include <utils.scad>
// strength factor, set to 1 for real prints
-//$strf = 0.25;
+//$strf = 0.33;
$strf = 1;
brk_recess_actual = 5.20;
-rack_rail_dia = 10.40 + 0.50;
-rack_width_inner = 115.86 + 1.0; // between insides of rails
+rack_rail_dia = 10.40 + 0.30;
+rack_width_inner = 115.86 - 1.0; // between insides of rails
rear_elevation_nominal = 10.04;
-// ^ top of rack to bottom of bracket, at rear bolt hold
-rear_to_front_distance = 230;
-rear_to_cross_rail = 19.65; // bolt centre to rail centre, rail to rear
+// ^ top of rack to bottom of bracket, at rack cross rail (fam)
+rear_to_front_distance = 230; // rack cross rail (fam) to very front end
+rear_to_cross_rail = 43.05; // bolt centre to rail centre, rail to rear
+rear_bolt_to_front_bolt = 155.4;
+front_elevation_nominal = 0; // this parameter adjusts rear too somehow?
+
+cross_rail_distance = 232.09;
general_gap_y = 1.0;
+support_bridge_gap_z = 1.0;
strap_w = 8.0 + 1.0;
strap_th = 2.5;
strap_guide_sz = 1;
brk_block_xw = 68.5;
-brk_block_z = 14.55 - 0.75;
+brk_block_z = 14.55 - 0.00;
-brk_bolt_dia = 4.0 + 0.5;
+brk_bolt_dia = 5.0 + 0.5;
brk_nearbolt_recess_dia = 8.86 + 1.5;
brk_nearbolt_recess_depth = 1.09 + 0.25;
-brk_bolt_eff_len = 11.78 - 1.0; // inside of recess, to end of bolt
-brk_bolt_len_slop = 2.0;;
+bolt_nut_around = 5;
+bolt_nut_around_y_extra = 3;
+
+brk_bolt_eff_len = 11.78; // inside of recess, to end of bolt
+brk_bolt_len_slop = 0.5;
brk_bolt_nut_th = 3.89;
brk_bolt_nut_across_flats = 7.86 + 0.50;
fit_slope_len = 5;
-foreaftmaint_r_slop = 0.75;
+// "foreaftmaint" aka "fam" is the hook-like part that stops
+// the adapter sliding forwards/backwards along the rails
+foreaftmaint_r_slop = 0.0;
+foreaftmaint_y_slop = -0.25;
+foreaftmaint_top_block_zs = [34.0, 39.0]; // rearwards from bolt hole
-main_sz_y = $strf * 20;
-grasp_sz = $strf * 12;
+main_sz_y = $strf * 12;
+grasp_sz = $strf * 6;
+grasp_thin_sz = $strf * 0.5;
beside_strap_sz = $strf * 8;
+main_sz_core_z = $strf * 12;
+
+// "length" in for-aft direction of interaction with rack rail
+min_on_rail_sz_z = $strf * 18;
+
+// when printer produces support
+support_around = 1.7; // how far does the support extend around (in XY)
+support_remnant = 0.75; // how much frass remains attached (Z height)
$fa=10;
$fs=1;
// calculated
-main_sz_z = beside_strap_sz*2 + strap_w;
+bolt_z = -brk_block_z/2;
+
+front_to_rear_elevation_change =
+ rear_elevation_nominal - front_elevation_nominal;
+
+main_sz_rhs_z = max(min_on_rail_sz_z, beside_strap_sz*2 + strap_w);
+main_sz_lhs_z = min_on_rail_sz_z;
+
main_sz_x_fam = main_sz_y;
brk_bottom_y = -brk_recess_actual;
-adapt_main_top_y = brk_bottom_y + general_gap_y;
