//------------------------------------------------------------
// Parametric pendulum rod coupling to increase frame stiffness
//
// http://www.thingiverse.com/wardwouts
//
// You'll need four of these to connect two bars and an appropriate
// M3 screw and nut
//------------------------------------------------------------

// This needs to be tight, so about 5.8-ish for M6; 7.8-ish for M8
M6 = 5.8;

// And this can have some play
M3 = 3.5;

// Thickness at its weakest point
thickness = 3;

// Distance between the two holes
seperation = 1.5;

// Diameter of the disc
diameter = 30;

//80 for nice cylinders; 16 for speed
FN=80*1;

height = M6/2 + thickness;

echo(str("========================================"));
echo(str("The combined height will be ", height*4, " mm"));
echo(str("So use a screw of at least ", round(height*4 +5), " mm length"));
echo(str("========================================"));

module base(){
	difference(){
		cylinder(h=height, r=diameter/2, $fn=FN);
		union(){
			translate([0,0,-height/2]){
				cylinder(h=height*2, r=M3/2, $fn=FN);
			}
			translate([-diameter/2,M3/2+M6/2+seperation,height]){
				rotate([0,90,0]){
					cylinder(h=diameter*2, r=M6/2, $fn=FN);
				}
			}
		}
	}
}

base();
