$fn = $preview ? 16 : 72;

module button_foot(height = 4, diameter = 18, hole_width = 5) {
button_offset = 1;
foot_length = diameter/2+16;
outside = 2;
foot_height = height+button_offset;
foot_width = 15;
hole_diameter = 3;
hole_clearance = hole_width;
hole_spacing = hole_clearance - hole_diameter;
rim_h = 1;
//bottom
  difference(){
    union(){
      cylinder(d=diameter+2*outside,h=foot_height);
      translate([-foot_width/2,0,0])
        cube([foot_width,foot_length,foot_height]);
    }
    //slot
    translate([-hole_clearance/2,-diameter,-1])
        cube([hole_clearance,diameter,foot_height+2]);
    //button insert
    translate([0,0,button_offset])
        cylinder(d=diameter,h=foot_height);
    //rim
    translate([-diameter/2-outside-2,-diameter,button_offset+rim_h])
        cube([diameter+2*outside+4,diameter,foot_height+2]);
    //wire slots
    hull(){
    translate([hole_spacing/2,0,-1])
        cylinder(d=hole_diameter*1.1,button_offset+2);
    translate([-hole_spacing/2,0,-1])
        cylinder(d=hole_diameter*1.1,button_offset+2);
    translate([0,hole_spacing/2,-1])
        cylinder(d=hole_diameter*1.1,button_offset+2);
        }

    // size indication
    translate([0,foot_length-1,foot_height]){
    linear_extrude(height=0.4,center = true) text(text=str(floor(diameter)),size=8,halign="center",valign="top");
    translate([0,-10,0])
    linear_extrude(height=0.4,center = true) text(text=str("mm"),size=5,halign="center",valign="top");
    }

  }
}