Thickness Fixes (+ 3.0 default) (#93)

This PR fixes a few issues relating to panel thickness:

 - Spool width now accounts for flap width. If the calculated spool width is smaller than the flap width, the enclosure width and front opening do not shrink further. This also comments out the legacyAssert for spool width which is no longer needed.
- Flap notch height and depth are now static and reflect the die-cut flap dimensions. The flap height can be set back to auto with the flap_notch_height_auto flag.
- Enclosure side bolts are now positioned properly for all thicknesses
- The enclosure vertical inset (distance between top/bottom of front and top/bottom pieces) now has a minimum value to prevent the bolt heads and nut edges from extending past the bounds of the enclosure at thinner thicknesses
- Sets the default thickness to 3.0, matching Ponoko's current MDF availability. Tentatively closes #76

Author: dmadison

3d/flap_dimensions.scad

@@ -19,5 +19,9 @@ flap_height = 43;
 flap_thickness = 30 / 1000 * 25.4; // 30 mil
 flap_corner_radius = 3.1; // 2.88-3.48mm (used just for display)
 
+flap_notch_height_auto = false;
+flap_notch_height_default = 15;
+flap_notch_depth = 3.2;
+
 flap_pin_width = 1.4;
 

3d/splitflap.scad

@@ -67,13 +67,13 @@ spool_horizontal_explosion = lookup(spool_explosion, [
 ]);
 
 
-// Kerf based off http://blog.ponoko.com/2011/07/12/figuring-out-kerf-for-precision-parts/
-// It's better to underestimate (looser fit) than overestimate (no fit)
-kerf_width = 0.19 - 0.02;
+// Ponoko kerf values are 0.2 mm for MDF and acrylic (all thicknesses)
+// Remember: it's better to underestimate (looser fit) than overestimate (no fit)
+kerf_width = 0.2 - 0.02;
 
-// MDF, .125in nominal
-// http://www.ponoko.com/make-and-sell/show-material/64-mdf-natural
-thickness = 3.2;
+// MDF, .120in nominal
+// https://www.ponoko.com/materials/mdf-fiberboard
+thickness = 3.0;
 
 eps=.01;
 
@@ -90,10 +90,12 @@ assembly_color4 = [.204, .161, .114]; //"34291D";
 flap_rendered_angle = 90;
 
 // Amount of slop of the flap side to side between the 2 spools
-flap_width_slop = 0.1;
+flap_width_slop = 0.5;
 
 // Amount of slop for the spool assembly side-to-side inside the enclosure
 spool_width_slop = 1;
+spool_tab_clearance = 0.10;
+spool_joint_clearance = 0.10;
 
 
 num_flaps = 40;
@@ -114,13 +116,13 @@ outer_exclusion_radius = flap_pitch_radius + flap_height + 2;
 
 front_forward_offset = flap_pitch_radius + flap_thickness/2;
 
-flap_notch = sqrt(spool_outer_radius*spool_outer_radius - flap_pitch_radius*flap_pitch_radius);
-flap_notch_depth = 3;
+flap_notch_height = (flap_notch_height_auto == true) ? sqrt(spool_outer_radius*spool_outer_radius - flap_pitch_radius*flap_pitch_radius) : flap_notch_height_default;
 
+spool_width = flap_width - flap_notch_depth*2 + flap_width_slop + thickness*2;  // spool width, outside face (spool to spool)
+spool_width_clearance = max(spool_width, flap_width + flap_width_slop);  // width clearance for the spool, either for the spool itself or the flaps
 
-spool_width = flap_width - flap_notch_depth*2 + flap_width_slop + thickness*2;
-legacyAssert(spool_width >= flap_width, "Flap is wider than spool!");
-spool_strut_tabs = 3;
+//legacyAssert(spool_width >= flap_width, "Flap is wider than spool!");
+spool_strut_num_joints = 3;
 spool_strut_tab_width=8;
 spool_strut_tab_width_narrow=6;
 spool_strut_tab_outset=8;
@@ -141,7 +143,7 @@ motor_slop_radius = 3;
 
