switch to linear extrude for arm of sonar holder

[challenge-bot] / 3d-printables / sonar-table-top-holder.scad

diff --git a/3d-printables/sonar-table-top-holder.scad b/3d-printables/sonar-table-top-holder.scad
index 9cb881de5609da37309af24bcb85dd60511fba9d..e3535d90a52afa6d7050eee0df699e9ad3c824f3 100644 (file)
--- a/3d-printables/sonar-table-top-holder.scad
+++ b/3d-printables/sonar-table-top-holder.scad
@@ -7,8 +7,9 @@
 $fn = 60;
 
 // 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;
+// 1/4 inch in mm = 6.35
+// subtract a little to be a squeeze fit
+deck_depth = 4.7625 - 0.4;
 sonar_plate_width = 20;
 // sonar sensor measurements taken with calipers:
 //  10.82 in between, 42.33 outside, 15.82 diameter
@@ -16,61 +17,69 @@ sonar_plate_width = 20;
 //  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;
+between_sensor_centers = sonar_sensor_radius * 2 + 10.82;
+between_sensor_centers_variance = 2;
+buffer = 3;
+sonar_plate_length =
+  buffer + between_sensor_centers + sonar_sensor_radius + buffer;
 sonar_holder_length = sonar_plate_length + 10;
 sonar_holder_width = sonar_plate_width + 3;
-sonar_holder_depth = 4;
+// sonar_holder_depth is deck_depth minus a little bit to make arm fit
+//  into deck holder
+sonar_holder_depth = deck_depth - 0.8;
 
-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 - between_sensor_centers_variance,
+             0,
+             0]){
+    cylinder(r = sonar_sensor_radius, h = sonar_sensor_height);
+    translate([0, -sonar_sensor_radius, 0]){
+      cube([between_sensor_centers_variance,
+            sonar_sensor_radius * 2,
+            sonar_sensor_height]);}}
   translate([-between_sensor_centers / 2, 0, 0]){
     cylinder(r = sonar_sensor_radius, h = sonar_sensor_height);}}
 
 module sensor_holder(){
+  arm_depth = sonar_holder_depth;
+  elbow_length = deck_depth + 0.8;
   difference(){
     cube([sonar_holder_length, sonar_holder_width, sonar_holder_depth]);
     translate([sonar_holder_length / 2, sonar_holder_width / 2, -0.05]){
       sensors();}}
-  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]);}}}
+  translate([sonar_holder_length - 1, 0, 0]){
+    cube([elbow_length + arm_depth + 1, deck_depth, arm_depth]);
+    translate([elbow_length + 1, 0, 0]){
+      linear_extrude(height = arm_depth){
+        polygon([[0, 0],
+                 [arm_depth, 0],
+                 [arm_depth, sonar_holder_width / 2],
+                 [0, sonar_holder_width / 2 + arm_depth]]);}
+      translate([0, (sonar_holder_width + arm_depth) / 2, 0]){
+        cube([arm_depth / 2,
+              (sonar_holder_width - arm_depth) / 2 + 0.8,
+              arm_depth]);}
+      translate([-1.7, sonar_holder_width + 0.8, 0]){
+        linear_extrude(height = arm_depth){
+          polygon([[0, 0],
+                   [arm_depth / 2 + 1.7, 4],
+                   [arm_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]);}}
+  deck_holder_width = sonar_holder_width - deck_depth;
+  linear_extrude(height = deck_holder_width){
+    difference(){
+      square([deck_holder_length, sonar_holder_depth * 2 + deck_depth]);
+      translate([sonar_holder_depth, sonar_holder_depth]){
+        square(deck_depth);}
+      translate([sonar_holder_depth * 2 + deck_depth, sonar_holder_depth]){
+        square([deck_holder_length - (sonar_holder_depth * 2 + deck_depth),
+                deck_depth]);}}}}
 
-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);}}}}
-
-sensor_holder();
+translate([0, sonar_holder_depth * 2 + deck_depth + 2, 0]){
+  sensor_holder();}
+deck_holder();