teardrop module

1 files changed, 18 insertions, 15 deletions

diff --git a/another.scad b/another.scad
index f4e8904..23243d9 100644
--- a/another.scad
+++ b/another.scad
@@ -71,48 +71,57 @@ module the_extruder(
  supports = false, bridges = true,
  tensioner = true,
  debug = false
 ) {
  fnd = 2*PI; fnr = 2*fnd;
 
  idler_filament_offset = filament_path_d/2; // -filament_offset;
  lever_shell = mount_screwhead_h+0.5;
  lever_thickness=max(spring_d+spring_d_clearance+layer_height*8,idler_h+idler_v_tolerance+2*lever_shell);
  lsd = idler_d-idler_clearance*2;
  longwing=gearbox_d/2+spring_d/2+lsd/2;
  h_ = (pulley_d+idler_d)/(2*sqrt(2));
  ri = sqrt( pow(h_,2) + pow(mount_d/2-h_,2) );
  spring_dl = idler_travel*longwing/ri;
 
  mount_min_depth = mounthole_min_depth ? mounthole_min_depth : mounthole_depth-1;
  mount_max_depth = mounthole_max_depth ? mounthole_max_depth : mounthole_depth+1;
  filament_elevation=protrusion_h+pulley_elevation+teeth_elevation;
  ls_z = filament_elevation; // leverspace mid-z
  ls_h = lever_thickness+lever_v_clearance; // leverspace height
  mount_depth = mount_screw_l - (ls_z+ls_h/2+min_z_shell);
  body_h = max(protrusion_h+bore_l,mount_screw_l-mount_depth+mount_screwhead_h+min_z_shell,ls_z*2);
  echo("mount depth",mount_depth);
 
+ module teardrop(r,d,h,center=false,angle=45) {
+  dd = d ? d : (2*r);
+  $fn = dd*fnd;
+  cylinder(d=dd,h=h,center=center);
+  if(angle>0) translate([0,0,center?-h/2:0])
+   rotate([0,0,angle])
+   cube(size=[d/2,d/2,h]);
+ }
+
  module mirrorleft() {
   mirror([left?0:1,0,0]) children();
  }
  module place_idler() {
   rotate([0,0,45])
   translate([(pulley_d+idler_d)/2,0,0])
   children();
  }
  module finger_indent(d=lever_thickness,depth/*=1*/,r/*=15*/) {
   if(depth) {
    hh = (-4*pow(depth,2)+pow(d,2))/(8*depth);
    rr = depth+hh;
    translate([0,0,hh]) sphere(r=rr,$fn=fnr*rr);
   }else if(r) {
    hh=sqrt(pow(r,2)-pow(d,2)/4);
    translate([0,0,hh]) sphere(r=r,$fn=fnr*r);
   }
  }
 
  % if(vitamins) mirrorleft() {
   translate([0,0,-epsilon]) mirror([0,0,1]) cylinder(d=gearbox_d,h=1,$fn=60);
   for(zr=[0:90:359]) rotate([0,0,zr]) translate([mount_d/2,0,0])
    cylinder(d=mount_screw_d,h=20,$fn=30);
   translate([0,0,-epsilon]) cylinder(d=protrusion_d,h=protrusion_h,$fn=30);
@@ -143,66 +152,63 @@ module the_extruder(
     }//translate teeth
    }//translate pulley
   }//translate protrusion
  }//vitamins
 
  module lever() {
   translate([0,0,protrusion_h+pulley_elevation+teeth_elevation]) {
    difference() {
     union() {
      hull() {
       place_idler()
       cylinder(d=lsd,h=lever_thickness,center=true,$fn=60);
       translate([mount_d/2,0,0])
       cylinder(d=lsd,h=lever_thickness,center=true,$fn=60);
      }//hull
      hull() {
       translate([mount_d/2,0,0])
       cylinder(d=lsd,h=lever_thickness,center=true,$fn=60);
       translate([mount_d/2,-longwing,0]) rotate([0,90,0])
       cylinder(d=lever_thickness,h=lsd,center=true,$fn=60);
      }//hull
     }//union
  
