Recent content by jixon

Focal length 79.2", 0.256 in. @ apex; f/4.4 Using a CNC lathe but need inputs for autocad program to 'run' lathe for accurate cutting. Removing 32.53 cu. in. material. Not sure what to plot for points along 'x' to perimeter from center, depth of 'y'

Not to worry; the super volcano under Yellowstone will blow, removing the need to worry about compasses not working or excess RADiation from the Sun.

Parabola for 18" aluminum mirror Help; need to configure inputs into parabola formula to machine an 18" dia., 1.5"h aluminum disc. for use as primary objective mirror in telescope.