//parameters
// sizes are in mm

edges = 6;
diameter = 60;
thickness = 3;
clearance = 0.127;
slotLength = 20;
kerf = 0.255;

// code

$fn = edges;

buildObject();

module buildObject() {
difference() {
circle(d=diameter);
    for (p = [0:edges-1]) {
		rotate([0,0,p*360/edges]) {
    translate([0,(diameter/2)-slotLength,0])
        square([thickness+clearance-kerf, slotLength]);
        }
}};
};