Type in drag chain blurb, fixes #100

Added blower_exit_offset().
Fixed corner shape and exit dimensions.
Updated images and readme.

libtest.scad

@@ -52,6 +52,7 @@ use <tests/circlips.scad>
 use <tests/components.scad>
 use <tests/d_connectors.scad>
 use <tests/displays.scad>
+use <tests/drag_chain.scad>
 use <tests/extrusions.scad>
 use <tests/extrusion_brackets.scad>
 use <tests/fans.scad>
@@ -417,8 +418,12 @@ translate([x4 + 200, belts_y + 58]) {
 
     translate([0, 60])
         opengrab_test();
+
 }
 
+translate([x4 + 175, belts_y, -20])
+    drag_chains();
+
 translate([x4, rails_y + 130])
     rails();
 

printed/drag_chain.scad

@@ -22,7 +22,7 @@
 //!
 //! Each link has a maximum bend angle of 45°, so the mininium radius is proportional to the link length.
 //!
-//! The travel prpoery is how far it can move in each direction, i.e. half the maximum travel if the chain is mounted in the middle of the travel.
+//! The travel property is how far it can move in each direction, i.e. half the maximum travel if the chain is mounted in the middle of the travel.
 //
 
 include <../core.scad>

printed/ribbon_clamp.scad

@@ -117,9 +117,13 @@ module ribbon_clamp_fastened_assembly(ways, thickness, screw = screw) { //! Clam
 
 module ribbon_clamp_20_stl() ribbon_clamp(20);
 module ribbon_clamp_8_2_stl() ribbon_clamp(8, M2_dome_screw);
+module ribbon_clamp_7_2_stl() ribbon_clamp(8, M2_dome_screw);
 
 //! * Place inserts into the holes and press home with a soldering iron with a conical bit heated to 200°C.
 module ribbon_clamp_20_assembly() ribbon_clamp_assembly(20);
 
 //! * Place inserts into the holes and press home with a soldering iron with a conical bit heated to 200°C.
 module ribbon_clamp_8_2_assembly() ribbon_clamp_assembly(8, M2_dome_screw);
+
+//! * Place inserts into the holes and press home with a soldering iron with a conical bit heated to 200°C.
+module ribbon_clamp_7_2_assembly() ribbon_clamp_assembly(8, M2_dome_screw);

readme.md

@@ -296,11 +296,18 @@ Models of radial blowers.
 | ```blower_wall(type)``` | Side wall thickness |
 | ```blower_width(type)``` | Width of enclosing rectangle |
 
+### Functions
+| Function | Description |
+|:--- |:--- |
+| ```blower_casing_is_square(type)``` | True for square radial fans, false for spiral shape radial blowers |
+| ```blower_exit_offset(type)``` | Offset of exit's centre from the edge |
+
 ### Modules
 | Module | Description |
 |:--- |:--- |
 | ```blower(type)``` | Draw specified blower |
 | ```blower_hole_positions(type)``` | Translate children to screw hole positions |
+| ```blower_square(type)``` | Draw a square blower |
 
 ![blowers](tests/png/blowers.png)
 
@@ -309,8 +316,11 @@ Models of radial blowers.
 | ---:|:--- |:---|
 |   1 | ```blower(PE4020)``` |  Blower Pengda Technology 4020 |
 |   1 | ```blower(RB5015)``` |  Blower Runda RB5015 |
+|   4 | ```screw(M2_cap_screw, 8)``` |  Screw M2 cap x  8mm |
 |   3 | ```screw(M3_cap_screw, 20)``` |  Screw M3 cap x 20mm |
 |   2 | ```screw(M4_cap_screw, 25)``` |  Screw M4 cap x 25mm |
+|   1 | ```blower(BL40x10)``` |  Square radial 4010 |
+|   4 | ```washer(M2_washer)``` |  Washer  M2 x 5mm x 0.3mm |
 |   3 | ```washer(M3_washer)``` |  Washer  M3 x 7mm x 0.5mm |
 |   2 | ```washer(M4_washer)``` |  Washer  M4 x 9mm x 0.8mm |
 
@@ -4548,7 +4558,7 @@ Parametric cable drag chain to limit the bend radius of a cable run.
 
 Each link has a maximum bend angle of 45°, so the mininium radius is proportional to the link length.
 
-The travel prpoery is how far it can move in each direction, i.e. half the maximum travel if the chain is mounted in the middle of the travel.
+The travel property is how far it can move in each direction, i.e. half the maximum travel if the chain is mounted in the middle of the travel.
 