+adapt_main_top_y = brk_bottom_y - general_gap_y;
// on LHS, so -ve
rack_rail_x = -(rack_width_inner/2 + rack_rail_dia/2);
rack_rail_outer_x = -(rack_width_inner/2 + rack_rail_dia);
grasp_large_r = (rack_rail_dia + grasp_sz)/2;
+grasp_small_r = (rack_rail_dia + grasp_thin_sz)/2;
grasp_large_x = rack_rail_outer_x + grasp_large_r;
+grasp_small_x = rack_rail_outer_x + grasp_small_r;
-block_x = grasp_large_x + grasp_large_r/2;
+block_x = grasp_large_x + grasp_large_r;
block_y_min = adapt_main_top_y - main_sz_y;
strap_barrel_x = rack_width_inner/2 + strap_barrel_dia/2;
-rack_shear_ratio = rear_elevation_nominal / rear_to_front_distance;
+rack_shear_ratio = - front_to_rear_elevation_change / rear_to_front_distance;
+
+front_to_cross_rail =
+ cross_rail_distance * sqrt(1 - rack_shear_ratio * rack_shear_ratio)
+ - rear_bolt_to_front_bolt
+ - rear_to_cross_rail
+ - sqrt( pow( cross_rail_distance * rack_shear_ratio, 2 )
+ - pow( front_to_rear_elevation_change, 2 ) )
+ ;
brk_bolt_nut_top_y = -brk_nearbolt_recess_depth
- brk_bolt_eff_len + brk_bolt_nut_th + brk_bolt_len_slop;
brk_bolt_nut_r = brk_bolt_nut_across_flats/2 / cos(360/12);
+function elevation_of_bolt_for(z) = rear_elevation_nominal
+ + front_elevation_nominal
+ + (z - brk_block_z/2) * rack_shear_ratio;
+
+function rack_rail_y_of_elevation(elevation_nominal) =
+ brk_bottom_y - elevation_nominal - general_gap_y - rack_rail_dia/2;
+
+echo(rack_shear_ratio);
+
module GraspElevation(){
hull(){
translate([ grasp_large_x, adapt_main_top_y - grasp_large_r ])
circle(grasp_large_r);
- translate([ grasp_large_x, $rack_rail_y - rack_rail_dia/2 ])
- circle(grasp_large_r);
+ translate([ grasp_small_x, $rack_rail_y - rack_rail_dia/2 ])
+ circle(grasp_small_r);
+
+ translate([ rack_rail_x + grasp_large_r/2,
+ $rack_rail_y - rack_rail_dia/2 ])
+ circle(grasp_small_r);
translate([ grasp_large_x, $rack_rail_y + rack_rail_dia/2 ])
circle(grasp_large_r);
+
+ translate([ grasp_large_x + grasp_large_r/2,
+ $rack_rail_y + rack_rail_dia/2 ])
+ circle(grasp_large_r);
}
}
rectfromto([ -grasp_large_x, adapt_main_top_y ],
[ +grasp_large_x, adapt_main_top_y - 0.1 ]);
}
+ hull(){
+ rectfromto([ +block_x, adapt_main_top_y ],
+ [ -block_x, block_y_min ]);
+ rectfromto([ grasp_large_x, block_y_min ],
+ [ 0, block_y_min + 0.1 ]);
+ }
}
-module MainExtrude(){
- linextr(0, main_sz_z)
+module MainExtrude(z){
+ linextr(0, z)
children();
}
module RackShear(){
- s = rack_shear_ratio;
+ s = rack_shear_ratio * $reverse_sign;
multmatrix([ [ 1, 0, 0, 0 ],
[ 0, 1, s , 0 ],
[ 0, 0, 1, 0 ],
module GraspFixingElevation(){
intersection(){
union(){
