small fixes

SMALLEST_POSSIBLE fixes originating from talks in the openSCAD repo about float rounding issues w/r/t STL. couple more I don't remember 😕

keys.scad

@@ -14,4 +14,7 @@ include <src/key_types.scad>
 include <src/key_transformations.scad>
 include <src/key_helpers.scad>
 
-key();
+sa_row(3) u(3) stabilized() {
+  /* %envelope(0); */
+  key();
+}

src/constants.scad

@@ -0,0 +1 @@
+SMALLEST_POSSIBLE = 1/128;

src/functions.scad

@@ -1,3 +1,5 @@
+include <constants.scad>
+
 // I use functions when I need to compute special variables off of other special variables
 // functions need to be explicitly included, unlike special variables, which
 // just need to have been set before they are used. hence this file
@@ -16,7 +18,7 @@ function cherry_cross(slop, extra_vertical = 0) = [
   // horizontal tine
   [4.03 + slop, 1.15 + slop / 3],
   // vertical tine
-  [1.25 + slop / 3, 4.23 + extra_vertical + slop / 3 + .005],
+  [1.25 + slop / 3, 4.23 + extra_vertical + slop / 3 + SMALLEST_POSSIBLE],
 ];
 
 // actual mm key width and height

src/key.scad

@@ -11,6 +11,7 @@ include <libraries/geodesic_sphere.scad>
 
 
 /* [Hidden] */
+SMALLEST_POSSIBLE = 1/128;
 $fs = .1;
 $unit = 19.05;
 blue = [.2667,.5882,1];
@@ -22,7 +23,7 @@ transparent_red = [1,0,0, 0.15];
 // key shape including dish. used as the ouside and inside shape in keytop(). allows for itself to be shrunk in depth and width / height
 module shape(thickness_difference, depth_difference){
   dished(depth_difference, $inverted_dish) {
-    color(blue) shape_hull(thickness_difference, depth_difference, 2);
+    color(blue) shape_hull(thickness_difference, depth_difference, $inverted_dish ? 2 : 0);
   }
 }
 
@@ -87,7 +88,7 @@ module shape_slice(progress, thickness_difference, depth_difference) {
 
   translate([0, skew_this_slice, depth_this_slice]) {
     rotate([tilt_this_slice,0,0]){
-      linear_extrude(height = 0.001){
+      linear_extrude(height = SMALLEST_POSSIBLE){
         key_shape(
           [
             total_key_width(thickness_difference),
@@ -128,7 +129,7 @@ module envelope(depth_difference) {
   s = 1.5;
   hull(){
     cube([total_key_width() * s, total_key_height() * s, 0.01], center = true);
-    top_placement(0.005 + depth_difference){
+    top_placement(SMALLEST_POSSIBLE + depth_difference){
       cube([top_total_key_width() * s, top_total_key_height() * s, 0.01], center = true);
     }
   }
@@ -257,7 +258,7 @@ module keytop() {
       shape(0, 0);
     }
     // translation purely for aesthetic purposes, to get rid of that awful lattice
-    translate([0,0,-0.005]) {
+    translate([0,0,-SMALLEST_POSSIBLE]) {
       shape($wall_thickness, $keytop_thickness);
     }
   }
@@ -289,7 +290,7 @@ module key(inset = false) {
   if ($stem_type != "disable" || ($stabilizers != [] && $stabilizer_type != "disable")) {
     dished($keytop_thickness, $inverted_dish) {
       translate([0, 0, $stem_inset]) {
-        if ($stabilizer_type != "disable") stems_for($stabilizers, $stabilizer_type);
+        /* if ($stabilizer_type != "disable") stems_for($stabilizers, $stabilizer_type); */
         if ($stem_type != "disable") stems_for($stem_positions, $stem_type);
       }
     }

src/stem_supports/tines.scad

@@ -1,8 +1,9 @@
 include <../functions.scad>
 include <../stems/cherry.scad>
 
+// $wall_thickness/4 to reduce coincident faces
 module centered_tines(stem_support_height) {
-  if ($key_length < 2) translate([0,0,$stem_support_height / 2]) cube([total_key_width($wall_thickness), 1, $stem_support_height], center = true);
+  if ($key_length < 2) translate([0,0,$stem_support_height / 2]) cube([total_key_width($wall_thickness)+$wall_thickness/4, 1, $stem_support_height], center = true);
   translate([0,0,$stem_support_height / 2]) cube([1, total_key_height($wall_thickness), $stem_support_height], center = true);
 }
 
@@ -10,7 +11,7 @@ module tines_support(stem_type, stem_support_height, slop) {
   if (stem_type == "cherry" || stem_type == "costar_stabilizer") {
     difference () {
       union() {
-        if ($key_length < 2) translate([0,0,$stem_support_height / 2]) cube([total_key_width($wall_thickness), 1, $stem_support_height], center = true);
+        if ($key_length < 2) translate([0,0,$stem_support_height / 2]) cube([total_key_width($wall_thickness)+$wall_thickness/4, 1, $stem_support_height], center = true);
         translate([1.15,0,$stem_support_height / 2]) cube([.5, total_key_height($wall_thickness), $stem_support_height], center = true);
         translate([-1.15,0,$stem_support_height / 2]) cube([.5, total_key_height($wall_thickness), $stem_support_height], center = true);
       }

src/stems/cherry.scad

@@ -7,7 +7,7 @@ extra_vertical = 0.6;
 module inside_cherry_cross(slop) {
   // inside cross
   // translation purely for aesthetic purposes, to get rid of that awful lattice
-  translate([0,0,-0.005]) {
+  translate([0,0,-SMALLEST_POSSIBLE]) {
     linear_extrude(height = $stem_throw) {
       square(cherry_cross(slop, extra_vertical)[0], center=true);
       square(cherry_cross(slop, extra_vertical)[1], center=true);

src/stems/cherry_stabilizer.scad

@@ -7,7 +7,7 @@ extra_vertical = 0.6;
 module inside_cherry_stabilizer_cross(slop) {
   // inside cross
   // translation purely for aesthetic purposes, to get rid of that awful lattice
-  translate([0,0,-0.005]) {
+  translate([0,0,-SMALLEST_POSSIBLE]) {
     linear_extrude(height = $stem_throw) {
       square(cherry_cross(slop, extra_vertical)[0], center=true);
       square(cherry_cross(slop, extra_vertical)[1], center=true);