 
 [printed/drag_chain.scad](printed/drag_chain.scad) Implementation.

vitamins/blower.scad

@@ -22,6 +22,8 @@
 //
 include <../utils/core/core.scad>
 use <../utils/rounded_cylinder.scad>
+use <../utils/quadrant.scad>
+use <screw.scad>
 
 function blower_length(type)      = type[2]; //! Length of enclosing rectangle
 function blower_width(type)       = type[3]; //! Width of enclosing rectangle
@@ -39,8 +41,87 @@ function blower_top(type)         = type[14]; //! Thickness of the top
 function blower_wall(type)        = type[15]; //! Side wall thickness
 function blower_lug(type)         = type[16]; //! Height of the lugs
 
+function blower_casing_is_square(type) = len(blower_screw_holes(type)) > 3; //! True for square radial fans, false for spiral shape radial blowers
+function blower_exit_offset(type) = blower_casing_is_square(type) ? blower_length(type) / 2 : blower_exit(type) / 2; //! Offset of exit's centre from the edge
+
 fan_colour = grey(20);
 
+module blower_fan(type, casing_is_square) {
+    module squarish(s, n) {
+        polygon([
+            for(i = [0 : n]) [i * s.x / n,  s.y + (i % 2) * eps],
+            for(i = [0 : n]) [s.x - i * s.x / n, (i % 2) * eps],
+        ]);
+    }
+
+    depth = blower_depth(type);
+    blade_ir = blower_hub(type) / 2 + 0.5; // slight gap between main part of blades and hub
+    blade_len = casing_is_square
+        ? (blower_bore(type) - 1) / 2 - blade_ir // fan constrained by bore hole
+        : blower_width(type) - blower_axis(type).x- blower_wall(type) - blade_ir; // fan extends to casing
+    blade_thickness = 0.75;
+    blade_count = 25;
+
+    base_offset = 1;
+    translate([blower_axis(type).x, blower_axis(type).y, blower_base(type) + base_offset])
+        linear_extrude(blower_hub_height(type) - 0.5 - blower_base(type) - base_offset, center = false, convexity = 4, twist = -30, slices = round(depth / 2))
+            for(i = [0 : blade_count - 1])
+                rotate((360 * i) / blade_count)
+                    translate([blade_ir, -blade_thickness / 2])
+                        squarish([blade_len, blade_thickness], round(blade_len / 2));
+}
+
+module blower_square(type) { //! Draw a square blower
+    width = blower_width(type);
+    depth = blower_depth(type);
+    wall = blower_wall(type);
+    hole_pitch = (blower_screw_holes(type)[1].x - blower_screw_holes(type)[0].x) / 2;
+    corner_radius = width / 2 - hole_pitch;
+    corner_inset = (width - blower_exit(type)) / 2;
+
+    module square_inset_corners(remove_center = false)
+        difference() {
+            //overall outside
+                square([width, width], center = false);
+
+            if (remove_center) {
+                // cut out the inside, leaving the corners
+                translate([corner_inset + wall, -eps])
+                    square([width - 2 * (wall + corner_inset), width - wall + eps], center = false);
+
+                translate([wall, corner_inset + wall])
+                    square([width - 2 * wall, width - 2 * (wall + corner_inset)], center = false);
+            } else {
+                // cut out the bore for the fan
+                translate(blower_axis(type))
+                    circle(d = blower_bore(type));
+            }
+            // corner inset
+            translate([width / 2, width / 2])
+            for(i = [0 : 3])
+                rotate(i * 90)
+                    translate([-width / 2 - eps, -width/ 2 - eps])
+                        quadrant(corner_inset, corner_inset - corner_radius);
+        }
+
+    base_height = blower_base(type);
+    linear_extrude(base_height)
+        difference () {
+            rounded_square([width, width], corner_radius, center = false);
+
+            blower_hole_positions(type)
+                circle(d = blower_screw_hole(type));
+        }
+
+    translate_z(base_height)
+        linear_extrude(depth - base_height)
+            square_inset_corners(remove_center = true);
+
+    translate_z(depth - base_height)
+        linear_extrude(blower_top(type))
+            square_inset_corners();
+}
+
 module blower(type) { //! Draw specified blower
     length = blower_length(type);
     width = blower_width(type);
@@ -70,55 +151,63 @@ module blower(type) { //! Draw specified blower
 
     vitamin(str("blower(", type[0], "): ", type[1]));
 
+    is_square = blower_casing_is_square(type); // Description starts with square!
     color(fan_colour) {
-        // screw lugs
-        linear_extrude(blower_lug(type), center = false)
-            for(hole = blower_screw_holes(type))
-                difference() {
-                    hull() {
+        if (is_square) {
+            blower_square(type);
+        } else {
+            // screw lugs
+            linear_extrude(blower_lug(type), center = false)
+                for(hole = blower_screw_holes(type))
+                    difference() {
+                        hull() {
+                            translate(hole)
+                                circle(d = blower_screw_hole(type) + 2 * blower_wall(type));
+
+                            translate(blower_axis(type))
+                                circle(d = blower_screw_hole(type) + 2 * blower_wall(type) + 7);
+                        }
                         translate(hole)
-                            circle(d = blower_screw_hole(type) + 2 * blower_wall(type));
+                            circle(d = blower_screw_hole(type));
 
