x-end: refine integration with MK3 idler tensioner

[clinton/prusa3.git] / box_frame / x-end.scad

// PRUSA iteration3
// X end prototype
// GNU GPL v3
// Josef Průša <iam@josefprusa.cz> and contributors
// http://www.reprap.org/wiki/Prusa_Mendel
// http://prusamendel.org

// Also includes code from Wilson and Wilson2, (c) Marty Rice
// https://github.com/mjrice/wilson

// major issues with rev 3

// - motor side screw hole conflicts with switch / other rear mount is
//   inaccessible without removing the leadscrew from the nut

use <bushing.scad>
include <configuration.scad>

pushfit_d = bushing_xy[0] * 2 + 0.2;
thinwall = single_wall_width * 6; // 3 perimeters
vertical_bushing_base_size = bushing_z[1]*2 + 2 * thinwall;

x_box_length = 45; // TODO: auto-adjust based on bearing size?
// z position of rotor shaft
motor_shaft_z = 30.25;

// todo: add ghost bearing model to make it easier to spot check if
// everything is aligned
module vertical_bushing_base(){
     translate(v=[-2-vertical_bushing_base_size/4,0,x_box_height/2]) cube(size = [4+vertical_bushing_base_size/2,vertical_bushing_base_size,x_box_height], center = true);
     cylinder(h = x_box_height, r=vertical_bushing_base_size/2, $fn = 90);
}

module vertical_bushing_holes(){
  // FIXME: is extra cut necessary? check conf_bushing
  bushing_cut_extra = 0.2; // padding so it's not too tight
  translate(v=[0,0,-4]) cylinder(h = x_box_height + 3, r=bushing_z[1] + bushing_cut_extra, $fn = 60);
  translate(v=[0,0,x_box_height-4]) cylinder(h=x_box_height,r=bushing_z[1]-1,$fn=60);
  // TODO: is slit too wide or too low? Wilson increased width from 1
  // -> 2 mm, slit also might need to end 1-2mm before the base
  #rotate(a=[0,0,-50]) translate(v=[thinwall*2 + 1,0,x_box_height/2 - 2]) cube(size = [bushing_z[2]/2, 2 ,x_box_height], center = true);
  translate([0,0,-1]) cylinder(h=9,r1=bushing_z[1]+thinwall/2+1,r2=4,$fn=60);
}

module nut_trap_base () {
     // TODO: cube doesn't line up with edge of base, cylinder is slightly asymmetrical
     // adapt newer nut trap from prusa i3 mk3 instead of wilson2
     cube(size=[16,21,8],center=true);
     translate ([2,0,0]) cylinder(h=8,r=12.5,$fn=50,center=true);
}

module nut_trap () {
     union() {
               // center post of brass nut
                   cylinder(h=12,r=5.45,$fn=50,center=true);
                   // holes for m3 screws in brass nut
                   translate(v=[8,0,0]) cylinder(h=12,r=1.8,$fn=20,center=true);
		   #rotate([0,0,90]) translate(v=[8,0,0]) cylinder(h=12,r=1.8,$fn=20,center=true);
		   rotate([0,0,180]) translate(v=[8,0,0]) cylinder(h=12,r=1.8,$fn=20,center=true);
		   #rotate([0,0,270]) translate(v=[8,0,0]) cylinder(h=12,r=1.8,$fn=20,center=true);
     }
}

// x position of edge of main block (facing frame), for attaching objects to it
function x_base_back() = -10 - bushing_xy[0] - x_box_width/2;
// y position of edge of main block facing away from x-axis
function x_base_outside() = vertical_bushing_base_size/2;
// y position of edge of main block facing toward the x-axis
function x_base_inside() = -x_box_length/2 - vertical_bushing_base_size/2;
// z position of motor shaft (for aligning idler pulley)
function x_motor_shaft_z() = motor_shaft_z; // TODO: if it's straightforward, return vector [x,y,z]. x = x_base_inside()

module x_end_base(){
// Main block
translate(v=[-10 - bushing_xy[0], -x_box_length/2 + vertical_bushing_base_size/2,x_box_height/2]) cube(size = [x_box_width,x_box_length,x_box_height], center = true);
// Bearing holder
 vertical_bushing_base();
//Nut trap
 translate(v=[-4+zmotor_delta_x,-17-zmotor_delta_y,4]) nut_trap_base ();
}

// TODO: x translation of belt and smooth rods needs to adapt to
// x_end_width and motor/idler pulley position.

module x_end_holes(){
 vertical_bushing_holes();
 // Belt hole
 translate(v=[-1,0,0]){
 // Stress relief
 translate(v=[-5.5-10+1.5,-bushing_z[1]-4,30]) cube(size = [20,1,28], center = true);
 // Cut out for belt (this is NOT centered because the motor isn't centered)
 x_box_offset = -x_box_length/2 + vertical_bushing_base_size/2;
 difference(){
	translate(v=[-5.5-10+1.5, x_box_offset ,30]) cube(size = [10, x_box_length + 1,28], center = true);

	// Nice edges
	translate(v=[-5.5-10+1.5,x_box_offset,30+23]) rotate([0,45,0]) cube(size = [10,x_box_length + 1,28], center = true);
	translate(v=[-5.5-10+1.5,x_box_offset,30+23]) rotate([0,-45,0]) cube(size = [10,x_box_length + 1,28], center = true);
	translate(v=[-5.5-10+1.5,x_box_offset,30-23]) rotate([0,45,0]) cube(size = [10,x_box_length + 1,28], center = true);
	translate(v=[-5.5-10+1.5,x_box_offset,30-23]) rotate([0,-45,0]) cube(size = [10,x_box_length + 1,28], center = true);

 }
}


 // FIXME: confirm length of smooth rod doesn't change when x_box_length or bearing size changes
 // should also make sure this is long enough if x-ends somehow end up larger than 50mm
 // TODO: needs to shift top rod as diameter increases, wall is very
 // thing for 10mm, and fails entirely for 12mm
 translate([-10 - bushing_xy[0], 0, 0]) {
      // Top pushfit rod
      #translate([0, -41.5, 6]) rotate([-90, 0, 0]) pushfit_rod(pushfit_d, 50);
      // Bottom pushfit rod
      translate([0, -41.5, xaxis_rod_distance+6]) rotate([-90, 0, 0]) pushfit_rod(pushfit_d, 50);
 }

// Nut trap
 translate(v=[zmotor_delta_x,-17-zmotor_delta_y,3]) rotate ([0, 0, 45]) nut_trap ();
}


// Final prototype
module x_end_plain(){
 difference(){
  x_end_base();
  x_end_holes();
 }
}

x_end_plain();


module pushfit_rod(diameter,length){
 translate([0,-0.3,0])  cylinder(h = length, r=diameter/2, $fn=30);
 translate([0,0.3,0])  cylinder(h = length, r=diameter/2, $fn=30);
 // TODO: reintroduce teardrop holes?
// difference(){
// 	translate(v=[0,-diameter/2.85,length/2]) rotate([0,0,45]) cube(size = [diameter/2,diameter/2,length], center = true);
// 	translate(v=[0,-diameter/4-diameter/2-0.4,length/2]) rotate([0,0,0]) cube(size = [diameter,diameter/2,length], center = true);
// }

}