Added male screw threads.

global_defs.scad

@@ -39,6 +39,7 @@ pp2_colour      = is_undef($pp2_colour)      ? "red"  : $pp2_colour;      // pri
 pp3_colour      = is_undef($pp3_colour)      ? "blue" : $pp3_colour;      // printed part colour 3
 pp4_colour      = is_undef($pp4_colour)      ? "darkorange" : $pp4_colour;// printed part colour 4
 show_rays       = is_undef($show_rays)       ? false  : $show_rays;       // show camera sight lines and light direction
+show_threads    = is_undef($show_threads)    ? false  : $show_threads;    // show screw threads
 
 // Minimum wall is about two filaments wide but we extrude it closer to get better bonding
 squeezed_wall = $preview ? 2 * extrusion_width - layer_height * (1 - PI / 4)
@@ -59,7 +60,8 @@ grey60                          = [0.6, 0.6, 0.6];
 grey70                          = [0.7, 0.7, 0.7];
 grey80                          = [0.8, 0.8, 0.8];
 grey90                          = [0.9, 0.9, 0.9];
-brass                           = "gold";
+brass                           = [255/255, 215/255, 0/255];
+silver                          = [0.75, 0.75, 0.75];
 
 /*
  * Enums

lib.scad

@@ -90,3 +90,4 @@ use <utils/layout.scad>
 use <utils/round.scad>
 use <utils/offset.scad>
 use <utils/sector.scad>
+use <utils/thread.scad>

scripts/views.py

@@ -154,7 +154,7 @@ def views(target, do_assemblies = None):
                                         f.write("use <%s/%s>\n" % (dir, filename))
                                         f.write("%s();\n" % module);
                                     #
-                                    # Run openscad on th created file
+                                    # Run openscad on the created file
                                     #
                                     dname = deps_name(deps_dir, filename)
                                     for explode in [0, 1]:
@@ -167,7 +167,7 @@ def views(target, do_assemblies = None):
                                         if changed:
                                             print(changed)
                                             t = time.time()
-                                            openscad.run("-D$pose=1", "-D$explode=%d" % explode, colour_scheme, "--projection=p", "--imgsize=4096,4096", "--autocenter", "--viewall", "-d", dname, "-o", tmp_name, png_maker_name);
+                                            openscad.run("-D$show_threads=1", "-D$pose=1", "-D$explode=%d" % explode, colour_scheme, "--projection=p", "--imgsize=4096,4096", "--autocenter", "--viewall", "-d", dname, "-o", tmp_name, png_maker_name);
                                             times.add_time(png_name, t)
                                             do_cmd(["magick", tmp_name, "-trim", "-resize", "1004x1004", "-bordercolor", background, "-border", "10", tmp_name])
                                             update_image(tmp_name, png_name)

tests/d_connectors.scad

@@ -35,4 +35,5 @@ module d_connectors()
                 }
 
 if($preview)
-    d_connectors();
+    let($show_threads = true)
+        d_connectors();

tests/pillars.scad

@@ -26,4 +26,5 @@ module pillars()
         pillar(pillars[$i]);
 
 if($preview)
-    pillars();
+    let($show_threads = true)
+        pillars();

tests/rod.scad

@@ -33,4 +33,5 @@ module rods()
     }
 
 if($preview)
-    rods();
+    let($show_threads = true)
+        rods();

tests/screws.scad

@@ -34,4 +34,5 @@ for(y = [0 : len(screw_lists) -1])
     }
 
 if($preview)
-    screws();
+    let($show_threads = true)
+        screws();

utils/core/global.scad

@@ -43,7 +43,7 @@ module ellipse(xr, yr) scale([1, yr / xr]) circle4n(xr);
 
 module extrude_if(h, center = true)                 //! Extrudes 2D object to 3D when ```h``` is nonzero, otherwise leaves it 2D
     if(h)
-        linear_extrude(height = h, center = center) // 3D
+        linear_extrude(height = h, center = center, convexity = 2) // 3D
             children();
     else
         children();                                 // 2D

