My_Heart_Threads

// response to openscad screw threads with linear_extrude by speedymollusc
// For OpenScad coders.

// A slice through a bolt has the shape of a shallow heart.
// If we look at it radially from zero to 180 degrees,
// it increases linearly from the minor to the major radius.
// At zero degrees it will have the radius of the minor radius of the threads
// at 90 degrees it will be at the pitch radius
// then at 180 degrees it will be at the major radius.
// It's the