box_frame/x-end-idler.scad

   1 // PRUSA iteration3
   2 // X end idler
   3 // GNU GPL v3
   4 // Josef Průša <iam@josefprusa.cz> and contributors
   5 // http://www.reprap.org/wiki/Prusa_Mendel
   6 // http://prusamendel.org
   7 // Alterations for reprap wilson by M. Rice <mrice411@gmail.com>
   8
   9 include <configuration.scad>
  10 use <x-end.scad>
  11 use <inc/bearing-guide.scad>
  12 use <y-drivetrain.scad>
  13
  14 // todo:
  15
  16 // Bearing is being moved back into mount and separate tensioner
  17 // removed, need to ensure the width of the slot is wide enough to fix
  18 // the bearing plus 1-2mm clearance. Can calculate along with
  19 // x_box_width in settings.scad. Unlikely there's any reason to
  20 // complicate x_box_width by checking if bearing exceeds the width
  21 // calculated based rod diameter.
  22
  23 // radius of screw hole for pulley (todo: ideally would adjust to
  24 // closest screw diameter to idler_bearing inner diameter)
  25 pulley_mount_radius = m4_diameter/2;
  26 // Y position of the pulley mount, adjusted to clear z bearing
  27 // fixme: not sure about z_delta/2 anymore
  28 pulley_mount_y = x_base_inside()
  29      // ensuring entire bearing fits inside idler
  30      + idler_bearing[0]
  31      // including flange (even if not using bearing guide since
  32      // bearings without will have their own flanges and the size of
  33      // those is not configurable)
  34      + (idler_assy_r_outer(idler_bearing) - idler_assy_r_inner(idler_bearing))
  35      // and recess by 2mm
  36      + 2
  37      - z_delta / 2;
  38 // Z position of pulley mount, adjusted so bottom of idler aligns with
  39 // bottom of motor pulley (note: in the x-carriage currently generated
  40 // this is backward since the belt runs above the carriage mounting
  41 // points)
  42 pulley_mount_z = x_motor_shaft_z () + (motor_pulley[0]/2 - idler_bearing[0]/2);
  43
  44 module x_end_idler_base(){
  45  x_end_base();
  46 }
  47
  48 module x_end_idler_holes(){
  49  x_end_holes();
  50
  51  // tensioner mount
  52  translate([-20, pulley_mount_y, pulley_mount_z]) {
  53       #rotate([0, 90, 0]) cylinder(r=pulley_mount_radius, h=33, center=true, $fn=small_hole_segments);
  54       translate([15 - 2 * single_wall_width, 0, 0]) rotate([90, 0, 90]) cylinder(r=m4_nut_diameter_horizontal / 2, h=3, $fn=6);
  55  }
  56 }
  57
  58 // Final part
  59 module x_end_idler(){
  60  mirror([0,1,0]) difference(){
  61   x_end_idler_base();
  62   x_end_idler_holes();
  63  }
  64
  65  %translate([-14 - xy_delta / 2, 25, pulley_mount_z - (max(idler_width, 16) / 2)]) x_tensioner();
  66 }
  67
  68 module x_tensioner(len=50, idler_height=max(idler_bearing[0], 16)) {
  69      // todo: scal narrow_width with size of belt hole, if that becomes scalable
  70      idlermount(len=len, rod=m4_diameter / 2 + 0.5, idler_height=idler_height, narrow_len=30, narrow_width=9);
  71 }
  72
  73 translate([-40, 0, 4 - bushing_xy[0]]) x_tensioner();
  74
  75 x_end_idler();
  76
  77 if (idler_bearing[3] == 1) {  // bearing guides
  78     translate([-39,  -60 - idler_bearing[0] / 2, 4 - bushing_xy[0]]) rotate([0, 0, 55]) {
  79         render() bearing_assy();
  80     }
  81 }