     // filament path
-    place_idler() {
-     translate([-idler_d/2-idler_filament_offset,0,0]) rotate([90,0,0]) {
-      cylinder(d=filament_path_d,h=3*gearbox_d,center=true,$fn=30);
-      translate([0,-filament_path_d/2/sqrt(2),0]) rotate([0,0,45])
-      cube(size=[filament_path_d/2,filament_path_d/2,3*gearbox_d],center=true);
-     }//rotate translate
-     translate([-idler_d/2-idler_filament_offset,0,0])
-     rotate([90,0,0])
+    place_idler()
+    translate([-idler_d/2-idler_filament_offset,0,0])
+    rotate([90,0,0]) {
+     mirror([0,1,0])
+     teardrop(d=filament_path_d,h=3*gearbox_d,center=true);
      translate([0,0,
       sqrt(2)*(mount_d-pulley_d+lsd)/2
      ]) {
       cylinder(d1=filament_path_d,d2=2*filament_path_d,
                h=filament_path_d,$fn=2*filament_path_d*fnd);
       translate([0,0,filament_path_d-epsilon])
       cylinder(d=2*filament_path_d,h=lsd,$fn=2*filament_path_d*fnd);
-     }
-    }//place_idler
-    
+     }//translate
+    }//rotate translate place_idler
+
     // idler space and mounting hole
     place_idler() {
      difference() {
       cylinder(d=idler_d+idler_clearance*2,h=idler_h+idler_v_tolerance,center=true,$fn=60);
       if(supports) for(y=[-lsd/2+extrusion_width:(lsd-2*extrusion_width)/3:lsd/2-extrusion_width])
        translate([-lsd/2-1,y-extrusion_width/2,-idler_h/2-idler_v_tolerance/2-1])
        cube(size=[lsd+2,extrusion_width,idler_h+idler_v_tolerance+2]);
      }
      cylinder(d=idler_screw_d,h=lever_thickness+2,center=true,$fn=30);
      translate([0,0,lever_thickness/2-idler_screwhead_h])
      cylinder(d=idler_screwhead_d,h=idler_screwhead_h+1,$fn=fnd*idler_screwhead_d);
     }
     // mounting screw hole
     translate([mount_d/2,0,0])
     cylinder(d=mount_screw_d+mount_screw_d_tolerance,h=lever_thickness+2,center=true,$fn=fnd*mount_screw_d);
     
     // lever end
     translate([mount_d/2,0,0]) rotate([0,90,0]) {
      translate([0,-longwing,lsd/2]) finger_indent(d=lever_thickness-1,r=15);
      translate([0,-longwing,0])
      mirror([0,0,1])
      difference() {
       cylinder(d=spring_d+spring_d_clearance,h=lsd,$fn=fnd*(spring_d+spring_d_clearance));
       sphere(d=spring_d*3/4,$fn=fnd*spring_d*3/4);
@@ -289,52 +295,49 @@ module the_extruder(
      }//if(pf_smooth)
     }//translate rotate translate rotate translate
    }//union (first child of difference)
 
    // protrusion
    translate([0,0,-1])
    cylinder(d=protrusion_d+protrusion_tolerance_h,h=protrusion_h+protrusion_tolerance_v+1,$fn=fnd*(protrusion_d+protrusion_tolerance_h));
    // mount screw holes
    for(zr=[0:90:359]) rotate([0,0,zr]) translate([mount_d/2,0,0]) {
     translate([0,0,mount_screw_l-mount_depth-(bridges?layer_height:-epsilon)])
     mirror([0,0,1])
     cylinder(d=mount_screw_d+mount_screw_d_tolerance,
              h=mount_screw_l-mount_depth+1,
              $fn=fnd*(mount_screw_d+mount_screw_d_tolerance));
     translate([0,0,mount_screw_l-mount_depth])
     cylinder(d=mount_screwhead_d,h=body_h+1,$fn=fnd*mount_screwhead_d);
    }//for
    // pushfit
    translate([0,0,filament_elevation])
    rotate([0,0,45]) translate([pulley_d/2+filament_offset,0,0])
    rotate([-90,0,0])
    translate([0,0,mount_d/sqrt(2)/2+mount_screw_d+epsilon])
    rotate([0,0,180]) {
     pushfit(pf);
-    cylinder(d=filament_guide_d,h=gearbox_d,center=true,$fn=fnd*filament_guide_d);
-    translate([0,-filament_guide_d/2/sqrt(2),0])
-    rotate([0,0,45])
-    cube(size=[filament_guide_d/2,filament_guide_d/2,gearbox_d],center=true);
+    mirror([0,1,0]) teardrop(d=filament_guide_d,h=gearbox_d,center=true);
    }//rotate translate rotate translate rotate translate
    // pulley
    cylinder(d=pulley_d+pulley_d_clearance,h=body_h+1,$fn=fnd*(pulley_d+pulley_d_clearance));
    // leverspace
    hull() for(x=[0,gearbox_d])
    rotate([0,0,45])
    translate([x,0,ls_z-ls_h/2])
    cylinder(d=idler_d+idler_clearance,h=ls_h,$fn=fnd*(idler_d+idler_clearance));
 
    // idler clearance
    a=cos(45)*(pulley_d+idler_d)/2;
    b=mount_d/2-a;
    x=sqrt(pow(a,2)+pow(b,2));
    translate([mount_d/2,0,ls_z])
    intersection() {
     r = x+idler_d/2+idler_clearance;
     cylinder(r=r,h=ls_h,center=true);
     translate([-r-1,0,-ls_h/2-1]) cube(size=[2*r+2,r+1,ls_h+2]);
    }
 
    // back side cutout
    // XXX: this is somewhat ugly and potentially bugged,
    //      but I want to sleep.
    a0_ = atan(