OpenSCAD source code: plastic parts for garden cart handle attachment

Garden Cart Handle.scad

// Garden Cart Handle Pivot
// Ed Nisley KE4ZNU 2022-05

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

/* [Hidden] */

ThreadThick = 0.25;
ThreadWidth = 0.40;

HoleWindage = 0.2;

Protrusion = 0.1;     // make holes end cleanly

inch = 25.4;

function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit);

ID = 0;
OD = 1;
LENGTH = 2;


//----------
// Dimensions
// Handle lies along X axis

HandleOD = (7/8) * inch;

BoltOD = (5/16) * inch;

Washer = [BoltOD,1.0 * inch,2.0];     // just for Show

Disk = [BoltOD,62.0,(3/16) * inch];

ClampBase = [(1 + 7/8)*inch,(1 + 1/8)*inch,2.0];

Kerf = 2.0;

CornerRadius = 1.0;

PivotOA = [Disk[OD],Disk[OD],HandleOD + 2*ClampBase.z + 2*Disk[LENGTH]];

//----------------------
// Useful routines

module PolyCyl(Dia,Height,ForceSides=0) {     // based on nophead's polyholes
  Sides = (ForceSides != 0) ? ForceSides : (ceil(Dia) + 2);
  FixDia = Dia / cos(180/Sides);
  cylinder(d=(FixDia + HoleWindage),h=Height,$fn=Sides);
}

//----------------------
// Set up parts

module Handle() {
  translate([-2*PivotOA.x,0,0])
    rotate([0,90,0])
      PolyCyl(HandleOD,4*PivotOA.x,24);
}

module Bolt() {
   translate([0,0,-PivotOA.z])
      PolyCyl(BoltOD,2*PivotOA.z,12);
}

module Pivot() {
  difference() {
    union() {
      hull()
        for (i=[-1,1], j=[-1,1])                                // rounded block
          translate([i*(ClampBase.x/2 - CornerRadius),j*(ClampBase.y/2 - CornerRadius),-PivotOA.z/2])
            cylinder(r=CornerRadius,h=PivotOA.z,$fn=4*8);
      for (k=[-1,1])
        translate([0,0,k*(PivotOA.z/2 - Disk[LENGTH]/2)])
          rotate(180/36)
            cylinder(d=Disk[OD],h=Disk[LENGTH],$fn=36,center=true);
    }

    Handle();
    Bolt();
    cube([2*ClampBase.x,2*ClampBase.y,Kerf],center=true);     // slice through center
  }
}





//----------
// Build them

if (Layout == "Show") {
  rotate([90,-45,0]) {
    Pivot();
    color("Green")
      translate([2*PivotOA.x - PivotOA.x/2,0,0])
        Handle();
    color("Red")
      Bolt();
    color("Yellow")
      for (k=[-1,1])
        translate([0,0,k*(PivotOA.z/2 + Washer[LENGTH])])
          rotate(180/36)
            cylinder(d=Washer[OD],h=Washer[LENGTH],$fn=36,center=true);
  }
}

if (Layout == "Build") {
  Offset = 5.0;
  intersection() {
    translate([-(PivotOA.x/2 + Offset),0,PivotOA.z/2])
      Pivot();
    translate([-2*PivotOA.x,-2*PivotOA.y,0])
      cube([4*PivotOA.x,4*PivotOA.y,PivotOA.z/2],center=false);
  }
  intersection() {
    translate([(PivotOA.x/2 + Offset),0,PivotOA.z/2])
      rotate([180,0,0])
        Pivot();
    translate([-2*PivotOA.x,-2*PivotOA.y,0])
      cube([4*PivotOA.x,4*PivotOA.y,PivotOA.z/2],center=false);
  }
}

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