$fn = 64;

// --- Parameters ---
station_width = 160;
station_depth = 45;
station_height = 110;
wall_thickness = 8;
tube_diameter = 23; // Sized to fit standard 20mm to 22mm glass test tubes
num_tubes = 3;
tube_spacing = 45;

module propagation_station() {
    union() {
        // Extended base footprint for added stability
        translate([0, 0, wall_thickness/4])
            cube([station_width + 15, station_depth + 15, wall_thickness/2], center=true);
            
        difference() {
            // Main rectangular frame
            translate([0, 0, station_height/2])
                cube([station_width, station_depth, station_height], center=true);
            
            // Inner frame cutout (creates the open front and back)
            translate([0, 0, station_height/2])
                cube([
                    station_width - wall_thickness * 2, 
                    station_depth + 2, 
                    station_height - wall_thickness * 2
                ], center=true);
            
            // Tube holes and resting recesses
            for (i = [0 : num_tubes - 1]) {
                x_pos = (i - (num_tubes - 1) / 2) * tube_spacing;
                
                // Top holes (pass-through for inserting tubes)
                translate([x_pos, 0, station_height - wall_thickness - 1])
                    cylinder(h=wall_thickness + 2, d=tube_diameter);
                
                // Bottom recesses (half-depth cuts to hold the base of the tubes)
                translate([x_pos, 0, wall_thickness/2])
                    cylinder(h=wall_thickness, d=tube_diameter);
            }
        }
    }
}

// Render the model
propagation_station();