utils/thread.scad

@@ -0,0 +1,114 @@
+//
+// NopSCADlib Copyright Chris Palmer 2019
+// nop.head@gmail.com
+// hydraraptor.blogspot.com
+//
+// This file is part of NopSCADlib.
+//
+// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
+// GNU General Public License as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// NopSCADlib 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 General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with NopSCADlib.
+// If not, see <https://www.gnu.org/licenses/>.
+//
+
+//
+//! A utilities for making threads with sweep.
+//
+include <../core.scad>
+use <sweep.scad>
+use <maths.scad>
+
+function thread_profile(h, crest, angle) = //! Create thread profile path
+    let(base = crest + 2 * h * tan(angle / 2))
+        [[-base / 2, 0, 0], [-crest / 2, h, 0], [crest / 2, h, 0], [base / 2, 0, 0]];
+
+module male_thread(pitch, minor_d, length, profile, taper_top = true, center = true, solid = true) { //! Create male thread
+    turns = length / pitch + (taper_top ? 0 : 1);
+    r = minor_d / 2;
+    sides = r2sides(r);
+    h = max([for(p = profile) p.y]);
+    final = (turns - 1) * sides;
+    path = [for(i = [0 : sides * turns],
+                R = i < sides ? r - h + h * i / sides
+                    : i > final && taper_top ? r - h * (i - final) / sides : r,
+                a = i * 360 / sides)
+                    [R * sin(-a), R * cos(-a), pitch * a / 360]];
+    t = atan(pitch / sides / (r * cos(225 / sides)));
+    translate_z(center ? -length / 2 : 0) {
+        render() intersection() {
+            sweep(path, profile, twist = t * sides * turns);
+            cylinder(d = minor_d + 5, h = length);
+        }
+        if(solid)
+            rotate(90)
+                cylinder(d = minor_d + eps, h = length);
+    }
+}
+
+module female_thread(pitch, outer_d, length, profile, taper_top = true, center = true) { //! Create female thread
+    turns = length / pitch + (taper_top ? 0 : 1);
+    r = outer_d / 2;
+    sides = r2sides(r);
+    h = max([for(p = profile) p.y]);
+    final = (turns - 1) * sides;
+    path = [for(i = [0 : sides * turns],
+                R = i < sides ? r + h - h * i / sides
+                    : i > final && taper_top ? r + h * (i - final) / sides : r,
+                a = i * 360 / sides)
+                    [R * sin(-a), R * cos(-a), pitch * a / 360]];
+    t = atan(pitch / sides / (r * cos(225 / sides)));
+    translate_z(center ? -length / 2 : 0) {
+        render() intersection() {
+            sweep(path, reverse([for(p = profile) [p.x, -p.y, 0]]), twist = t * sides * turns);
+            cylinder(d = outer_d + 5, h = length);
+        }
+    }
+}
+
+module male_metric_thread(d, pitch, length, taper_top = true, center = true) { //! Create male thread with metric profile
+    h = sqrt(3) / 2 * pitch;
+    minor_d = d - 5 * h / 4;
+    male_thread(pitch, minor_d, length, thread_profile((d - minor_d) / 2, pitch / 8, 60), taper_top, center);
+}
+
+module female_metric_thread(d, pitch, length, taper_top = true, center = true) { //! Create male thread with metric profile
+    h = sqrt(3) / 2 * pitch;
+    outer_d = d + 5 * h / 4;
+    male_thread(pitch, outer_d, length, thread_profile((outer_d - d) / 2, pitch / 8, 60), taper_top, center);
+}
+
+function metric_coarse_pitch(d) //! Convert metric diameter to pitch
+    = d == 1.6 ? 0.35  // M1.6
+               : [0.4, // M2
+                  0.45,// M2.5
+                  0.5, // M3
+                  0.6, // M3.5
+                  0.7, // M4
+                  0,
+                  0.8, // M5
+                  0,
+                  1.0, // M6
+                  0,
+                  0,
+                  0,
+                  1.25, // M8
+                  0,
+                  0,
+                  0,
+                  1.5,  // M10
+                  0,
+                  0,
+                  0,
+                  1.75, // M12
+                 ][d * 2 - 4];
+
+male_metric_thread(3, 0.5, 25);
+
+translate([10, 0])
+male_metric_thread(8, 1.25, 30);

vitamins/d_connector.scad

@@ -21,6 +21,7 @@
 //! D-connectors. Can be any number of ways, male or female, solder buckets, PCB mount or IDC, with or without pillars.
 //
 include <../core.scad>
+use <../utils/thread.scad>
 
 d_pillar_color                   = grey90;
 d_plug_shell_color               = grey80;
@@ -51,16 +52,21 @@ module d_pillar() { //! Draw a pillar for a D-connector
     height = 4.5;
     screw = 2.5;
     screw_length = 8;
-    color(d_pillar_color)  {
-        translate_z(-screw_length)
-            cylinder(d = screw, h = screw_length + 1);
 