 
 // Width measured from the outside of the walls
-enclosure_wall_to_wall_width = thickness + spool_width_slop/2 + spool_width + spool_width_slop/2 + max(28byj48_mount_bracket_height + m4_button_head_length, 4 + 28byj48_mount_bracket_height - spool_width_slop/2) + thickness;
+enclosure_wall_to_wall_width = thickness + spool_width_slop/2 + spool_width_clearance + spool_width_slop/2 + max(28byj48_mount_bracket_height + m4_button_head_length, 4 + 28byj48_mount_bracket_height - spool_width_slop/2) + thickness;
 
 // Width of the front panel
 enclosure_width = enclosure_wall_to_wall_width + 28byj48_chassis_height + 28byj48_chassis_height_slop - thickness - 28byj48_mount_bracket_height;
@@ -151,10 +153,10 @@ front_window_overhang = 3;
 front_window_upper = front_window_upper_base - front_window_overhang;
 front_window_lower = sqrt(outer_exclusion_radius*outer_exclusion_radius - front_forward_offset*front_forward_offset);
 front_window_slop = 0;
-front_window_width = spool_width_slop + spool_width + front_window_slop;
+front_window_width = spool_width_slop + spool_width_clearance + front_window_slop;
 front_window_right_inset = thickness - front_window_slop/2;
 enclosure_vertical_margin = 10; // gap between top/bottom of flaps and top/bottom of enclosure
-enclosure_vertical_inset = thickness*1.5; // distance from top of sides to top of the top piece
+enclosure_vertical_inset = max(thickness*1.5, m4_nut_width_corners_padded/2); // distance from top of sides to top of the top piece
 enclosure_height_upper = exclusion_radius + enclosure_vertical_margin + thickness + enclosure_vertical_inset;
 enclosure_height_lower = flap_pitch_radius + flap_height + enclosure_vertical_margin + thickness + enclosure_vertical_inset;
 enclosure_height = enclosure_height_upper + enclosure_height_lower;
@@ -165,6 +167,8 @@ enclosure_length = front_forward_offset + 28byj48_mount_center_offset + m4_hole_
 
 
 // Enclosure tabs: front/back
+enclosure_tab_clearance = 0.10;
+
 num_front_tabs = 2;
 front_tab_width = (enclosure_wall_to_wall_width - 2*thickness) / (num_front_tabs*2 - 1);
 
@@ -187,6 +191,8 @@ connector_bracket_length_inner = side_tab_width * 2 - m4_button_head_diameter/2;
 connector_bracket_thickness = captive_nut_inset - thickness - 0.2;
 connector_bracket_width = enclosure_width - enclosure_wall_to_wall_width + thickness*2 + connector_bracket_thickness*2;
 connector_bracket_overlap = 4;
+connector_bracket_clearance = 0.10;
+connector_bracket_depth_clearance = 0.20;
 
 
 mounting_hole_inset = m4_button_head_diameter/2 + 2;
@@ -208,7 +214,7 @@ echo(front_window_height=front_window_lower+front_window_upper);
 echo(front_forward_offset=front_forward_offset);
 echo(flap_exclusion_radius=exclusion_radius);
 echo(flap_hole_radius=flap_hole_radius);
-echo(flap_notch=flap_notch);
+echo(flap_notch_height=flap_notch_height);
 
 
 module standard_m4_bolt(nut_distance=-1) {
@@ -248,7 +254,7 @@ module m4_captive_nut(bolt_length=m4_bolt_length) {
 
 // ##### Struts for bracing spool #####
 module spool_strut_tab_hole(narrow) {
-    square([thickness, narrow ? spool_strut_tab_width_narrow : spool_strut_tab_width], center=true);
+    square([thickness + spool_tab_clearance, narrow ? spool_strut_tab_width_narrow + spool_tab_clearance : spool_strut_tab_width + spool_tab_clearance], center=true);
 }
 module spool_strut_tab_holes(narrow=false) {
     for (i=[0:3]) {
@@ -259,7 +265,7 @@ module spool_strut_tab_holes(narrow=false) {
     }
 }
 module spool_strut() {
-    joint_tab_width = spool_strut_inner_length / spool_strut_tabs;
+    joint_tab_width = spool_strut_inner_length / spool_strut_num_joints;
     linear_extrude(thickness, center=true) {
         union() {
             translate([0, -spool_strut_tab_width_narrow / 2]) {
@@ -272,15 +278,15 @@ module spool_strut() {
                 difference() {
                     square([spool_strut_inner_length, spool_strut_width]);
 
