BallChain Gear parametric OpenSCAD

Hey there,

this is a parametric ballchain gear for a shaft with flatspot.
Feel free for non-commercial use.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Following Parameter can be changed:
//Shaft Settings
dShaft = 4;
depthFlatShaft = 3.5;
height = 7;

//BallChain Settings
dBall = 2.7;
wRope = 0.55;
nBalls = 10;
distanceBallToBall = 3.4;

//Calc Outer Diameter of Gear
dOuter = nBalls * distanceBallToBall / 3.141592653589793;

// Global resolution
$fs = 0.1; // Don't generate smaller facets than 0.1 mm
$fa = 3; // Don't generate larger angles than 5 degrees