+    translate_z(-screw_length)
+        if(show_threads)
+            color(d_pillar_color * 0.7)
+                male_metric_thread(screw, metric_coarse_pitch(screw), screw_length, false, false);
+        else
+            color(d_pillar_color)
+                cylinder(d = screw, h = screw_length + 1);
+
+    color(d_pillar_color)
         linear_extrude(height = height)
             difference() {
                 circle(r = rad, $fn = 6);
                 circle(d = screw);
             }
-    }
 }
 
 module d_plug(type, socket = false, pcb = false, idc = false) { //! Draw specified D plug, which can be IDC, PCB or plain solder bucket

vitamins/pillar.scad

@@ -21,6 +21,7 @@
 //! Threaded pillars. Each end can be male or female.
 //
 include <../core.scad>
+use <../utils/thread.scad>
 
 function pillar_name(type)       = type[1];     //! Name of part
 function pillar_thread(type)     = type[2];     //! Thread diameter
@@ -41,30 +42,43 @@ module pillar(type) { //! Draw specified pillar
     sex = str(sex(pillar_bot_thread(type)),"/", sex(pillar_top_thread(type)));
     height = pillar_height(type);
     thread_d = pillar_thread(type);
+    bot_thread_l = pillar_bot_thread(type);
+    top_thread_l = pillar_top_thread(type);
+    thread_colour = pillar_i_colour(type) * (show_threads ? 0.7 : 1);
 
     vitamin(str("pillar(", type[0], "): Pillar ", pillar_name(type), " ", sex, " M", thread_d, "x", height));
 
+    color(thread_colour) {
+        if(bot_thread_l > 0)
+            translate_z(-bot_thread_l + eps)
+                if(show_threads)
+                    male_metric_thread(thread_d, metric_coarse_pitch(thread_d), bot_thread_l, false, false);
+                else
+                    cylinder(h = bot_thread_l, d = thread_d);
+
+        if(top_thread_l > 0)
+            translate_z(height + top_thread_l - eps)
+                if(show_threads)
+                    vflip()
+                        male_metric_thread(thread_d, metric_coarse_pitch(thread_d), top_thread_l, false, false);
+                else
+                    cylinder(h = top_thread_l, d = thread_d);
+    }
+
     color(pillar_i_colour(type))  {
-        if(pillar_bot_thread(type) > 0)
-            translate_z(-pillar_bot_thread(type))
-                cylinder(h = pillar_bot_thread(type) + eps, d = pillar_thread(type));
-
-        if(pillar_top_thread(type) > 0)
-            translate_z(height - eps)
-                cylinder(h = pillar_top_thread(type) + eps, d = pillar_thread(type));
-
         linear_extrude(height = height)
             difference() {
                 circle(d = pillar_id(type), $fn = fn(pillar_ifn(type)));
-                circle(d = pillar_thread(type));
+                circle(d = thread_d);
             }
 
-        top = height + min(pillar_top_thread(type), 0);
-        bot = -min(pillar_bot_thread(type), 0);
+        top = height + min(top_thread_l, 0);
+        bot = -min(bot_thread_l, 0);
 
         translate_z(bot)
-            cylinder(h = top - bot,  d = pillar_thread(type) + eps);
+            cylinder(h = top - bot,  d = thread_d + eps);
     }
+
     if(pillar_od(type) > pillar_id(type))
         color(pillar_o_colour(type)) linear_extrude(height = height)
             difference() {

vitamins/pillars.scad

@@ -30,8 +30,8 @@
 //                                                               d                                   r         r         d   d
 //
 M2x16_brass_pillar     = ["M2x16_brass_pillar",     "nurled",    2, 16, 3.17,      3.17,       0, 0, brass,     brass,    3,-3];
-M3x13_hex_pillar       = ["M3x13_hex_pillar",       "hex",       3, 13, 5/cos(30), 5/cos(30),  6, 6, "silver", "silver", -6, 6];
-M3x20_hex_pillar       = ["M3x20_hex_pillar",       "hex",       3, 20, 5/cos(30), 5/cos(30),  6, 6, "silver", "silver", -8, 8];
+M3x13_hex_pillar       = ["M3x13_hex_pillar",       "hex",       3, 13, 5/cos(30), 5/cos(30),  6, 6, "silver",  silver,  -6, 6];
+M3x20_hex_pillar       = ["M3x20_hex_pillar",       "hex",       3, 20, 5/cos(30), 5/cos(30),  6, 6, "silver",  silver,  -8, 8];
 M3x20_nylon_pillar     = ["M3x20_nylon_pillar",     "nylon",     3, 20, 8,         5/cos(30),  0, 6, "white",   brass,   -6, 6];
 M4x17_nylon_pillar     = ["M4x17_nylon_pillar",     "nylon",     4, 20, 8,         5/cos(30),  0, 6, "white",   brass,   -6, 6];
 M3x20_nylon_hex_pillar = ["M3x20_nylon_hex_pillar", "hex nylon", 3, 20, 8/cos(30), 8/cos(30),  6, 6,  grey20,   grey20,  -6, 6];

