WizardOfBoz
Diamond
- Joined
- Sep 30, 2006
- Location
- SE PA, Philly
Certain fundamental constants of nature and mathematics are set to mesh with reality: pi is the ration of circle circumference to diameter, and e works out to be geometrically set as well*.
Other numbers are set by man. An inch used to be a skosh over 2.54cm, now it's defined to be exactly 2.54cm.
Still other numbers are set to optimize the physics of a situation. 60degree centers give you optimal lateral stiffness, with less friction.
But because drills come in 118 degree, and 135 degree configurations commonly (and others, less commonly), I wonder who/what determined those angles. Also, why do the Starrett and General drill gauges only have the 59 degree half-angle?
Perhaps this is a no-brainer, but no obvious reason came to me.
Thanks,
Jim
*e is the unique real number such that the value of the derivative (slope of the tangent line) of the function f(x) = e^x at the point x = 0 is exactly 1.
Other numbers are set by man. An inch used to be a skosh over 2.54cm, now it's defined to be exactly 2.54cm.
Still other numbers are set to optimize the physics of a situation. 60degree centers give you optimal lateral stiffness, with less friction.
But because drills come in 118 degree, and 135 degree configurations commonly (and others, less commonly), I wonder who/what determined those angles. Also, why do the Starrett and General drill gauges only have the 59 degree half-angle?
Perhaps this is a no-brainer, but no obvious reason came to me.
Thanks,
Jim
*e is the unique real number such that the value of the derivative (slope of the tangent line) of the function f(x) = e^x at the point x = 0 is exactly 1.