/* GNU AGPLv3 (or later at your option)
   see bottom for more license info */

/* protective housing for crazyflie 2.0.

   reinforce the arms so they do not snap.

   keep the props up high so they do not get hairs from the ground
   wrapped around the motor shaft.
 */

$fn = 300;

// propeller diameter was measured with calipers
propeller_radius = 46.35 / 2;
// 7mm from spec
motor_grippable_height = 8;
motor_gripper_height = motor_grippable_height / 2;
holder_height = motor_grippable_height * 1.1;

propeller_radius_measured = 46.35 / 2;
holder_wall_thickness = 1.2;
propeller_guard_wall_thickness = 1.2;

motor_diameter = 7;
motor_height_measured = 17;
motor_radius = motor_diameter / 2;

module propeller_protector(motor_radius,
                           holder_wall_thickness,
                           propeller_guard_wall_thickness,
                           motor_gripper_height,
                           holder_height,
                           propeller_radius) {
  propeller_guard_inner_radius = propeller_radius + 1.5;
  holder_outer_radius = motor_radius + holder_wall_thickness;
  number_of_arms = 3;
  linear_extrude(height = motor_gripper_height) {
    // part that holds the motor
    difference() {
      circle(r = holder_outer_radius);
      circle(r = motor_radius); }
    for(arm_number = [0: (number_of_arms - 1)]) {
      rotate(arm_number * (360 / number_of_arms)) {
        translate([-propeller_guard_inner_radius,
                   -holder_wall_thickness / 2]) {
          square([propeller_guard_inner_radius - motor_radius,
                  holder_wall_thickness]); } } } }
  // prop protector
  linear_extrude(height = holder_height) {
    difference() {
      circle(propeller_guard_inner_radius +
             propeller_guard_wall_thickness);
      circle(propeller_guard_inner_radius); } } }

propeller_protector(motor_radius,
                    holder_wall_thickness,
                    propeller_guard_wall_thickness,
                    motor_gripper_height,
                    holder_height,
                    propeller_radius_measured);

/*
  This file is part of 3d-printables.

  3d-printables is free software: you can redistribute it and/or modify
  it under the terms of the GNU Affero General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  3d-printables is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU Affero General Public License for more details.

  You should have received a copy of the GNU Affero General Public License
  along with challenge-bot.  If not, see <http://www.gnu.org/licenses/>.
*/