vitamins/rod.scad

@@ -21,6 +21,7 @@
 //! Steel rods and studding with chamfered ends.
 //
 include <../core.scad>
+use <../utils/thread.scad>
 
 rod_colour = grey80;
 studding_colour = grey70;
@@ -41,10 +42,14 @@ module studding(d , l) { //! Draw a threaded rod with specified length and diame
     vitamin(str("studding(", d, ", ", l,"): Threaded rod M", d, " x ", l, "mm"));
 
     chamfer = d / 20;
+    pitch = metric_coarse_pitch(d);
     color(studding_colour)
-        hull() {
-            cylinder(d = d, h = l - 2 * chamfer, center = true);
+        if(show_threads && pitch)
+            male_metric_thread(d, pitch, l);
+        else
+            hull() {
+                cylinder(d = d, h = l - 2 * chamfer, center = true);
 
-            cylinder(d = d - 2 * chamfer, h = l, center = true);
-        }
+                cylinder(d = d - 2 * chamfer, h = l, center = true);
+            }
 }

vitamins/screw.scad

@@ -24,6 +24,7 @@ include <../core.scad>
 
 use <washer.scad>
 use <../utils/rounded_cylinder.scad>
+use <../utils/thread.scad>
 
 function screw_head_type(type)        = type[2];     //! Head style hs_cap, hs_pan, hs_cs, hs_hex, hs_grub, hs_cs_cap, hs_dome
 function screw_radius(type)           = type[3] / 2; //! Nominal radius
@@ -69,24 +70,33 @@ module screw(type, length, hob_point = 0, nylon = false) { //! Draw specified sc
     socket_depth= screw_socket_depth(type);
     socket_rad  = socket_af / cos(30) / 2;
     max_thread  = screw_max_thread(type);
-    thread = max_thread ? min(length, max_thread) : length;
+    thread = max_thread ? length >= max_thread + 5 ? max_thread
+                                                   : length
+                        : length;
     shank  = length - thread;
     colour = nylon || head_type == hs_grub ? grey40 : grey80;
 
-
     module shaft(headless = 0) {
         point = screw_nut(type) ? 0 : 3 * rad;
-        color(colour * 0.9 )
-            rotate_extrude() {
-                translate([0, -length + point])
-                    square([rad, length - headless - point]);
+        d = 2 * screw_radius(type);
+        pitch = metric_coarse_pitch(d);
+        l = length - shank;
+        if(show_threads && !point && pitch)
+            translate_z(-l - shank)
+                color(colour * 0.7)
+                    male_metric_thread(d, pitch, l, !!headless, false);
+        else
+            color(colour * 0.9)
+                rotate_extrude() {
+                    translate([0, -length + point])
+                        square([rad, length - headless - point]);
 
-                if(point)
-                    polygon([
-                        [0, -length], [0, point - length], [rad - 0.1, point - length]
-                    ]);
-            }
-        if(shank >= 5)
+                    if(point)
+                        polygon([
+                            [0, -length], [0, point - length], [rad - 0.1, point - length]
+                        ]);
+                }
+        if(shank - headless > 0)
             color(colour)
                 translate_z(-shank)
                     cylinder(r = rad + eps, h = shank - headless);
@@ -102,6 +112,7 @@ module screw(type, length, hob_point = 0, nylon = false) { //! Draw specified sc
                     linear_extrude(height = socket_depth)
                         difference() {
                             circle(head_rad);
+
                             circle(socket_rad, $fn = 6);
                         }
 
@@ -110,14 +121,23 @@ module screw(type, length, hob_point = 0, nylon = false) { //! Draw specified sc
         }
         if(head_type == hs_grub) {
             color(colour) {
-                translate_z(-socket_depth)
-                    linear_extrude(height = socket_depth)
-                        difference() {
-                            circle(r = rad);
-                            circle(socket_rad, $fn = 6);
-                        }
+                if(!show_threads) {
+                    translate_z(-socket_depth)
+                        linear_extrude(height = socket_depth)
+                            difference() {
+                                circle(r = rad);
 
-                shaft(socket_depth);
+                                circle(socket_rad, $fn = 6);
+                            }
+
+                    shaft(socket_depth);
+                }
+                else
+                    render() difference() {
+                        shaft(socket_depth);
+
+                        cylinder(r = socket_rad, $fn = 6, h = 2 * socket_depth, center = true);
+                    }
             }
         }
         if(head_type == hs_hex) {