The New Hotness

For reasons not relevant here, I was tapped to replace the plastic parts attaching the handle to a garden cart:

Garden Cart - handle attachment — Garden Cart – handle attachment

The owner tried to contact the “manufacturer” to no avail; repair parts are simply not available, even if the name painted on the cart had a meaningful relationship to anything else.

Well, I can fix that:

Garden Cart - handle repair parts — Garden Cart – handle repair parts

Fortunately, another cart in the fleet provided the missing bits so I could reverse-engineer their measurements.

The solid model looks about like you’d expect:

Garden Cart Handle - show view — Garden Cart Handle – show view

Printing the two halves with those nice (yellow) bosses in place wasn’t feasible. They were exactly 1 inch in diameter, so I just parted two cookies from the end of a stout acetal rod after drilling a hole for the 2-¼ inch 5/16-18 bolt.

The two pieces took nigh onto three hours with five perimeters and 50% infill:

Garden Cart Handle - slicer preview — Garden Cart Handle – slicer preview

While delivering and installing the parts, I got volunteered to haul plants to cars with one of the carts during the upcoming Spring Plant Sale. That’ll teach me to stay in the Basement Shop …

The OpenSCAD source code as a GitHub Gist:

	// 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 + 2ClampBase.z + 2Disk[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([2ClampBase.x,2ClampBase.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([-2PivotOA.x,-2PivotOA.y,0])
	cube([4PivotOA.x,4PivotOA.y,PivotOA.z/2],center=false);
	}
	intersection() {
	translate([(PivotOA.x/2 + Offset),0,PivotOA.z/2])
	rotate([180,0,0])
	Pivot();
	translate([-2PivotOA.x,-2PivotOA.y,0])
	cube([4PivotOA.x,4PivotOA.y,PivotOA.z/2],center=false);
	}
	}

view raw Garden Cart Handle.scad hosted with ❤ by GitHub

The New Hotness

Garden Cart Handle Pivot