Testing the strength of different wood species
woodgears.ca
woodgears.ca
Quoting Kilgour's "Origins of Coordinate Searching" at https://books.google.se/books?hl=sv&lr=&id=4crkFsx73msC&oi=f... .
> 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.
> 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.
The spreadsheet plot in this video is essentially the same as the image in the 1936 Nature publication!
https://www.youtube.com/watch?v=MBwP3YOxw3I someone made a video about it
I made some of my own edge-notched cards using a computer-controlled stencil cutter. Here are some pictures - https://twitter.com/nathanbroon/status/750465911241502721 .
I had the idea to present it at a Chaos Communication Congress. Then life (a.k.a having kids) intervened.
Some details: http://www.cilfiegansawmill.com/forestry-wales/
That means that fast-grown oak or ash is actually stronger than slow-grown. As you look at a cross section of the wood, slow-grown wood has a much higher amount of void space than fast grown.
As I understand it, the southern longleaf pines are the opposite. Because of how their growth rings are formed, they have alternate layers of more and less dense wood. Slow-grown has a higher percentage of the dense, stronger wood. On this point I'm speaking from reading, not firsthand knowledge. The only SYP we get up here in the northeast is pressure treated. PT works totally differently because it's so damned wet and I don't use much of it either way.
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.
That's the thing, I'm not in NA, so pretty much any hardwoods available here are "exotic" imports.
"Identifying wood is not easy for a number of reasons. First, there are hundreds of different species of trees in North America. Second, the wood of many species looks very similar, if not identical."
I have worked an "exotic" lumber dealer that can definitely offer different species and grades of wood from all over the world -- including CITES (endangered species list) lumber with the proper certificates. But their customers are typically woodworkers that want a specific species for a specific look. So it's usually cabinet and furniture makers etc.
I have also worked at a "discount" industrial lumber distributer. They are selling wood to be made into pallets or used at a construction site for bracing. In those cases, the hardwood species are a lot less important. The customer just needs something much stronger than the standard SPF.
It's a fascinating industry. I learned a lot working that job -- even tho I was just implement their ERP systems.
As small agriculture consolidates and goes out of business, some wacky rich guys buy farms and turn them in legacy tree farms.
I grew up and went to school in a rural area of NY, one of my old friends maintains properties like this for clients as a side gig for his farm work. The area was selected to benefit from climate change.
In one case, just in terms of black walnut trees, when mature in 50-60 years, there is the equivalent of $10-12M (at todays prices) worth of timber for the owner’s descendants. The trust structure saves cash on taxes as well.
That plot is (measuring, mathing)... about 3 acres. https://www.profitableplantsdigest.com/growing-walnut-trees-... puts it at $100k/acre.
> For those with time and patience, a living legacy of walnut trees can be a priceless gift for children and grandchildren. According to professional timberland investors, the average return from a stand of walnut trees is 14 percent a year, with no taxes due until harvest. That beats returns on bonds, stocks and most other investments handily, and with intercropping, growers can even produce an income while the walnut trees continue to grow.
Even for normal people, some of these properties, especially defunct dairy farms are tragically cheap and not too polluted. My dad bought one for hunting and fishing purposes when he retired and made a modest income by leasing the land for hay. Not much, but enough to pay the taxes.
Also the reason for more monocultural forests like that is because the soil is high quality. If you had really low quality soil (like in the Amazon) you would have developed a lot more biodiversity
Here in Michigan the species diversity of our forests has been declining due to disease. Elm, and now Ash and Beech have all been dramatically impacted by imported diseases.
Too bad they couldn’t do Yew too. That is another top bow wood.
https://www.texasmonthly.com/being-texan/osage-orange-histor...
https://www.wood-database.com/wood-articles/bow-woods/
But in the comments, someone identifies "speed of cast" aka "self-fling speed" (!) as the key metric for bow woods, and he doesn't have European Yew, but according to that, Pacific Yew and Osage Orange are also pretty much the same!
A favorite quote from these types of engineering analyses.
https://all3dp.com/2/wood-filament-for-a-3d-printer-explaine...
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.
also, did you know there's an ironwood smuggling problem internationally?
https://www.google.com/search?client=firefox-b-d&q=ironwood+...
PLA is also stiff, among the stiffest of common printing materials.
It is quite strong for its weight.
https://www.mmscience.eu/journal/issues/november-2020/articl...
I have prints that have seen hundreds of pounds of force in use with no problem -- printed on $200 printers with $18 filament.
As a general rule, you will get best results if your part is printed so that the force this in line with the layers, not perpendicular to them.
For something like a $300 printer you generally have a choice of pla, something like sainsmart tpu for semi flexible, and abs if you can print with ventilation.
I was always confused after that experience why there isn't more ironwood furniture, and just assumed it's because it's too difficult to work with.
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.
[1] https://www.wood-database.com/wood-articles/janka-hardness/
I remember the days when YouTube videos were automatically flagged as "shallow" by the HN code!
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?
Ie the characteristic metric for beams would be stiffness / density^3
Is gluelam lighter?
It would be interesting to see, at least for a few species, how the placement of cut affects the results.
I often wonder what society would be like if we treated engineers and scientists like we do sports and entertainment and what you said I think falls loosely to into that realm of thinking.
[Scene: Outside Conference Centre. Scientists from all over the world arrive. Photographers take photos of them and fans in the crowd wave papers for them to sign.]
Woman #2: [shouting] I love you!
[Farnsworth steps out of a limo. Joan Rivers' Head is commentating at the star-studded event.]
I wonder how they compare.
Another odd one is old olive. I’ve had sections that when hit with an axe won’t split and bounce the axe. And seemingly remain unmarked. Splitting gnarled olive is miserable.