holes_plate.scad

$fn = 24;

size = [170, 150];
interval = 5;

linear_extrude(3)
difference() {
    translate(size / 2)
    offset(r=interval)
    square(size - [1, 1] * interval * 2, center=true);
        
    for (x=[interval : interval : size[0] - interval])
    for (y=[interval : interval : size[1] - interval])
    translate([x, y])
    circle(d=3.6);
}