openscad/project_box.scad

/* Project box

A parametric box for electronics projects using perforated circuit boards. The
board is held above the bottom of the box by four corner supports, and snaps
into place to hold it snugly while allowing easy removal.
*/

$fn=50;

board_x = 50;
board_y = 70;
board_thickness = 1; // [1:10]
clearance_above = 20; // [5:50]
clearance_below = 10; // [5:50]
fit_tolerance = 0.5;
corner_radius=3; // [1:10]
support_radius=5; // [1:10]
wall_width=3; // [3:10]

module _rounded_box(h, w, d, r) {
  hull() {
    translate([0 + r,0 + r,0])
      cylinder(h=h,r=r);
    translate([w - r,0 + r,0])
      cylinder(h=h, r=r);
    translate([w - r,d - r,0])
      cylinder(h=h, r=r);
    translate([0 + r,d - r,0])
      cylinder(h=h, r=r);
  }

}

module corner_post(h, r) {
  intersection() {
    translate([-0.001,-0.001,-0.001])
      cube([r*1.1, r*1.1, h*1.2]);
    cylinder(h=h, r=r);
  }
}

module project_box(x, y,
                   above=20,
                   below=10,
                   board_thickness=1,
                   fit_tolerance=0.5,
                   corner_radius=3,
                   support_radius=5,
                   wall_width=3) {
  height=board_thickness + above + below + (fit_tolerance * 2);
  width=board_x + (fit_tolerance * 2);
  depth=board_y + (fit_tolerance * 2);

  // container
  difference() {
    _rounded_box(h=height + (wall_width * 2),
                 w=width + (wall_width * 2),
                 d=depth + (wall_width * 2),
                 r=corner_radius);
    translate([wall_width,wall_width,wall_width])
      cube([width, depth, height + (wall_width * 2)]);
  }

  // supports
  translate([wall_width,wall_width,wall_width]) {
    translate([0,0,0])
      corner_post(h=below, r=support_radius);
    translate([width,0,0])
      rotate([0,0,90])
      corner_post(h=below, r=support_radius);
    translate([0,depth,0])
      rotate([0,0,270])
      corner_post(h=below, r=support_radius);
    translate([width,depth,0])
      rotate([0,0,180])
      corner_post(h=below, r=support_radius);
  }


  // locking nubs
  translate([wall_width,wall_width,wall_width]) {
    nub_size = 1;
    nub_width = board_y / 4;
    nub_height = below + board_thickness + (nub_size/2) + (fit_tolerance*2);
    translate([0,board_y / 2 - nub_width / 2,nub_height])
      rotate([270,0,0])
      cylinder(h=nub_width, r=1);
    translate([width,board_y / 2 - nub_width / 2,nub_height])
      rotate([270,0,0])
      cylinder(h=nub_width, r=1);
  }
}

project_box(board_x, board_y,
            above=clearance_above,
            below=clearance_below,
            board_thickness=board_thickness,
            fit_tolerance=fit_tolerance,
            corner_radius=corner_radius,
            support_radius=support_radius,
            wall_width=wall_width);