Re: cordless tool 18V to 12V converter

"David Billington"  wrote in message news:ut5l7s$3aes8$1@dont-email.me...
On 17/03/2024 00:23, Jim Wilkins wrote:

"David Billington"  wrote in message news:ut5b5o$352d4$1@dont-email.me...
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On 16/03/2024 23:36, Jim Wilkins wrote:

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"Jim Wilkins"  wrote in message news:ut5195$334ch$1@dont-email.me...
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"Jim Wilkins"  wrote in message news:ut4jh5$309ec$1@dont-email.me...
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I doubled it to 200 Lbs, one tick mark,  on a 3/8" thick square of red oak
in a plastic bag and added water about 20 minutes ago. So far the gauge
needle hasn't moved.
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4 hours later, if anything the pressure has decreased by the pointer width.
Into the freezer with it, until I need the space for the kettle of beef stew
I'm cooking.
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2 more hours, 0F, the pressure is zero and the C clamp isn't tight. Out to see if the pressure recovers as the gauge warms.
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It does, a little.
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Either wet wedging doesn't work or I missed something.

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Why I asked about the type of oak is that I was told red oak has an open
cell structure and can allow water to wick into the wood easily which
isn't the case with other types of oak, maybe in this case that is
preventing any cellular swelling or allowing any pressure to squeeze the
water out. Can you repeat the test with white oak. I have some English
oak here but my force gauge is out of action until I replace the
loadcell lead.
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My white oak is still in logs so sample prep could take a while and this is a busy time of year, I need to split and stack next year's firewood to dry, upgrade a few things on the sawmill and get the logs out of my front yard. I paused outdoor projects in mid December and began again in February. The question is academic if steel wedges and feathers are available.
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The gauge has warmed up and the pressure recovered, so maybe the gauge oil shrank?
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More on splitting stone:
https://www.dartmoorcam.co.uk/CAM/SplittingGranite.htm
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Did you read that page as they mention the process I mentioned and you
were trying to test.
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Of course, that's why I posted it. I was looking for more detail like species of wood or hands-on experience, which are usually missing from accounts of ancient technology, even Heron, Vitruvius and Frontinus. Until the incomplete Greek temple at Didyma was examined scholars had only guessed at Greek construction methods. The rough walls of the temple foundation revealed the geometric layout inscribed full-size on them, to be erased and lost when the walls were polished. The subtle convex curvature of straight lines that counters the eye's tendency to distort had been laid out as a short arc and then the offsets transferred to the full size layout of the stone work, like copying a wooden ship's hull frames from the half model.
https://www.designingbuildings.co.uk/wiki/Entasis
Hands-on technique wasn't recorded until the medieval and renaissance books by Theophilius, Biringuccio, Agricola and Cellini. Before printing literacy was very unusual, the first Wilkins in the Roanoke Colony, in 1619, became a plantation owner, judge and member of the House of Burgesses yet couldn't write his own name.
Supposedly tree roots can split boulders. I pulled a live root out of a crack and squeezed it with pliers, and found that it was soft and easily compressed.
MatWeb gives the tensile strength of granite as 7-25MPa, 1-3.6ksi. My wet oak sample crushes at 400 Lbs from the 0.52" diameter C clamp pad, about 1.9ksi. Maybe it could force apart its own area of granite. Steel wedges placed and used as directed don't split it easily, the advice is to tap them all in to the same high pitched Tink and wait.
I suspect that bronze or iron wedges were always used, and wooden ones have the same validity as needing the urine of a red-headed boy for quenching steel. Sacrificial wood shims might have served to reduce the high friction and damage I found with soft iron wedges rubbing on rough rock. A visitor seeing them after the valuable iron wedges had been removed could have guessed or been told a tradesmans' idiot-test joke like that the nails in a box that point away from the wall being built are for the other side.
This experiment showed that my 10,000 Lb hydraulic load cell isn't right for the this task. One tick mark is 200 Lbs. For critical work it's recommended to make measurements at around half scale or more.