for strength to increase with specific gravity’’ (Clarke, 1936, p. 535). He added that it was easy to recognize unusual correlations among notches.<p>The spreadsheet plot in this video is essentially the same as the image in the 1936 Nature publication!
There's an episode of Grand Designs (season 10 or 11 IIRC) where the couple building the home chose Japanese larch for the cladding for their home in Wales. The specialist lumberyard used some sort of handheld tool to measure the density of the trees (harvested in Wales) and it was extremely strong ... but the show also noted the strength could vary widely from batch to batch, depending on variables such as age, soils, etc.<p>Some details: <a href="http://www.cilfiegansawmill.com/forestry-wales/" rel="nofollow">http://www.cilfiegansawmill.com/forestry-wales/</a>
One thing that saddens me in the region I live is the lack of diversity in forests and therefore also in lumber selection. Quickly googling up some stats, 65% of forests are pine and 24% spruce. Only major hardwood would be birch (9% of forests), and its usually not available as lumber afaik.<p>One of my dreams (in the category "if I were a billionaire") would be to buy some large piece of land and plant all sort of interesting trees to create a sort of fantasy forest.
I’m not surprised by Osage Orange. There is a reason it is prized by bow (as in archery) makers.<p>Too bad they couldn’t do Yew too. That is another top bow wood.
Funny that he didn't record the moisture content. Wood that's been properly seasoned gets both denser and stronger. If the pieces here didn't have the same moisture content they could be up to 50% off in terms of strength. Different uses of wood also require different moisture levels, at different times of their processing.
I wonder how the "wood" 3D filament which is particles embedded in a brown PLA would compare. PLA is generally quite weak, this filament is only suitable for ornamental things.<p><a href="https://all3dp.com/2/wood-filament-for-a-3d-printer-explained-compared/" rel="nofollow">https://all3dp.com/2/wood-filament-for-a-3d-printer-explaine...</a><p>For the actual woods, I am not suprised by the ironwood. I once had a coffee table with an ironwood top and it was ridiculously dense and strong.<p>also, did you know there's an ironwood smuggling problem internationally?<p><a href="https://www.google.com/search?client=firefox-b-d&q=ironwood+smuggling+indonesia" rel="nofollow">https://www.google.com/search?client=firefox-b-d&q=ironwood+...</a>
This is really fun - but isn't information about the janka of most species already fairly accessible online? [1].<p>I always assumed there was a slight degree of strength variance due to age, humidity of growth region, etc - but maybe having your own tester might come in handy for certain structural engineering cases where accuracy is crucial.<p>[1] <a href="https://www.wood-database.com/wood-articles/janka-hardness/" rel="nofollow">https://www.wood-database.com/wood-articles/janka-hardness/</a>
So cool to see Matthias here on HN. He has a ton of other articles and videos where he tests different things like this. I encourage you guys to check him out if you haven't.
I would have liked to have seen Ipe wood tested. It is nearly twice the density as Red Oak, incredibly hard, and actually has a fire rating in the same category as concrete. <a href="https://www.wood-database.com/ipe/" rel="nofollow">https://www.wood-database.com/ipe/</a>
For weight constrained beam applications, both bending and compression failures are bending related (tension isn't).<p>Since bending strength is proportional to the cube of thickness of a beam, wouldn't less dense materials in practice always win out since you can make the beam thicker?<p>Ie the characteristic metric for beams would be stiffness / density^3
Doesn't the orientation and placement of the cut for each piece of wood have a huge impact on strength? If you've got a quarter sawn piece from heartwood you're going to get very different mechanical properties than plane or rift sawn sapwood. This and the orientation of the pieces in the tester doesn't seem to have made it into the post or the data sheet.
Around Seattle, madrona trees are indigenous. They are very strong, and are preferred to hold hills in place. There's one on my property that is gigantic and leaning at a 30 degree angle. It's been that way forever. It must be fantastically strong to hold that weight through storm after storm.<p>I wonder how they compare.