$fn=50;
translate([40,0,0]) union(){
cylinder (d=8, h=3);
cylinder (d=7.8, h=4.8);
}

translate([40,15,0]) union(){
cylinder (d=8, h=3);
cylinder (d=7.8, h=4.8);
}


translate([55,5,3])difference(){
cube([10.7, 14.8, 6], center = true);
translate([0,0,1])cube([9, 13, 5], center = true);}

translate([0,0,12.5])difference(){
cube([51.3, 47.7, 25], center = true);
translate([0,0,1])cube([54, 45.7, 25], center = true);}