- mirror([1,0]) GraspElevation();
+ hull(){
+ mirror([1,0]) {
+ GraspElevation();
+ }
+ translate([ -block_x, block_y_min ] + [0,0.1]*1 )
+ circle(0.1);
+ }
translate([ strap_barrel_x, $strap_barrel_y ])
circle(strap_barrel_dia/2 + strap_guide_sz);
}
intersection(){
translate([ rack_rail_x, $rack_rail_y ])
circle(r = rack_width_inner/2 - rack_rail_x);
- polygon([ [ 0, 0 ],
+ polygon([ [ -block_x-0.1, 0 ],
[ rack_width_inner/2, 0 ],
$rail_fixing_fit_corner,
$rail_fixing_fit_corner + [-1,-1] * fit_slope_len,
- [ -block_x, block_y_min ],
- [ 0, block_y_min ]]);
+ [ -grasp_large_x - grasp_large_r*2, block_y_min ],
+ [ -block_x-0.1 -2, block_y_min +2 ]]);
}
}
}
// Bracket support block, goes up inside bracket
// Z origin is bolt hole
module BrkBlock(){
- linextr( -brk_block_z/2,
- +brk_block_z/2 ) {
- rectfromto([ -brk_block_xw/2, adapt_main_top_y - 0.1 ],
- [ +brk_block_xw/2, 0 ]);
+ difference(){
+ linextr( -brk_block_z/2,
+ +brk_block_z/2 ) {
+ rectfromto([ -brk_block_xw/2, adapt_main_top_y - 0.1 ],
+ [ +brk_block_xw/2, 0 ]);
+ }
+ linextr_y_xz( -50, 10 ) {
+ translate([ 0, brk_block_z + bolt_z ])
+ square(center=true,
+ [ main_sz_x_fam + support_around*2,
+ support_remnant *2 ]);
+ }
}
}
circle(brk_nearbolt_recess_dia/2);
linextr_y_xz( -100, brk_bolt_nut_top_y ) {
- circle( r= brk_bolt_nut_r, $fn = 6 );
- translate([ 0, brk_bolt_nut_across_flats/2 ])
- circle( r=brk_bolt_nut_r/2, $fn = 4);
+ hull()
+ for (dz = [0, support_bridge_gap_z])
+ translate([0, dz])
+ circle( r= brk_bolt_nut_r, $fn = 6 );
}
}
-module AsForeAftMaint(){
+module IfFam(){
if ($foreaftmaint_dz) {
- translate([ 0, $foreaftmaint_rail_y, $foreaftmaint_rail_z ])
- children();
+ children();
+ }
+}
+
+module FamLinextr(){
+ IfFam()
+ linextr_x_yz(-main_sz_x_fam/2, +main_sz_x_fam/2)
+ rotate(-90)
+ children();
+}
+
+module FamGraspElevation(){
+ difference(){
+ hull(){
+ ybot = $rack_rail_y - rack_rail_dia/2 + grasp_large_r
+ - fit_slope_len * 0.5;
+ for (y = [
+ ybot,
+ adapt_main_top_y - grasp_large_r
+ ])
+ for (dx= [/*-1,*/ +1] * rack_rail_dia/2)
+ translate([ -$foreaftmaint_rail_z + dx, y ])
+ circle(r= grasp_large_r);
+ }
+ if ($foreaftmaint_cutoff) {
+ translate([ -$foreaftmaint_rail_z, 0 ])
+ rectfromto([-100, -100],
+ [0, 100]);
+ }
+ }
+}
+
+module FamStemElevation(){
+ hull(){
+ rectfromto([ -$foreaftmaint_rail_z
+ , adapt_main_top_y ],
+ [ 0, block_y_min]);
+ translate([
+ -$foreaftmaint_rail_z,
+ $rack_rail_y +
+ rack_shear_ratio * $foreaftmaint_rail_z * $reverse_sign,
+ ])
+ square([0.1, rack_rail_dia * 0.5], center=true);
}
}
module Principal(){
// calculated
- $rack_rail_y = brk_bottom_y - $elevation_nominal
- - general_gap_y - rack_rail_dia/2;