-                    // subtract out tabs
+                    // subtract out joints
                     union() {
-                        for (i = [0:2:spool_strut_tabs-1]) {
-                            translate([i*joint_tab_width, -eps])
-                                square([joint_tab_width, thickness+eps]);
+                        for (i = [0:2:spool_strut_num_joints-1]) {
+                            translate([i*joint_tab_width - spool_joint_clearance/2, -eps])
+                                square([joint_tab_width + spool_joint_clearance, thickness + spool_joint_clearance/2 + eps]);
                         }
-                        for (i = [1:2:spool_strut_tabs-1]) {
-                            translate([i*joint_tab_width, spool_strut_width - thickness])
-                                square([joint_tab_width, thickness+eps]);
+                        for (i = [1:2:spool_strut_num_joints-1]) {
+                            translate([i*joint_tab_width, spool_strut_width - thickness - spool_joint_clearance/2])
+                                square([joint_tab_width, thickness + spool_joint_clearance + eps]);
                         }
                     }
                 }
@@ -354,9 +360,9 @@ module flap_2d() {
             }
         }
         translate([-eps, flap_pin_width])
-            square([eps + flap_notch_depth, flap_notch]);
+            square([eps + flap_notch_depth, flap_notch_height]);
         translate([flap_width - flap_notch_depth, flap_pin_width])
-            square([eps + flap_notch_depth, flap_notch]);
+            square([eps + flap_notch_depth, flap_notch_height]);
     }
 }
 
@@ -412,7 +418,7 @@ module motor_shaft() {
 module front_tabs_negative() {
     for (i = [0 : num_front_tabs-1]) {
         translate([thickness + (i*2+0.5) * front_tab_width, 0, 0])
-            square([front_tab_width, thickness], center=true);
+            square([front_tab_width + enclosure_tab_clearance, thickness + enclosure_tab_clearance], center=true);
     }
     for (i = [0 : num_front_tabs-2]) {
         translate([thickness + (i*2+1.5) * front_tab_width, 0, 0])
@@ -427,11 +433,11 @@ module connector_bracket() {
             translate([connector_bracket_thickness, -eps]) {
                 square([connector_bracket_width - connector_bracket_thickness*2, connector_bracket_length_outer - connector_bracket_length_inner + eps]);
             }
-            translate([connector_bracket_thickness, -eps]) {
-                square([thickness, connector_bracket_length_outer - connector_bracket_overlap + eps]);
+            translate([connector_bracket_thickness - connector_bracket_clearance/2, -eps]) {
+                square([thickness + connector_bracket_clearance, connector_bracket_length_outer - connector_bracket_overlap + connector_bracket_depth_clearance + eps]);
             }
-            translate([connector_bracket_width - connector_bracket_thickness - thickness, -eps]) {
-                square([thickness, connector_bracket_length_outer - connector_bracket_overlap + eps]);
+            translate([connector_bracket_width - connector_bracket_thickness - thickness - connector_bracket_clearance/2, -eps]) {
+                square([thickness + connector_bracket_clearance, connector_bracket_length_outer - connector_bracket_overlap + connector_bracket_depth_clearance + eps]);
             }
         }
     }
@@ -484,8 +490,8 @@ module motor_mount() {
 module side_tabs_negative(hole_sizes=[], extend_last_tab=false) {
     for (i = [0 : len(hole_sizes)]) {
         length = (extend_last_tab && i == len(hole_sizes)) ? side_tab_width * side_tab_width_fraction + eps : side_tab_width * side_tab_width_fraction;
-        translate([-thickness / 2, thickness + (i*2) * side_tab_width + side_tab_width * (1 - side_tab_width_fraction)/2, 0])
-            square([thickness, length]);
+        translate([0,  thickness + (i*2) * side_tab_width + side_tab_width * (1 - side_tab_width_fraction)/2 + length/2, 0])
+            square([thickness + enclosure_tab_clearance, length + enclosure_tab_clearance], center=true);
     }
     for (i = [0 : len(hole_sizes) - 1]) {
         hole_size = hole_sizes[i];
@@ -508,8 +514,8 @@ module backstop_bolt_slot(radius) {
 
