OpenSCAD source code: Flashlight mount ball clamp

Fairing Flashlight Mount.scad: Flashlight ball clamp excerpt

//- Clamp around flashlight ball

module BallClamp() {

  BossLength = ClampScrew[LENGTH] - ClampScrewNut[LENGTH] - 2*ClampScrewWasher[LENGTH] - 4*ThreadThick;

  difference() {
    union() {
      intersection() {
        sphere(d=ClampOD,$fn=NumSides);                       // exterior ball blamp
        cube([ClampLength,2*ClampOD,2*ClampOD],center=true);  // aiming allowance
      }
      for (i=[0])
        hull() {
          for (j=[-1,1])
            translate([i*(ClampLength/2 - ClampScrew[OD]),j*ClampScrewOC/2,-BossLength/2])
              rotate(180/8)
                cylinder(d=(ClampScrewWasher[OD] + 2*ThreadWidth),h=BossLength,$fn=8);
        }
    }

    sphere(d=(BallOD + 1*ThreadThick),$fn=NumSides);        // interior ball

    for (i=[0] , j=[-1,1]) {
        translate([i*(ClampLength/2 - ClampScrew[OD]),j*ClampScrewOC/2,-ClampOD])   // screw clearance
          rotate(180/8)
            PolyCyl(ClampScrew[ID],2*ClampOD,8);
    }

  }


  color("Yellow")
  if (Support) {                                                  // ad-hoc supports for top half
    NumRibs = 6;
    RibLength = 0.5 * BallOD;
    RibWidth = 1.9*ThreadWidth;
    SupportOC = ClampLength / NumRibs;

    cube([ClampLength,RibLength,4*ThreadThick],center=true);     // base plate for adhesion

    intersection() {
      sphere(d=BallOD - 0*ThreadWidth);                         // cut at inner sphere OD
      cube([ClampLength + 2*ThreadWidth,RibLength,BallOD],center=true);
      union() {                                                 // ribs for E-Z build
        for (j=[-1,0,1])
          translate([0,j*SupportOC,0])
            cube([ClampLength,RibWidth,1.0*BallOD],center=true);
        for (i=[0:NumRibs])       // allow +1 to fill the far end
          translate([i*SupportOC - ClampLength/2,0,0])
            rotate([0,90,0])
              cylinder(d=BallOD - 2*ThreadThick,
                      h=RibWidth,$fn=NumSides,center=true);
      }
    }
  }
}

More details on my blog at http://wp.me/poZKh-6Vc