+ $rack_rail_y = rack_rail_y_of_elevation($elevation_nominal);
$strap_barrel_y = $rack_rail_y + rack_rail_dia/2 + strap_barrel_dia/2;
$rack_rail_y - rack_rail_dia/2
];
- $foreaftmaint_rail_z = brk_block_z/2 + $foreaftmaint_dz;
- $foreaftmaint_rail_y = $rack_rail_y
- + $foreaftmaint_rail_z * rack_shear_ratio;
+ $foreaftmaint_rail_z = brk_block_z/2 + $foreaftmaint_dz - foreaftmaint_y_slop;
+ translate([0,0,brk_block_z/2])
+ mirror([0,0, $reverse_sign > 0 ? 0 : 1])
+ translate([0,0,-brk_block_z/2])
difference(){
union(){
- MainExtrude(){
+ MainExtrude(main_sz_lhs_z){
GraspElevation();
}
- RackShear() MainExtrude(){
+ RackShear() MainExtrude(main_sz_rhs_z){
StrapBarrelElevation();
}
translate([ 0,0, brk_block_z/2]) {
difference(){
union(){
- MainExtrude(){
+ MainExtrude(main_sz_core_z){
BlockElevation();
}
- RackShear() MainExtrude(){
+ if ($strf<1) {
+ MainExtrude(max(brk_block_z, main_sz_rhs_z)){
+ rectfromto([-8, adapt_main_top_y + 0.1],
+ [+8, block_y_min]);
+ rectfromto([-block_x -5, adapt_main_top_y],
+ [-grasp_large_x, block_y_min]);
+ }
+ }
+ RackShear() MainExtrude(main_sz_rhs_z){
GraspFixingElevation();
}
}
- translate([0,0, main_sz_z/2]) linextr(-strap_w/2, +strap_w/2) {
+ translate([0,0, main_sz_rhs_z/2]) linextr(-strap_w/2, +strap_w/2) {
translate([ rack_width_inner/2 - strap_th, 0 ])
rectfromto([ 0, -50 ], [ 50, 50 ]);
}
}
- AsForeAftMaint(){
- linextr_x_yz(-main_sz_x_fam/2,
- +main_sz_x_fam/2){
- hull(){
- for (y = [-rack_rail_dia/2 + grasp_large_r,
- (-$foreaftmaint_rail_y
- + adapt_main_top_y - grasp_large_r)
- ])
- for (dx= [-1,+1] * rack_rail_dia/2)
- translate([ y, dx ])
- circle(r= grasp_large_r);
- }
+ FamLinextr(){
+ if ($foreaftmaint_top_block) {
+ rectfromto([ -foreaftmaint_top_block_zs[0] + bolt_z, 0 ],
+ [ -foreaftmaint_top_block_zs[1] + bolt_z, block_y_min] );
+ }
+ FamGraspElevation();
+ }
+ intersection(){
+ union(){
+ RackShear()
+ FamLinextr()
+ FamGraspElevation();
+ FamLinextr()
+ FamStemElevation();
}
+ translate([ 0,
+ adapt_main_top_y - 50,
+ $foreaftmaint_rail_z ])
+ cube(center=true, 100);
+ }
+
+ linextr_y_xz( block_y_min - bolt_nut_around_y_extra , adapt_main_top_y )
+ intersection(){
+ translate([ 0, brk_block_z/2 ])
+ circle(r = bolt_nut_around + brk_bolt_nut_r );
+ rectfromto([-100, 0], [+100,+100]);
}
}
- RackShear() linextr(-10, main_sz_z+10) {
+ RackShear() linextr(-10, main_sz_lhs_z+main_sz_rhs_z) {
for (mx=[0,1]) {
mirror([mx,0]) {
translate([ rack_rail_x, $rack_rail_y ]){
}
}
- // Distance from bolt hole, in backwards direction
- AsForeAftMaint(){
- linextr_x_yz(+rack_rail_x,
- -rack_rail_x) {
+ RackShear() IfFam(){
