another: lookup-driven filament drive puley specification

2 files changed, 16 insertions, 4 deletions

diff --git a/another.scad b/another.scad
index ed18874..51358ee 100644
--- a/another.scad
+++ b/another.scad
@@ -1,128 +1,132 @@
 draft=true;
 layer_height=0.2; extrusion_width=0.4;
 epsilon=0.01;
 $fs=0.0125;
 
 use <pushfittery.scad>;
 include <pushfit_data.scad>;
+include <pulley_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 = pulley_e3d,
          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 = 2*extrusion_width,
  st_split_w = 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,
  bridges = true,
  debug = false,
  label = "another"
 ) {
  fnd = 2*PI; fnr = 2*fnd;
+ function lu(m,k) = m[search([k],m)[0]][1];
 
+ pulley_d = lu(pulley,"d");
+ pulley_h = lu(pulley,"h");
+ teeth_elevation = lu(pulley,"fe");
+ filament_offset = lu(pulley,"g")+filament_d/2;
+ pulley_d_clearance = lu(pulley,"ssrc")*2;
  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; // the diameter of lever thingie
  longwing=(mount_d+mount_screw_d+mount_screw_d_tolerance+spring_d+spring_d_clearance)/2+min_xy_shell;
  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) {
   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);
diff --git a/pulley_data.scad b/pulley_data.scad
new file mode 100644
index 0000000..a1523de
--- a/dev/null
+++ b/pulley_data.scad
@@ -0,0 +1,8 @@
+pulley_e3d = [
+         ["d", 11.5 ],          // outer diameter
+         ["h", 11 ],            // pulley height
+         ["g", 8.25-3 - 11.5/2 ],// depth of U-groove, filament offset from the surface
+         ["fe", 7.5 ],          // filament elevation from the bottom
+         ["ssrc", 2 ],          // set screw radial clearance
+];
+