| 1 | // challenge-bot |
| 2 | // GNU AGPLv3 (or later at your option) |
| 3 | // project available at these locations: |
| 4 | // https://gitorious.org/ozzloy/challenge-bot |
| 5 | // https://github.com/waynegramlich/challenge-bot |
| 6 | |
| 7 | wheel_depth = 6; |
| 8 | wheel_radius = 68/2; |
| 9 | |
| 10 | module encoder_shaft(){ |
| 11 | // measured with calipers, checked against the motor shaft |
| 12 | motor_shaft_big = 3.7; |
| 13 | motor_shaft_small = 4.8; |
| 14 | motor_shaft_length = wheel_depth * 3 / 4; |
| 15 | |
| 16 | intersection(){ |
| 17 | cylinder(h = motor_shaft_length, |
| 18 | r = motor_shaft_big, |
| 19 | center = true, |
| 20 | $fn = 30); |
| 21 | // x direction is multiplied by 2 because the radius of the cylinder |
| 22 | // goes in both directions. the extra .1 is for overlap |
| 23 | cube([motor_shaft_big * 2.1, motor_shaft_small, motor_shaft_length], |
| 24 | center = true);}} |
| 25 | |
| 26 | module mounting_screw(){ |
| 27 | cylinder(h = wheel_depth * 1.1, r = 1, $fn = 30, center = true);} |
| 28 | |
| 29 | module wheel(){ |
| 30 | translate([0, 0, wheel_depth / 2]){ |
| 31 | difference(){ |
| 32 | cylinder(h = wheel_depth, r = wheel_radius, center = true, $fn = 30); |
| 33 | translate([0, 0, wheel_depth / 4]){ |
| 34 | scale([1, 1, 1.1]){ |
| 35 | encoder_shaft();}} |
| 36 | mounting_screw(); |
| 37 | for(i = [1 : 5]){ |
| 38 | rotate(i * 360/5, [0, 0, 1]){ |
| 39 | translate([0, 0, -0.6 * wheel_depth]) |
| 40 | between_spokes();}} |
| 41 | translate([0, 0, wheel_depth / 4]){ |
| 42 | difference(){ |
| 43 | cylinder(h = wheel_depth / 1.2, |
| 44 | r = 0.85 * wheel_radius, |
| 45 | center = true); |
| 46 | cylinder(h = wheel_depth / 1.2, |
| 47 | r = 0.23 * wheel_radius, |
| 48 | center = true);}}}}} |
| 49 | |
| 50 | module wheel_block(){ |
| 51 | cube([wheel_radius, wheel_radius, wheel_depth]);} |
| 52 | |
| 53 | module pie_slice(){ |
| 54 | intersection(){ |
| 55 | translate([0, 0, wheel_depth / 2]){ |
| 56 | cylinder(h = wheel_depth, |
| 57 | r = 0.85 * wheel_radius, |
| 58 | center = true);} |
| 59 | translate([0, wheel_radius * 0.3, 0]){ |
| 60 | rotate([0, 0, (360 / 5) / 2]){ |
| 61 | intersection(){ |
| 62 | wheel_block(); |
| 63 | rotate([0, 0, 90 - 360 / 5]) |
| 64 | wheel_block();}}}}} |
| 65 | |
| 66 | module between_spokes(){ |
| 67 | minkowski(){ |
| 68 | pie_slice(); |
| 69 | cylinder(h = wheel_depth / 2, r = 1, $fn = 30);}} |
| 70 | |
| 71 | wheel(); |