Added printed pcb_mount to hold PCBs without mounting holes.

libtest.scad

@@ -91,6 +91,7 @@ use <tests/strap_handle.scad>
 use <tests/ssr_shroud.scad>
 use <tests/psu_shroud.scad>
 use <tests/flat_hinge.scad>
+use <tests/pcb_mount.scad>
 
 x5 = 800;
 
@@ -304,6 +305,9 @@ translate([x3, veroboard_y])
 translate([x3 + 70, veroboard_y + 30])
     geared_steppers();
 
+translate([x3 + 140, veroboard_y + 20])
+    pcb_mounts();
+
 translate([x3, d_connectors_y])
     d_connectors();
 

printed/pcb_mount.scad

@@ -0,0 +1,124 @@
+//
+// 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 frame to mount a PCB by its corners when it has no mounting holes.
+//! The stl must be given a parameterless wrapper in the project that uses it.
+//
+include <../core.scad>
+include <../vitamins/screws.scad>
+use <../vitamins/pcb.scad>
+
+clearance = 0.2;
+min_wall = extrusion_width * 2;
+wall = 2;
+
+overlap = 2;
+
+screw = M3_cap_screw;
+screw_clearance_r = 3.1 / 2;
+pillar_r = corrected_radius(screw_clearance_r) + wall;
+
+function pillar_x_pitch(pcb) = pcb_length(pcb) + 2 * clearance + 2 * (pillar_r - overlap) / sqrt(2); //! x pitch of screw pillars
+function pillar_y_pitch(pcb) = pcb_width(pcb)  + 2 * clearance + 2 * (pillar_r - overlap) / sqrt(2); //! y pitch of screw pillars
+
+function pcb_mount_length(pcb) = pillar_x_pitch(pcb) + 2 * pillar_r; //! Outside length of the mount
+function pcb_mount_width(pcb)  = pillar_y_pitch(pcb) + 2 * pillar_r; //! Outside width of the mount
+
+frame_w = 3;
+frame_t = 2;
+
+washer_thickness = 1.25;
+
+module pcb_mount_screw_positions(pcb) //! Positions of the screws and pillars
+    for(x = [-1, 1], y = [-1, 1])
+        translate([x * pillar_x_pitch(pcb) / 2, y * pillar_y_pitch(pcb) / 2])
+            children();
+
+module pcb_mount_holes(pcb, h = 0)          //! Drill holes for PCB mount
+    pcb_mount_screw_positions(pcb)
+        drill(screw_clearance_radius(screw), h);
+
+module pcb_mount_ring()
+    difference() {
+        circle(pillar_r);
+
+        poly_circle(screw_clearance_r);
+    }
+
+module pcb_mount_washer_stl() //! A plastic washer to clamp a PCB
+    linear_extrude(height = washer_thickness)
+        pcb_mount_ring();
+
+module pcb_mount(pcb, height = 5, washers = true) { //! Make the STL of a pcb mount for the specified PCB.
+    stl(str("pcb_mount_", pcb[0], "_", height));
+
+    y_pitch = pcb_width(pcb) > 4 * pillar_r + 4 ? pillar_r + 1
+                                                : pcb_width(pcb) / 2 + frame_w + 1 + pillar_r;
+
+    if(washers)
+        for(x = [-1, 1], y = [-1, 1])
+            translate([x * (pillar_r + 1), y * y_pitch, 0])
+                pcb_mount_washer_stl();
+
+    for(x = [-1, 1])
+        translate([x * pillar_x_pitch(pcb) / 2, 0, frame_t / 2])
+            cube([frame_w, pillar_y_pitch(pcb) - 2 * wall, frame_t], center = true);
+
+    for(y = [-1, 1])
+        translate([0, y * pillar_y_pitch(pcb) / 2, frame_t / 2])
+            cube([pillar_x_pitch(pcb) - 2 * wall, frame_w, frame_t], center = true);
+
+    pcb_mount_screw_positions(pcb)
+        linear_extrude(height = height)
+            pcb_mount_ring();
+
+    linear_extrude(height = height + pcb_thickness(pcb) - layer_height)
+        difference() {
+            pcb_mount_screw_positions(pcb)
+                pcb_mount_ring();
+
+            square([pcb_length(pcb) + 2 * clearance, pcb_width(pcb) + 2 * clearance], center = true);
+        }
+}
+
+module pcb_mount_assembly(pcb, thickness, height = 5) { //! A PCB mount assembly with fasteners
+    translate_z(height)
+        pcb(pcb);
+
+    color(pp1_colour) pcb_mount(pcb, washers = false);
+
+    washer = screw_washer(screw);
+    nut = screw_nut(screw);
+    t = pcb_thickness(pcb);
+    screw_length = screw_longer_than(height + t + washer_thickness + thickness + washer_thickness(washer) + nut_thickness(nut, true));
+
+    pcb_mount_screw_positions(pcb) {
+        translate_z(height + t) {
+            color(pp2_colour) pcb_mount_washer_stl();
+
+            translate_z(washer_thickness)
+                screw(screw, screw_length);
+        }
+
+        translate_z(-thickness)
+            vflip()
+                nut_and_washer(nut, true);
+    }
+}

