Comments by "David Elliott" (@davidelliott5843) on "Machine Thinking" channel.

  1.  @a0flj0  Not really. Most static planers cannot produce a flat board. The simply make a smooth sided board with the same old bends. To flatten a board you have to get one side flat. That's a considerable skill as every raw slab is different.
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  2. Multi stage series water pumps have all impellers at the same size. Water is not compressible but pressure is increased at each stage.
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  3. Tesla has recently got back to structural castings with their precision mega casting (pressure die cast) machines.
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  4. Before 1800 the only power we had was people (slaves) and animals. The industrial lathe allowed steam to be used for power. But coal was labour intensive so people only really benefitted when oil became the main power source. in the late C19th.
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  5. It’s no coincidence that human slavery was abolished around the mid C19th. Precision machines like theses allowed us to make coal and oil our slaves.
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  6. The screw/bolt issue is clouded by the "set screw". These are generally considered to be fasteners with the threads going up the whole way. There is no shank. They are more likely to have a socket head or screwdriver slotted head but it can be square or hex-headed. Bolts have thread going part way up the shank. This creates a stronger fastener. The easiest distinction is full thread = set screw. Part thread = bolt. Wikipedia confuses the issue by confusing the set screw with the "grub screw". The latter is fully threaded but has no head. The driving end is slotted or socketed so the screw can be turned and driven below the surface. These are used to lock items together e.g. fixing a wheel to a shaft. Grub screws and Set Screws are not the same.
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