// https://gitorious.org/ozzloy/challenge-bot
// https://github.com/waynegramlich/challenge-bot
+/*
+ this holds an hc-sr04 sonar sensor to a 3/16 inch deck.
+ http://fritzing.org/projects/hc-sr04-project
+ it can hold the sonar sensor either facing down, or forwards.
+ when facing down, it can detect if it passes over the edge of a table.
+ when facing forwards, it can detect and follow something in front of it.
+ */
+
$fn = 60;
+use <oshw.scad>
+oshw_dy = 120.366;
+oshw_dx = 133.888;
+
// 3/16 inch in mm deck_depth = 4.7625;
-// 1/4 inch in mm - a little to be a squeeze fit
-deck_depth = 6.35 - 0.4;
-sonar_plate_width = 20;
+// 1/4 inch in mm = 6.35
+// subtract a little to be a squeeze fit
+deck_depth = 4.7625 - 0.4;
// sonar sensor measurements taken with calipers:
// 10.82 in between, 42.33 outside, 15.82 diameter
// measured diameter of 15.82 with calipers,
-// but when printed ends up being too small
-sonar_sensor_radius = 15.82 / 2 + 0.3;
-sonar_sensor_height = 13.8;
-between_sensor_centers = 15.82 + 10.82;
-sonar_plate_length = 3 + between_sensor_centers + sonar_sensor_radius + 3;
-sonar_holder_length = sonar_plate_length + 10;
-sonar_holder_width = sonar_plate_width + 3;
-sonar_holder_depth = 4;
+// but when printed ends up being too small, so add some
+sonar_diameter = 15.82 + 0.4;
+sonar_radius = sonar_diameter / 2;
+sonar_height = 13.8;
+between_sonar_centers = sonar_diameter + 10.82;
+// the sonar cylinders are placed on the pcb at slightly different positions
+// from one sensor to the next, so this allows for that variance.
+between_sonar_centers_variance = 2;
+// keep at least this much plastic surrounding the sonar cylinder on all sides
+buffer = 3;
+sonar_holder_length = buffer + between_sonar_centers + sonar_diameter + buffer;
+sonar_holder_width = buffer + sonar_diameter + buffer;
+// sonar_holder_depth is deck_depth minus a little bit to make arm fit
+// into deck holder
+sonar_holder_depth = deck_depth - 0.7875;
-deck_holder_length = 30;
-deck_holder_width = sonar_holder_width;
+deck_holder_length = sonar_holder_depth * 2 + deck_depth + 15;
-module sensors(){
- translate([between_sensor_centers / 2, 0, 0]){
- cylinder(r = sonar_sensor_radius, h = sonar_sensor_height);}
- translate([-between_sensor_centers / 2, 0, 0]){
- cylinder(r = sonar_sensor_radius, h = sonar_sensor_height);}}
+module sonars(){
+ translate([between_sonar_centers / 2, 0, 0]){
+ cylinder(r = sonar_radius, h = sonar_height);}
+ // for the variance with which the physical sonar cylinders are placed
+ translate([between_sonar_centers / 2 - between_sonar_centers_variance, 0, 0]){
+ cylinder(r = sonar_radius, h = sonar_height);
+ translate([0, -sonar_radius, 0]){
+ cube([between_sonar_centers_variance, sonar_diameter, sonar_height]);}}
+ translate([-between_sonar_centers / 2, 0, 0]){
+ cylinder(r = sonar_radius, h = sonar_height);}}
-module sensor_holder(){
+module sonar_holder(){
+ elbow_length = deck_depth - 0.5;
difference(){
cube([sonar_holder_length, sonar_holder_width, sonar_holder_depth]);
