Monitor Arm Extension

Short extension designed to adapt this monitor stand so that it holds a pair of 21.5" monitors exactly next to one another.
The extension is 60 mm long, 20 mm wide and 33 mm tall, with boltholes 9 mm in diameter. All these attributes are adjustable in the SCAD file if you need something custom.
$fn=80; length=60; width=20; height=33; boltDiameter=9; module boltHoles() { module boltHole() { translate([0,0,-(height+10)/2]) { cylinder(d=boltDiameter,h=height+10); } } translate([(length/2),0,0]) { boltHole(); } translate([-(length/2),0,0]) { boltHole(); } } module cornerRounder() { intersection() { cube([width,width,height], center=true); translate([width/2,0,-((height)/2)]) cylinder(d=width, h=height+10); } } difference() { union() { cube([length,width, height], center=true); translate([-((length/2)+width/2),0,0]) cornerRounder(); rotate([0,0,180]) translate([-((length/2)+width/2),0,0]) cornerRounder(); } boltHoles(); }