 module connector_bracket_side_holes() {
     // overlap slot
-    translate([enclosure_vertical_inset - thickness, -connector_bracket_overlap]) {
-        square([thickness, connector_bracket_overlap + eps]);
+    translate([enclosure_vertical_inset - thickness - connector_bracket_clearance/2, -connector_bracket_overlap]) {
+        square([thickness + connector_bracket_clearance, connector_bracket_overlap + eps]);
     }
 }
 
@@ -792,14 +798,14 @@ module split_flap_3d(letter, include_connector) {
 
     module positioned_left_bolts() {
         // Top
-        translate([enclosure_wall_to_wall_width, front_forward_offset - side_tab_width * 2, enclosure_height_upper - enclosure_vertical_inset - thickness/2]) {
+        translate([enclosure_wall_to_wall_width, front_forward_offset - (thickness + 1.5 * side_tab_width), enclosure_height_upper - enclosure_vertical_inset - thickness/2]) {
             rotate([0, -90, 0]) {
                 standard_m4_bolt(nut_distance=captive_nut_inset);
             }
         }
 
         // Bottom
-        translate([enclosure_wall_to_wall_width, front_forward_offset - side_tab_width * 2, -enclosure_height_lower + enclosure_vertical_inset + thickness/2]) {
+        translate([enclosure_wall_to_wall_width, front_forward_offset - (thickness + 1.5 * side_tab_width), -enclosure_height_lower + enclosure_vertical_inset + thickness/2]) {
             rotate([0, -90, 0]) {
                 standard_m4_bolt(nut_distance=captive_nut_inset);
             }
@@ -808,14 +814,14 @@ module split_flap_3d(letter, include_connector) {
 
     module positioned_right_bolts() {
         // Top
-        translate([0, front_forward_offset - side_tab_width * 2, enclosure_height_upper - enclosure_vertical_inset - thickness/2]) {
+        translate([0, front_forward_offset - (thickness + 1.5 * side_tab_width), enclosure_height_upper - enclosure_vertical_inset - thickness/2]) {
             rotate([0, 90, 0]) {
                 standard_m4_bolt(nut_distance=captive_nut_inset);
             }
         }
 
         // Bottom
-        translate([0, front_forward_offset - side_tab_width * 2, -enclosure_height_lower + enclosure_vertical_inset + thickness/2]) {
+        translate([0, front_forward_offset - (thickness + 1.5 * side_tab_width), -enclosure_height_lower + enclosure_vertical_inset + thickness/2]) {
             rotate([0, 90, 0]) {
                 standard_m4_bolt(nut_distance=captive_nut_inset);
             }
@@ -911,7 +917,8 @@ module split_flap_3d(letter, include_connector) {
                 }
             }
 
-            translate([-flap_notch_depth + thickness + flap_width_slop/2, 0, 0]) {
+            flap_offset = thickness > flap_notch_depth ? -flap_notch_depth + thickness + flap_width_slop/2 : flap_width_slop/2;
+            translate([flap_offset, 0, 0]) {
                 // Collapsed flaps on the top
                 for (i=[0:num_flaps/2 - 1]) {
                     if (i == 0 || render_flaps == 2) {
@@ -944,8 +951,10 @@ module split_flap_3d(letter, include_connector) {
                 }
             }
         }
+    }
 
-        if(render_spool) {
+    if(render_spool) {
+        translate([(spool_width_clearance - spool_width + spool_width_slop) / 2 + thickness, 0, 0]) {
             spool_struts();
 
             // motor spool