$fn=200;
diameter=50;
width=10;
height=10;

difference(){
    cylinder(d=(diameter+width),h=height);
    translate([0,0,-1])
        cylinder(d=diameter,h=(height+2));
}
translate([cos(30)*(diameter+(width/2)),sin(30)*(diameter+(width/2)),0])
    difference(){
        cylinder(d=(diameter+width),h=height);
    translate([0,0,-1])
        cylinder(d=diameter,h=(height+2));
    }
translate([cos(30)*(diameter+(width/2)),-sin(30)*(diameter+(width/2)),0])
    difference(){
        cylinder(d=(diameter+width),h=height);
    translate([0,0,-1])
        cylinder(d=diameter,h=(height+2));
    }