OpenSCAD Source Code: Olfa Rotary Cutter Spacer Washer

Olfa Rotary Cutter.scad

// Olfa rotary cutter backing washer
// Ed Nisley KE4ZNU January 2016

Layout = "Build";

//- Extrusion parameters must match reality!
//  Print with +1 shells and 3 solid layers

ThreadThick = 0.20;
ThreadWidth = 0.40;

HoleWindage = 0.2;

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

Protrusion = 0.1;           // make holes end cleanly

//----------------------
// Dimensions

WasherOD = 35.0;
WasherThick = 1.5;

WaveOD = 14.0;												// wave washer flat dia
WaveM = 1.8;												// height of wave washer bend
BendRad = (pow(WaveM,2) + pow(WaveOD,2)/4) / (2*WaveM);		// radius of wave washer bend

echo(str("Wave washer bend radius: ",BendRad));

SpacerID = WaveOD + 2.0;
SpacerThick = 2*ThreadThick;

NumSides = 12*4;
$fn = NumSides;
//----------------------
// 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(r=(FixDia + HoleWindage)/2,
         h=Height,
         $fn=Sides);
}

//----------------------
// Parts

module Upper() {
	difference() {
		cylinder(d1=WasherOD,d2=(WasherOD - 2.0),h=WasherThick);
		translate([0,0,-Protrusion])
			intersection() {
				PolyCyl(8.2,2.0,8);
				cube([(6.0 + HoleWindage),10,2*WasherThick],center=true);
			}
		translate([-(WaveOD + 1.0)/2,0,BendRad])
			rotate([0,90,0]) rotate(0*180/16)
				PolyCyl(BendRad*2,(WaveOD + 1),16);
	}
}

module Spacer() {
	difference() {
		cylinder(d=WasherOD,h=SpacerThick);
		translate([0,0,-Protrusion])
			cylinder(d=SpacerID,h=2*SpacerThick);
	}	
}

//----------------------
// Build it!

if (Layout == "Show") {
	translate([0,0,SpacerThick])
		color("Cyan")
			Upper();
	color("LightCyan")
		Spacer();
}

if (Layout == "Build") {
	translate([-0.6*WasherOD,0,0])
		Upper();
	translate([0.6*WasherOD,0,0])
		Spacer();
}

More details on my blog at http://wp.me/poZKh-5xG