+ // Distance from bolt hole, in backwards direction
+ cr = rack_rail_dia/2 + foreaftmaint_r_slop;
+ translate([ 0, $rack_rail_y, $foreaftmaint_rail_z ])
+ linextr_x_yz(+rack_rail_x,
+ -rack_rail_x) {
hull(){
for (dy=[0,50]) {
translate([-dy,0])
- circle(r= rack_rail_dia/2 + foreaftmaint_r_slop);
+ circle(r= cr);
+ }
+ }
+ hull(){
+ for (dd=[[0,0], [-1,-1], [-1,+1]]) {
+ translate(
+ [-1, 0] * (rack_rail_dia - fit_slope_len)
+ + 20 * dd
+ )
+ circle(r= cr);
}
}
}
}
}
+module ForRackForDemo(){
+ elevation = elevation_of_bolt_for(rear_to_cross_rail);
+ rack_rail_y = rack_rail_y_of_elevation(elevation);
+
+ rotate([atan(
+ front_to_rear_elevation_change /
+ cross_rail_distance
+ ), 0,0])
+ translate([0, rack_rail_y, brk_block_z/2 + rack_rail_y*rack_shear_ratio])
+ children();
+}
+
+module RackForDemoRails(){
+ ForRackForDemo() {
+ for (m=[0]) mirror([m,0,0]) {
+ linextr(-(50 + cross_rail_distance), 50 + rear_to_cross_rail)
+ translate([rack_rail_x, 0])
+ circle(r= rack_rail_dia/2);
+ }
+ }
+}
+
+module RackForDemoCrosses(){
+ ForRackForDemo() {
+ for (z = [
+ rear_to_cross_rail,
+ rear_to_cross_rail - cross_rail_distance,
+ ]) {
+ translate([0,0,z])
+ linextr_x_yz(rack_rail_x, -rack_rail_x)
+ circle(r= rack_rail_dia/2, $fn=8);
+ }
+ }
+}
+
module Front(){ ////toplevel
- // xxx elevation is wrong
- Principal($elevation_nominal=0, $foreaftmaint_dz=0);
+ rotate([180,0,0])
+ Principal($reverse_sign = -1,
+ $foreaftmaint_top_block = false,
+ $foreaftmaint_cutoff = true,
+ $elevation_nominal=
+ elevation_of_bolt_for(rear_to_cross_rail + rear_bolt_to_front_bolt),
+ $foreaftmaint_dz= front_to_cross_rail);
}
module Rear(){ ////toplevel
- Principal($elevation_nominal=rear_elevation_nominal,
+ Principal($reverse_sign = +1,
+ $foreaftmaint_top_block = true,
+ $foreaftmaint_cutoff = false,
+ $elevation_nominal=
+ elevation_of_bolt_for(rear_to_cross_rail),
$foreaftmaint_dz= rear_to_cross_rail);
}
-module Demo(){ ////toplevel
+module SomeDemo(){
rotate([90, 0, 0]){
-
- Rear();
+ children();
color("blue")
translate([ 0, -2, -4 ])
square(center=true, [ brk_overall_w, 1 ]);
+ color("red")
+ translate([ 0, -brk_nearbolt_recess_depth, -4 ])
+ linextr_y_xz(-brk_bolt_eff_len, 0)
+ circle(r = brk_bolt_dia/2);
+
+ }
+}
+
+module FrontDemo(){ ////toplevel
+ SomeDemo() rotate([180,0,0]) Front();
+}
+module RearDemo(){ ////toplevel
+ SomeDemo() Rear();
+}
+module RearRackDemo(){ ////toplevel
+ rotate([atan(rack_shear_ratio),0,0]) SomeDemo() {
+ Rear();
+ translate([0, 0, -rear_bolt_to_front_bolt])
+ rotate([180,0,0]) Front();
+ %RackForDemoRails();
+ color("blue") RackForDemoCrosses();
}
}
~ianmdlvl / reprap-play.git / blobdiff