finetune filament offset relative to the pulley

1 files changed, 7 insertions, 6 deletions

diff --git a/another.scad b/another.scad
index b80d0d0..a93d21a 100644
--- a/another.scad
+++ b/another.scad
@@ -1,44 +1,45 @@
 draft=true;
 layer_height=0.2; extrusion_width=0.4;
 epsilon=0.01;
 $fs=0.0125;
 
 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,
          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,
 
@@ -100,85 +101,85 @@ module the_extruder(
    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,$fn=30);
   translate([0,0,protrusion_h]) {
    difference() {
     cylinder(d=bore_d,h=bore_l,$fn=30);
     translate([-bore_d/2-1,bore_dd-bore_d/2,-1])
     cube([bore_d+2,bore_d/2,bore_l+2]);
    }
    translate([0,0,pulley_elevation]) {
     cylinder(d=pulley_d,h=pulley_h,$fn=30);
     translate([0,0,teeth_elevation]) {
      place_idler() {
       cylinder(d=idler_d,h=idler_h,center=true,$fn=30);
       cylinder(d=idler_screw_d,h=lever_thickness+2,center=true,$fn=30);
      }//place idler
      // filament path
-     rotate([0,0,45]) translate([pulley_d/2,0,0]) {
+     rotate([0,0,45]) translate([pulley_d/2+filament_offset,0,0]) {
       rotate([90,0,0]) cylinder(d=filament_d,h=gearbox_d*2,center=true,$fn=15);
       rotate([-90,0,0])
       translate([0,0,mount_d/sqrt(2)/2+mount_screw_d])
       pushfit(pf);
      }
     }//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/2,0,0]) rotate([90,0,0]) {
+     translate([-idler_d/2+filament_offset,0,0]) rotate([90,0,0]) {
       cylinder(d=filament_path_d,h=3*gearbox_d,center=true,$fn=30);
       translate([0,-filament_path_d/2/sqrt(2),0]) rotate([0,0,45])
       cube(size=[filament_path_d/2,filament_path_d/2,3*gearbox_d],center=true);
      }//rotate translate
-     translate([-idler_d/2,0,0])
+     translate([-idler_d/2+filament_offset,0,0])
      rotate([90,0,0])
      translate([0,0,
       sqrt(2)*(mount_d-pulley_d+lsd)/2
      ]) {
       cylinder(d1=filament_path_d,d2=2*filament_path_d,
                h=filament_path_d,$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
     
     // 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,$fn=fnd*idler_screwhead_d);
     }
     // mounting screw hole
@@ -225,131 +226,131 @@ module the_extruder(
       }
      }
      translate([0,-longwing,ls_z]) rotate([0,-90,0]) {
       if(!tensioner) finger_indent(d=lever_thickness-1,r=15); else {
        mirror([0,0,1]) {
         translate([0,0,st_thickshell])
         hull() for(o=[0,spring_d]) translate([0,-o,0])
         rotate([0,0,30])
         cylinder(d=st_nut_d+st_nut_d_tolerance,h=st_nut_h+st_nut_h_tolerance,$fn=6);
         translate([0,0,-1]) cylinder(d=st_screw_d+st_screw_d_tolerance,h=fsw+2,$fn=fnd*(st_screw_d+st_screw_d_tolerance));
         bigd = spring_d+spring_d_clearance;
         hf = (bigd-st_screw_d-st_screw_d_tolerance)/2;
         translate([0,0,st_thickshell+st_nut_h+st_nut_h_tolerance+st_thinshell-epsilon])
         cylinder(d1=st_screw_d+st_screw_d_tolerance,d2=bigd,
          h=hf+epsilon, $fn=fnd*bigd);
         translate([0,0,st_thickshell+st_nut_h+st_nut_h_tolerance+st_thinshell+hf-epsilon])
         cylinder(d=bigd,h=fsw+1,$fn=fnd*bigd);
        }
       }
      }
     } // translate
     
     // pushfit bracket
     translate([0,0,filament_elevation])
-    rotate([0,0,45]) translate([pulley_d/2,0,0])
+    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-gearbox_d/2/*TODO:*/]) {
      pfbl = pf_h(pf)+gearbox_d/2; //TODO:
      if(pf_smooth) {
       pfbd = pf_d(pf)+2*pf_shell;
       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-mounthole_depth/2-(bridges?layer_height:-epsilon)])
     mirror([0,0,1])
     cylinder(d=mount_screw_d+mount_screw_d_tolerance,
              h=mount_screw_l-mounthole_depth/2+1,
              $fn=fnd*(mount_screw_d+mount_screw_d_tolerance));
     translate([0,0,mount_screw_l-mounthole_depth/2])
     cylinder(d=mount_screwhead_d,h=body_h+1,$fn=fnd*mount_screwhead_d);
    }//for
    // pushfit
    translate([0,0,filament_elevation])
-   rotate([0,0,45]) translate([pulley_d/2,0,0])
+   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,$fn=fnd*filament_guide_d);
     translate([0,-filament_guide_d/2/sqrt(2),0])
     rotate([0,0,45])
     cube(size=[filament_guide_d/2,filament_guide_d/2,gearbox_d],center=true);
    }//rotate translate rotate translate rotate translate
    // pulley
    cylinder(d=pulley_d+pulley_clearance,h=body_h+1,$fn=fnd*(pulley_d+pulley_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(
     (mount_d/sqrt(2)/2+mount_screw_d+pf_h(pf)+gearbox_d/2)
     /
     (
-     pulley_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
    
    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]);
    }
    //translate([-mount_d/2,-longwing,filament_elevation])