wolfhbot

pi= 3.14159265359;

module hole(diam, height, clearance= 0.1)
{
        fn= round(diam * pi / 0.5);
        cylinder(h= height, r=diam / 2 / cos(180 / fn) + clearance, $fn=fn);
}

module nutTrap(ffd, faces=6, height=1)
{
	cylinder(h= height, r=ffd / cos(180 / faces) / 2 + 0.05, $fn=faces);
}

// A slot which has rounded ends, but total length is l
module slot(d= 4, l= 8, ht= 1, clearance=0.1) {
	fn= round(d * pi / 0.5);
	rd= d / 2 / cos(180 / fn) + clearance;
	d1= rd*2;
	union() {
		translate([0,0,ht/2]) cube([l-d1, d1, ht], center=true);
		translate([-(l-d1)/2, 0, ht/2]) cylinder(h=ht, r=rd, $fn=fn, center=true); 
		translate([(l-d1)/2, 0, ht/2]) cylinder(h=ht, r=rd, $fn=fn, center=true); 
	}
	
}