// 19 to 22 inch rack adapter

// Change these to adjust the total adapter size
full_length = 80;
full_width = 44.23;
full_height = 45;

// Change these to adjust the interface to your device
support_bracket_thickness = 10;
support_bracket_base_thickness = 2.5;
support_bracket_hole_y_offset = 18;
support_bracket_hole_z_offset = 18;
support_bracket_hole_r = 2;

// Change these to adjust the interface to your rack (should be standard)
rack_mount_length = 20;
rack_mount_thickness = 2.5;
rack_mount_hole_r = 6.5 / 2;
rack_mount_hole_x_offset = (11.75 / 2) + 5.3;
rack_mount_hole_y_offset = rack_mount_hole_r + 2.9;

// Add two triangle supports that end at the start of the interface to the rack.
module dual_supports(length, width, height, support_length, support_thickness, support_base_thickness) {
  difference() { // Extra triangle supports on both sides of the Y axis
    translate([support_base_thickness, 0, 0])
      linear_extrude(height(x, y) = (-width / support_length) * x + width) square(size = [support_length, width]);
    translate([support_base_thickness, support_thickness, 0])
      linear_extrude(height) square(size = [support_length, width - support_thickness * 2]);
  }
}

// Create our basic L-shaped bracket
module l_bracket(length, width, height, rack_thickness, support_base_thickness) {
  difference() { // Cut our L bracket
    linear_extrude(height) square(size = [length, width]);

    translate([0,0, rack_thickness])
      linear_extrude(height)
      translate([support_base_thickness, 0]) square(size = [length, width]);
  }
}

// Cuts the bolt holes for attachingto the rack
module rack_bolt_holes(height, x_offset, y_offset, rack_hole_r) {
  // Holes for rackmount
  translate([x_offset, y_offset, 0])
    linear_extrude(height) circle(r = rack_hole_r);
}

module support_screw_hole(height, y_offset, z_offset, support_hole_r) {
  translate([-1, y_offset, z_offset]) rotate(a = [0, 90])
    linear_extrude(height) circle(r = support_hole_r);
}

// Builds the full object
module rack_adapter(length, width, height, rack_length, rack_thickness, rack_hole_r, rack_hole_x_offset, rack_hole_y_offset, support_thickness, support_base_thickness, support_hole_y_offset, support_hole_z_offset, support_hole_r) {

  support_length = length - rack_length;

  difference() { // For adding the screw holes

    union(r = 0) { // Combine supports with L bracket
      dual_supports(length, width, height, support_length, support_thickness, support_base_thickness);
      l_bracket(length, width, height, rack_thickness, support_base_thickness);
    }

    // Holes for rackmount
    rack_bolt_holes(height, rack_hole_x_offset + support_length, width - rack_hole_y_offset, rack_hole_r);
    rack_bolt_holes(height, rack_hole_x_offset + support_length, rack_hole_y_offset, rack_hole_r);

    // Holes for mounting to unit

    support_screw_hole(height, support_hole_y_offset, support_hole_z_offset, support_hole_r);
    support_screw_hole(height, width - support_hole_y_offset, support_hole_z_offset, support_hole_r);
    support_screw_hole(height, support_hole_y_offset, height - support_hole_z_offset, support_hole_r);
    support_screw_hole(height, width - support_hole_y_offset, height - support_hole_z_offset, support_hole_r);
  }
}

// Call the main construct
rack_adapter(full_length, full_width, full_height, rack_mount_length, rack_mount_thickness, rack_mount_hole_r, rack_mount_hole_x_offset, rack_mount_hole_y_offset, support_bracket_thickness, support_bracket_base_thickness, support_bracket_hole_y_offset, support_bracket_hole_z_offset, support_bracket_hole_r);