reworked empty space, tighter filament path

forgot a lot of what I've done anyway

1 files changed, 18 insertions, 26 deletions

diff --git a/another.scad b/another.scad
index 74b7ffa..78d4320 100644
--- a/another.scad
+++ b/another.scad
@@ -7,96 +7,97 @@ use <pushfittery.scad>;
 include <pushfit_data.scad>;
 
 module the_extruder(
  // motor properties
  gearbox_d = 36,
  mount_d = 28,					// the distance between opposite mounting holes
  mounthole_depth = 5,
  mounthole_min_depth = 3, mounthole_max_depth = 4,
  protrusion_d = 22, protrusion_h = 2.2,		// the dimensions of the protrusion on top of gearbox
  bore_d = 8, bore_l = 17.6,
  bore_dd = 7,
  // pulley properties
  pulley_d = 11.5, pulley_h=10,
  pulley_elevation = 1,				// pulley elevation above the protrusion
  teeth_elevation = 7.5,				// distance from the bottom of the pulley to its teeth
  filament_offset = (8.25-(3.0+3.5)/2) - 11.5/2 + 1.75/2,
  // idler properties
  idler_d = 9.5, idler_h = 4, idler_id = 3,	// idler dimensions: outer and inner diameters and height
  // spring properties
  spring_d = 10, spring_lc = 9.6,		// spring diameter and compressed length
  // filament path properties
  filament_d = 1.75,
  filament_path_d = 2,
  filament_guide_d = 4,				// PTFE filament guide diameter
  // knob properties
  knob_h = 10,
  knob_bore_l = 4,
  knob_indent_d = 4,
  knob_indents = 12,
  // spring tensioner
  st_nut_d = 9, st_nut_h = 4,
  st_screw_d = 5,
  st_thickshell = 8*extrusion_width, st_thinshell = 4*extrusion_width,
 
  // screw it
  mount_screw_d = 3.1, mount_screw_l = 20,
  mount_screwhead_d=6, mount_screwhead_h=3,
  idler_screw_d = 3,
  idler_screwhead_d=6, idler_screwhead_h=3,
 
  pf = pushfit_embeddest,
  pf_shell = max(3*layer_height,3*extrusion_width),
  pf_smooth = true,
 
  // empty spaces
  idler_travel = 3,				// how far should idler travel when pressed
  idler_clearance=1,
  pulley_d_clearance=2,
+ pulley_small_d_clearance=0.5,
  lever_v_clearance=.7,				// vertical clearance for the lever
  spring_d_clearance=1,
  protrusion_tolerance_h=.5,			// horizontal tolerance for the motor protrusion
  protrusion_tolerance_v=.5,			// vertical tolerance for the motor protrusion
  mount_screw_d_tolerance=.4,
  idler_v_tolerance=.5,
  knob_bore_d_tolerance=.6,
  st_nut_h_tolerance=.2,
  st_nut_d_tolerance=.2,/* TODO: make it st_nut_w_tolerance */
  st_screw_d_tolerance=.5,
  st_split_w_tolerance = .3,
 
  min_z_shell = 4*layer_height,                  // the very minimal shell thickness along z-axis.
  min_xy_shell = 2*extrusion_width,
 
  what="lever",  // lever|body|knob|springpad|*
  left=false,
  vitamins = true,
  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;
  shortwing = let(a=mount_d/2,c=(pulley_d+idler_d)/2/sqrt(2))
              sqrt(c*c+pow(a-c,2));
  longwing_travel = idler_travel*longwing/shortwing;
  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;
  // finger and spring support
  fsw = gearbox_d-(gearbox_d-mount_d)/2-max(spring_lc,longwing_travel+(gearbox_d-mount_d)/2);
 
