OpenSCAD source code: single-layer cover for seam ripper

Seam Ripper Cover.scad

// Cover for old seam ripper
// Ed Nisley  - KE4ZNU
// 2019-03

/* [Layout Options] */

Layout = "Build";          // [Show,Build]

Part = "Handle";          // [Handle,CoverSolid,Cover]

/* [Extrusion Parameters] */

ThreadWidth = 0.40;
ThreadThick = 0.25;

HoleWindage = 0.2;

Protrusion = 0.1;

//-----
// Dimensions


/* [Dimensions] */

WallThick = 1*ThreadWidth;

CapInsideLength = 48.0;

CornerRadius = 2.0;                 // handle at base

Base = [11.0,5.5,0.0];              // handle at base

Tip = [8.2,3.7,CapInsideLength];    // inferred at tip

HandleOC = [Base - 2*[CornerRadius,CornerRadius,0.0],
            Tip - 2*[CornerRadius,CornerRadius,CornerRadius/2]
           ];

NumSides = 2*3*4;


//-----
// Useful pieces

// Handle is basically the interior of the cover

module Handle() {

  intersection() {
    hull()
      for (i=[-1,1], j=[-1,1], k=[0,1])
        translate([i*HandleOC[k].x/2,j*HandleOC[k].y/2,k*HandleOC[k].z])
          sphere(r=CornerRadius,$fn=NumSides);
    translate([0,0,-CornerRadius/2])          // chop tip for better bridging
      rotate([45,0,0])
        cube([2*Base.x,CapInsideLength*sqrt(2),CapInsideLength*sqrt(2)],center=true);
  }
}

module CoverSolid() {

  hull()
    for (i=[-1,1], j=[-1,1], k=[0,1])
      translate([i*HandleOC[k].x/2,j*HandleOC[k].y/2,k*HandleOC[k].z])
        sphere(r=CornerRadius + WallThick,$fn=NumSides);

}

module Cover() {

  difference() {
    CoverSolid();
    Handle();
    translate([0,0,-CornerRadius])
      cube(2*Base + [0,0,2*CornerRadius],center=true);
  }
}

//-----
// Build things

if (Layout == "Build") {
  Cover();
}

if (Layout == "Show")
  if (Part == "Handle")
    Handle();
  else if (Part == "CoverSolid")
    CoverSolid();
  else if (Part == "Cover")
    Cover();

More details on my blog at https://wp.me/poZKh-89m