readme.md

@@ -30,13 +30,13 @@ See [usage](docs/usage.md) for requirements, installation instructions and a usa
 <tr><td> <a href = "#Displays">Displays</a> </td><td> <a href = "#Ring_terminals">Ring_terminals</a> </td><td> <a href = "#Flat_hinge">Flat_hinge</a> </td><td> <a href = "#Round">Round</a> </td><td></td></tr>
 <tr><td> <a href = "#Fans">Fans</a> </td><td> <a href = "#Rockers">Rockers</a> </td><td> <a href = "#Foot">Foot</a> </td><td> <a href = "#Rounded_cylinder">Rounded_cylinder</a> </td><td></td></tr>
 <tr><td> <a href = "#Fuseholder">Fuseholder</a> </td><td> <a href = "#Rod">Rod</a> </td><td> <a href = "#Handle">Handle</a> </td><td> <a href = "#Rounded_polygon">Rounded_polygon</a> </td><td></td></tr>
-<tr><td> <a href = "#Geared_steppers">Geared_steppers</a> </td><td> <a href = "#Screws">Screws</a> </td><td> <a href = "#Psu_shroud">Psu_shroud</a> </td><td> <a href = "#Sector">Sector</a> </td><td></td></tr>
+<tr><td> <a href = "#Geared_steppers">Geared_steppers</a> </td><td> <a href = "#Screws">Screws</a> </td><td> <a href = "#Pcb_mount">Pcb_mount</a> </td><td> <a href = "#Sector">Sector</a> </td><td></td></tr>
-<tr><td> <a href = "#Green_terminals">Green_terminals</a> </td><td> <a href = "#Sealing_strip">Sealing_strip</a> </td><td> <a href = "#Ribbon_clamp">Ribbon_clamp</a> </td><td> <a href = "#Sweep">Sweep</a> </td><td></td></tr>
+<tr><td> <a href = "#Green_terminals">Green_terminals</a> </td><td> <a href = "#Sealing_strip">Sealing_strip</a> </td><td> <a href = "#Psu_shroud">Psu_shroud</a> </td><td> <a href = "#Sweep">Sweep</a> </td><td></td></tr>
-<tr><td> <a href = "#Hot_ends">Hot_ends</a> </td><td> <a href = "#Sheets">Sheets</a> </td><td> <a href = "#Screw_knob">Screw_knob</a> </td><td> <a href = "#Tube">Tube</a> </td><td></td></tr>
+<tr><td> <a href = "#Hot_ends">Hot_ends</a> </td><td> <a href = "#Sheets">Sheets</a> </td><td> <a href = "#Ribbon_clamp">Ribbon_clamp</a> </td><td> <a href = "#Tube">Tube</a> </td><td></td></tr>
-<tr><td> <a href = "#Hygrometer">Hygrometer</a> </td><td> <a href = "#Spades">Spades</a> </td><td> <a href = "#Socket_box">Socket_box</a> </td><td></td><td></td></tr>
+<tr><td> <a href = "#Hygrometer">Hygrometer</a> </td><td> <a href = "#Spades">Spades</a> </td><td> <a href = "#Screw_knob">Screw_knob</a> </td><td></td><td></td></tr>
-<tr><td> <a href = "#Iecs">Iecs</a> </td><td> <a href = "#Spools">Spools</a> </td><td> <a href = "#Ssr_shroud">Ssr_shroud</a> </td><td></td><td></td></tr>
+<tr><td> <a href = "#Iecs">Iecs</a> </td><td> <a href = "#Spools">Spools</a> </td><td> <a href = "#Socket_box">Socket_box</a> </td><td></td><td></td></tr>
-<tr><td> <a href = "#Inserts">Inserts</a> </td><td> <a href = "#Springs">Springs</a> </td><td> <a href = "#Strap_handle">Strap_handle</a> </td><td></td><td></td></tr>
+<tr><td> <a href = "#Inserts">Inserts</a> </td><td> <a href = "#Springs">Springs</a> </td><td> <a href = "#Ssr_shroud">Ssr_shroud</a> </td><td></td><td></td></tr>
-<tr><td> <a href = "#Jack">Jack</a> </td><td> <a href = "#Ssrs">Ssrs</a> </td><td></td><td></td><td></td></tr>
+<tr><td> <a href = "#Jack">Jack</a> </td><td> <a href = "#Ssrs">Ssrs</a> </td><td> <a href = "#Strap_handle">Strap_handle</a> </td><td></td><td></td></tr>
 <tr><td> <a href = "#Ldrs">Ldrs</a> </td><td> <a href = "#Stepper_motors">Stepper_motors</a> </td><td></td><td></td><td></td></tr>
 <tr><td> <a href = "#Leadnuts">Leadnuts</a> </td><td> <a href = "#Toggles">Toggles</a> </td><td></td><td></td><td></td></tr>
 <tr><td> <a href = "#Leds">Leds</a> </td><td> <a href = "#Transformers">Transformers</a> </td><td></td><td></td><td></td></tr>
@@ -3851,6 +3851,54 @@ Printed handle that can be printed without needing support material due to its t
 |   1 | handle_assembly |
 
