Added printed knobs for pots.

tests/knob.scad

@@ -0,0 +1,57 @@
+//
+// NopSCADlib Copyright Chris Palmer 2021
+// 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/>.
+//
+z = 1; // [0: 5]
+thickness = 3; // [0: 5]
+shaft_length = 10;
+
+include <../utils/core/core.scad>
+use <../printed/knob.scad>
+use <../utils/layout.scad>
+
+include <../vitamins/potentiometers.scad>
+
+knobs = [for(i = [0 : len(potentiometers) - 1]) let(p = potentiometers[i])
+     knob_for_pot(p, thickness, z, shaft_length = pot_shaft(p).z > 20 ? shaft_length : undef,
+                  top_d   = [10,    12,      20,    16,        16       ][i],
+                  bot_d   = [10,    15,      20,    20,        20       ][i],
+                  skirt   = [false, [20, 2], false,      [27, 1.5], [27, 1.5]][i],
+                  pointer = [false, false,   [14, [1, 5], 2], [13.5, [1, 1], 3], [13.5, [1, 3], 3]][i]
+                 )];
+
+
+module knobs(show_pot = false)
+    layout([for(p = potentiometers) pot_size(p).x], 5) let(p = potentiometers[$i])
+        if($preview) {
+            translate_z(z)
+                knob_assembly(knobs[$i]);
+
+            if(show_pot)
+                translate_z(-thickness)
+                    vflip() {
+                        potentiometer(p, shaft_length = shaft_length);
+
+                        translate_z(-thickness)
+                            pot_nut(p);
+                    }
+        }
+        else
+            knob(knobs[$i]);
+
+
+knobs(true);