translate([sonar_holder_length / 2, sonar_holder_width / 2, -0.05]){
- sensors();}}
+ sonars();}}
translate([sonar_holder_length, 0, 0]){
- cube([sonar_holder_depth + 0.3, deck_depth - 0.3, deck_depth - 0.3]);
- translate([sonar_holder_depth + 0.3, 0, 0]){
- // subtract a little bit (0.3) to make it fit
- cube([deck_depth - 0.3, sonar_holder_width, deck_depth - 0.3]);}}}
+ cube([elbow_length, deck_depth, sonar_holder_depth]);
+ translate([elbow_length, 0, 0]){
+ linear_extrude(height = sonar_holder_depth){
+ polygon([[ 0, 0],
+ [sonar_holder_depth, 0],
+ [sonar_holder_depth, sonar_holder_width / 2],
+ [ 0,
+ sonar_holder_width / 2 + sonar_holder_depth]]);}
+ translate([0, (sonar_holder_width + sonar_holder_depth) / 2, 0]){
+ cube([sonar_holder_depth / 2,
+ (sonar_holder_width - sonar_holder_depth) / 2 + 0.8,
+ sonar_holder_depth]);}
+ translate([-1.7, sonar_holder_width + 0.8, 0]){
+ linear_extrude(height = sonar_holder_depth){
+ polygon([[ 0, 0],
+ [sonar_holder_depth / 2 + 1.7, 4],
+ [sonar_holder_depth / 2 + 1.7, 0]]);}}}}}
module deck_holder(){
- cube([deck_holder_length, sonar_holder_depth, sonar_holder_width]);
- cube([sonar_holder_depth,
- sonar_holder_depth * 2 + deck_depth,
- sonar_holder_width]);
- translate([0, sonar_holder_depth + deck_depth, 0]){
- cube([deck_holder_length, sonar_holder_depth, sonar_holder_width]);}
- translate([sonar_holder_depth + deck_depth, 0, 0]){
- cube([sonar_holder_depth,
- sonar_holder_depth * 2 + deck_depth,
- sonar_holder_width]);}}
-
-module sonar_table_top_holder(){
- difference(){
- union(){
- cube([sonar_holder_length, sonar_holder_width, sonar_holder_depth]);
- translate([sonar_holder_length, 0, 0]){
- deck_holder();}}
- translate([between_sensor_centers / 2 + sonar_sensor_radius + 3,
- sonar_holder_width / 2,
- -1]){
- sensors();}
- // cut out a bit of the circle to make it 3d printable,
- // no severe overhang
- translate([3 + sonar_sensor_radius,
- sonar_holder_width - 3.025,
- sonar_holder_depth / 2 - 0.025]){
- cube([10, 6.1, sonar_holder_depth + .1], center = true);
- translate([between_sensor_centers, 0, 0]){
- cube([10, 6.1, sonar_holder_depth + .1], center = true);}}}}
+ deck_holder_width = sonar_holder_width - deck_depth;
+ deck_holder_height = sonar_holder_depth * 2 + deck_depth;
+ linear_extrude(height = deck_holder_width){
+ difference(){
+ square([deck_holder_length, deck_holder_height]);
+ translate([sonar_holder_depth, sonar_holder_depth]){
+ square(deck_depth);}
+ translate([deck_holder_height, sonar_holder_depth]){
+ square([deck_holder_length - (deck_holder_height), deck_depth]);}}}
+ translate([deck_holder_length - oshw_dy * 0.05, 0, deck_holder_width / 2])
+ scale([0.1, 1, 0.1])
+ rotate(v = [1, 0, 0], a = 90)
+ rotate(90)
+ linear_extrude(height = 0.5)
+ oshw();
+ translate([deck_holder_length - oshw_dy * 0.05,
+ deck_holder_height + 0.5,
+ deck_holder_width / 2])
+ rotate(v = [1, 0, 0], a = 90)
+ rotate(90)
+ scale([0.1, 0.1, 1])
+ linear_extrude(height = 0.5)
+ oshw();}
-sensor_holder();
+deck_holder();
+translate([0, sonar_holder_depth * 2 + deck_depth + 2, 0]){
+ sonar_holder();}