 
+<a href="#top">Top</a>
+
+---
+<a name="Pcb_mount"></a>
+## Pcb_mount
+A frame to mount a PCB by its corners when it has no mounting holes.
+The stl must be given a parameterless wrapper in the project that uses it.
+
+
+[printed/pcb_mount.scad](printed/pcb_mount.scad) Implementation.
+
+[tests/pcb_mount.scad](tests/pcb_mount.scad) Code for this example.
+
+### Functions
+| Function | Description |
+|:--- |:--- |
+| ```pcb_mount_length(pcb)``` | Outside length of the mount |
+| ```pcb_mount_width(pcb)``` | Outside width of the mount |
+| ```pillar_x_pitch(pcb)``` | x pitch of screw pillars |
+| ```pillar_y_pitch(pcb)``` | y pitch of screw pillars |
+
+### Modules
+| Module | Description |
+|:--- |:--- |
+| ```pcb_mount(pcb, height = 5, washers = true)``` | Make the STL of a pcb mount for the specified PCB. |
+| ```pcb_mount_assembly(pcb, thickness, height = 5)``` | A PCB mount assembly with fasteners |
+| ```pcb_mount_holes(pcb, h = 0)``` | Drill holes for PCB mount |
+| ```pcb_mount_screw_positions(pcb)``` | Positions of the screws and pillars |
+| ```pcb_mount_washer_stl()``` | A plastic washer to clamp a PCB |
+
+![pcb_mount](tests/png/pcb_mount.png)
+
+### Vitamins
+| Qty | Module call | BOM entry |
+| ---:|:--- |:---|
+|   4 | ```nut(M3_nut, nyloc = true)``` |  Nut M3 x 2.4mm nyloc |
+|   1 | ```pcb(PI_IO)``` |  PI_IO V2 |
+|   1 | ```pin_socket(2p54header, 13, 2)``` |  Pin socket 13 x 2 |
+|   4 | ```screw(M3_cap_screw, 16)``` |  Screw M3 cap x 16mm |
+|   3 | ```terminal_35(2)``` |  Terminal block 2 way 3.5mm |
+|   4 | ```washer(M3_washer)``` |  Washer  M3 x 7mm x 0.5mm |
+
+### Printed
+| Qty | Filename |
+| ---:|:--- |
+|   1 | pcb_mount_PI_IO_5.stl |
+
+
 <a href="#top">Top</a>
 
 ---

tests/pcb_mount.scad

@@ -0,0 +1,35 @@
+//
+// 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/>.
+//
+include <../lib.scad>
+use <../printed/pcb_mount.scad>
+
+PI_IO = ["PI_IO", "PI_IO V2",       35.56, 25.4, 1.6, 0,    0,   0, "green", true, [],
+    [[(3.015 - 2.7) * 25.4 - 3.5 /2, (4.5 - 3.685) * 25.4, 90, "term35", 2],
+     [(3.46  - 2.7) * 25.4 - 3.5 /2, (4.5 - 3.69)  * 25.4, 90, "term35", 2],
+     [(3.91  - 2.7) * 25.4 - 3.5 /2, (4.5 - 3.69)  * 25.4, 90, "term35", 2],
+     [(3.4   - 2.7) * 25.4,          (4.5 - 4.15)  * 25.4,  0, "2p54socket", 13, 2],
+    ], []];
+
+module pcb_mounts()
+    if($preview)
+        pcb_mount_assembly(PI_IO, 3);
+    else
+        pcb_mount(PI_IO);
+
+pcb_mounts();