-                        translate(blower_axis(type))
-                            circle(d = blower_screw_hole(type) + 2 * blower_wall(type) + 7);
-                    }
-                    translate(hole)
-                        circle(d = blower_screw_hole(type));
+                        shape(true);
+                }
 
-                    shape(true);
-               }
-        // rotor
-        translate(concat(blower_axis(type), [blower_base(type) + 1]))
-            rounded_cylinder(r = blower_hub(type) / 2, h = blower_hub_height(type) - blower_base(type) - 1, r2 = 1);
+            *%square([length, width]);
 
-        *%square([length, width]);
-
-        // base
-        linear_extrude(blower_base(type))
-            difference() {
-                shape();
-
-                translate(concat(blower_axis(type), [blower_base(type)]))
-                    circle(d = 2);
-           }
-        // sides
-        linear_extrude(depth)
-            difference() {
-                shape();
-
-                offset(-blower_wall(type))
-                    shape(true);
-           }
-
-        // top
-        translate_z(depth -blower_top(type))
-            linear_extrude(blower_top(type))
+            // base
+            linear_extrude(blower_base(type))
                 difference() {
                     shape();
 
                     translate(concat(blower_axis(type), [blower_base(type)]))
-                        circle(d = blower_bore(type));
-               }
+                        circle(d = 2);
+            }
+
+            // sides
+            linear_extrude(depth)
+                difference() {
+                    shape();
+
+                    offset(-blower_wall(type))
+                        shape(true);
+            }
+
+            // top
+            translate_z(depth -blower_top(type))
+                linear_extrude(blower_top(type))
+                    difference() {
+                        shape();
+
+                        translate(concat(blower_axis(type), [blower_base(type)]))
+                            circle(d = blower_bore(type));
+                }
+        }
+        // rotor
+        translate(concat(blower_axis(type), [blower_base(type) + 1]))
+            rounded_cylinder(r = blower_hub(type) / 2, h = blower_hub_height(type) - blower_base(type) - 1, r2 = 1);
+
+        blower_fan(type, is_square);
     }
 }
 

vitamins/blowers.scad

@@ -16,10 +16,16 @@
 // You should have received a copy of the GNU General Public License along with NopSCADlib.
 // If not, see <https://www.gnu.org/licenses/>.
 //
+//                                                   l     w   d   b     s              h   a            s    s                               e    h    b    t    w    l
+//                                                   e     i   e   o     c              u   x            c    c                               x    u    a    o    a    u
+//                                                   n     d   p   r     r              b   i            r    r                               i    b    s    p    l    g
+//                                                   g     t   t   e     e                  s            e    e                               t         e         l
+//                                                   t     h   h         w              d                w    w                                              t
+//                                                   h                                                  h    s                                         t         t
+RB5015 = ["RB5015", "Blower Runda RB5015",           51.3, 51, 15, 31.5, M4_cap_screw, 26, [27.3, 25.4], 4.5, [[4.3, 45.4], [47.3,7.4]],     20,   14,  1.5, 1.3, 1.2, 15];
+PE4020 = ["PE4020", "Blower Pengda Technology 4020", 40,   40, 20, 27.5, M3_cap_screw, 22, [21.5, 20  ], 3.2, [[37,3],[3,37],[37,37]],       29.3, 17,  1.7, 1.2, 1.3, 13];
+BL40x10 =["BL40x10","Square radial 4010",            40,   40,9.5, 27,   M2_cap_screw, 16, [24,   20  ], 2.4, [[2,2],[38,2],[2,38],[38,38]], 30  , 9.5, 1.5, 1.5, 1.1, 1.5];
 
-RB5015 = ["RB5015", "Blower Runda RB5015",           51.3, 51, 15, 31.5, M4_cap_screw, 26, [27.3, 25.4], 4.5, [[4.3, 45.4], [47.3,7.4]], 20, 14, 1.5, 1.3, 1.2, 15];
-PE4020 = ["PE4020", "Blower Pengda Technology 4020", 40,   40, 20, 27.5, M3_cap_screw, 22, [21.5, 20  ], 3.2, [[37,3],[3,37],[37,37]], 29.3, 17, 1.7, 1.2, 1.3, 13];
-
-blowers = [PE4020, RB5015];
+blowers = [BL40x10, PE4020, RB5015];
 
 use <blower.scad>