  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) {
@@ -282,130 +283,121 @@ module the_extruder(
       hull() {
        cylinder(d=pfbd,h=pfbl,$fn=pfbd*fnd);
        translate([-epsilon/2,0,0]) {
         cube(size=[epsilon,filament_elevation,pfbl-filament_elevation+pfbd/2]);
         mirror([0,1,0])
         cube(size=[epsilon,body_h-filament_elevation,pfbl-body_h+filament_elevation+pfbd/2]);
        }//translate
       }//hull
      }else{
       pfb2a = pf_d(pf)+2*pf_shell; pfba = pfb2a/2;
       pfbd = pfb2a/cos(30);
       pfbs = pfb2a*tan(30);
       cylinder(d=pfbd,h=pfbl,$fn=6);
       translate([-pfbs/2,0,0]) {
        hull() {
         translate([0,-pfba,0]) cube(size=[pfbs,pfb2a,pfbl]);
         cube(size=[pfbs,filament_elevation,pfbl-filament_elevation+pfba]);
         mirror([0,1,0])
         cube(size=[pfbs,body_h-filament_elevation,pfbl-body_h+filament_elevation+pfba]);
        }//hull
       }//translate*/
      }//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
    pf_offset = mount_d/sqrt(2)/2+mount_screw_d;
    translate([0,0,filament_elevation])
    rotate([0,0,45]) translate([pulley_d/2+filament_offset,0,0])
    rotate([-90,0,0])
    translate([0,0,pf_offset])
    rotate([0,0,180]) {
     pushfit(pf);
     mirror([0,0,1]) {
      fh = 1.5* (filament_guide_d-filament_path_d)/2;
-     fo = pf_offset-(idler_d+idler_clearance)/2-fh;
-     translate([0,0,-1]) teardrop(d=filament_guide_d,h=fo-extrusion_width+1,angle=225);
+     fo = pf_offset -filament_path_d /*(idler_d+idler_clearance)/2*/-fh;
+     translate([0,0,-1]) teardrop(d=filament_guide_d,h=fo/2,angle=225);
      translate([0,0,-1]) teardrop(d=filament_path_d,h=gearbox_d/2+1,angle=-225);
      translate([0,0,fo+epsilon])
      cylinder(d1=filament_path_d,d2=filament_guide_d,h=fh,$fn=fnd*filament_guide_d);
     }//mirror
    }//rotate translate rotate translate rotate translate
    // pulley
-   cylinder(d=pulley_d+pulley_d_clearance,h=body_h+1,$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,$fn=fnd*(idler_d+idler_clearance));
-
-   // idler clearance
-   a=cos(45)*(pulley_d+idler_d)/2;
-   b=mount_d/2-a;
-   x=sqrt(pow(a,2)+pow(b,2));
-   translate([mount_d/2,0,ls_z])
-   intersection() {
-    r = x+idler_d/2+idler_clearance;
-    cylinder(r=r,h=ls_h,center=true);
-    translate([-r-1,0,-ls_h/2-1]) cube(size=[2*r+2,r+1,ls_h+2]);
-   }
+   cylinder(d=pulley_d+pulley_small_d_clearance,h=body_h+1,$fn=fnd*(pulley_d+pulley_d_clearance));
+   cylinder(d=pulley_d+pulley_d_clearance,ls_z-max(idler_h,filament_guide_d)/2,$fn=fnd*(pulley_d+pulley_d_clearance));
 
-   rotate([0,0,-45])
-   translate([0,0,ls_z-ls_h/2])
-   cube(size=[gearbox_d,gearbox_d,lever_thickness+lever_v_clearance]);
    translate([0,0,ls_z-ls_h/2]) {
-    translate([mount_screwhead_d/2,0,0])
-    mirror([0,1,0])
-    cube(size=[gearbox_d,gearbox_d/2+1,lever_thickness+lever_v_clearance]);
+    // idler travel
+    translate([mount_d/2,0,0])
+    rotate([0,0,45])
+    rotate_extrude(angle=90,$fn=fnr*(shortwing+(idler_d+idler_clearance)/2))
+    square([shortwing+(idler_d+idler_clearance)/2,ls_h]);
+    // idler itself
+    place_idler()
+    cylinder(d=idler_d+idler_clearance,h=ls_h,$fn=fnd*(idler_d+idler_clearance));
+    // lever space
+    echo(atan(1-2*fsw/gearbox_d));
+    rotate([0,0,45])
+    rotate_extrude(angle=-135+max(atan(2*fsw/gearbox_d-1),atan(gearbox_d/mount_d-1)))
+    square([gearbox_d/2+1,ls_h]);
    }
 
    // back side cutout
    // XXX: this is somewhat ugly and potentially bugged,
    //      but I want to sleep.
    a0_ = atan(
     (mount_d/sqrt(2)/2+mount_screw_d+pf_h(pf)+gearbox_d/2)
     /
     (
      pulley_d/2+filament_offset-
      (pf_d(pf)+2*pf_shell)/2/cos(30)
     )
    );
    a0 = -135 + ( (a0_>0) ? a0_ : 180+a0_ );
    a1 = atan((longwing-lever_thickness/2)/(gearbox_d/2));
    translate([0,0,ls_z]) difference() {
     rotate([0,0,-180+a0])
     rotate_extrude(angle=a1-a0)
     translate([0,-ls_h/2])
     square([sqrt(pow(gearbox_d/2,2)+pow(longwing-lever_thickness/2,2))+1,
            ls_h]);
     translate([-mount_d/2,0,0])
     cylinder(d=gearbox_d-mount_d,h=ls_h+2,center=true,$fn=fnd*(gearbox_d-mount_d));
    }//difference translate
    
    //translate([-mount_d/2,-longwing,filament_elevation])
    if(!tensioner) /* XXX: this seems to be bullshit, but it's so old, that it's historical bullshit */
    translate([mount_d/2,-longwing,filament_elevation])
    rotate([0,-90,0]) difference() {
     cylinder(d=spring_d+spring_d_clearance,h=spring_lc+spring_dl,$fn=fnd*(spring_d+spring_d_clearance));
     translate([0,0,spring_lc+spring_dl]) sphere(d=spring_d*3/4,$fn=fnd*spring_d*3/4);
    }
 
   }//difference
 
   if(supports) intersection() {
    difference() {
     translate([0,0,ls_z-ls_h/2-epsilon])
     cylinder(d=gearbox_d,h=ls_h+2*epsilon,$fn=fnd*gearbox_d);
     cylinder(d=pulley_d+pulley_d_clearance,h=body_h+1,$fn=fnd*(pulley_d+pulley_d_clearance));
    }
    // supports
    // TODO: hardcoded stuff below…
    if(false) { // parallel
     for(y=[-gearbox_d:4:gearbox_d])
      translate([0,y-extrusion_width/2,0])
      cube(size=[gearbox_d,extrusion_width,body_h]);
    }else{ // radial