automatically calculate knob bore length

1 files changed, 2 insertions, 1 deletions

diff --git a/another.scad b/another.scad
index e4d79f9..915b184 100644
--- a/another.scad
+++ b/another.scad
@@ -8,51 +8,51 @@ 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 = pulley_e3d,
  pulley_elevation = 1,				// pulley elevation above the protrusion
  // idler properties
  idler_d = 10, 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,
+ knob_v_clearance = 1,
  // 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_metal,
  pf_shell = max(3*layer_height,3*extrusion_width),
 
  // empty spaces
  idler_travel = 3,				// how far should idler travel when pressed
  idler_clearance=.5,
  pulley_small_d_clearance=.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,
@@ -387,48 +387,49 @@ module the_extruder(
   h = hf*3.5;
   translate([-gearbox_d/2+st_thickshell+st_nut_h+st_nut_h_tolerance+st_thinshell+1,-longwing,filament_elevation])
   rotate([0,90,0]) difference() {
    union() {
     cylinder(d1=smalld,d2=bigd,h=hf,$fn=fnd*bigd);
     translate([0,0,hf-epsilon])
     cylinder(d=bigd,h=h-hf,$fn=fnd*bigd);
     translate([0,0,h])
     sphere(d=spring_d*3/4,$fn=fnd*spring_d*3/4);
     l = body_h-ls_z;
     w = st_split_w;
     hull() translate([0,-st_split_w/2,0]) mirror([1,0,0]) {
      translate([0,0,w])
      cube(size=[l,st_split_w,w]);
      cube(size=[l-w,st_split_w,2*w]);
     }
    }
    translate([0,0,-epsilon])
    cylinder(d=st_screw_d+st_screw_d_tolerance,h=2*hf+epsilon,$fn=fnd*(st_screw_d+st_screw_d_tolerance));
   }
  }
 
  module knob() {
   ch = knob_indent_d/2;
+  knob_bore_l = body_h-protrusion_h-pulley_elevation-pulley_h-knob_v_clearance;
   translate([0,0,body_h+epsilon]) {
    mirror([0,0,1]) translate([0,0,-epsilon]) {
     difference() {
      cylinder(d=pulley_d,h=knob_bore_l,$fn=fnd*pulley_d);
      translate([0,0,-1]) difference() {
       cylinder(d=bore_d+knob_bore_d_tolerance,h=knob_bore_l+2);
       translate([-bore_d/2-1,bore_dd-bore_d/2+knob_bore_d_tolerance/2,-1])
       cube([bore_d+2,bore_d/2,knob_bore_l+4]);
      }
     }
    }
    difference() {
     union() {
      cylinder(d1=gearbox_d-2*ch,d2=gearbox_d,h=ch+epsilon,$fn=fnd*gearbox_d);
      translate([0,0,ch])
      cylinder(d=gearbox_d,h=knob_h-2*ch+epsilon,$fn=fnd*gearbox_d);
      translate([0,0,knob_h-ch])
      cylinder(d1=gearbox_d,d2=gearbox_d-2*ch,h=ch,$fn=fnd*gearbox_d);
     }
     for(a=[0:360/knob_indents:359]) rotate([0,0,a])
      translate([0,gearbox_d/2,-1])
      cylinder(d=knob_indent_d,h=knob_h+2,$fn=fnd*knob_indent_d);
    }
   }