board_x = 5;
board_y = 5;
board_z = 0;

board_length = 1000;
board_width = 1000;
board_height = 12;

board_wall_length = 160;
board_wall_width = 1000;
board_wall_height = 12;

board_wall_j_width = 6;
board_wall_j_length = 6;
board_wall_j_height = 12;

wall_j_width = 6;
wall_j_length = 6;
wall_j_height = 12;

wall_height = 60;

cell_size = board_length/10;// it's equal to car width/length(will be fine if car be quadrat)

module board(x, y, z, length, width, height) {
    translate([x, y, z]) 
        color("orange") 
        cube([length , width, height]);
}

module set_board_nets(x, y, z, length, width, height) {
    for(i = [board_x + cell_size : cell_size/2 : (board_length)]) {
        for(j = [board_y + cell_size : cell_size/2 : board_width]){
                translate([i, j, 0])
                    color("red")
                    cube([length, width, height]);
        }
    }
}

module BoardWithNets() {
    difference() {
        board(board_x, board_y, board_z, board_wall_length, board_width, board_height);
        set_board_nets(board_x, board_y, board_z+2, wall_j_width, wall_j_length, wall_j_height);
    }
}

module joint(tx, ty) {
    translate([tx, ty, 0]) color("black") cube([board_height - 0.3, board_height * 8, board_height]);
}

projection(cut = false) {
    
    union() {
        // Main board with side slots cut out
        difference() {
            board(board_x, board_y, board_z, board_wall_length, board_width, board_height);
            for (pos = [1/5, 2/5, 3/5, 4/5]) {
                offset = board_length * pos - board_height * 4;
                joint(board_x + board_wall_length/2 - board_height, board_y + offset);
            }
        }

        // Add the top and bottom joints (tabs) 
        for (y_pos = [board_y - board_wall_height, board_y + board_width]) {
            for (pos = [1/3, 2/3]) {
                //offset = board_wall_length * pos - board_height*2 + board_height/2;
                offset = board_wall_length * pos - board_height*2 + board_height/2;
                translate([board_x + offset, y_pos, 0]) 
                    color("black") 
                    cube([board_height * 2.5, board_height, board_height]);
            }
        }
    }
    
}