include <utils.scad>
// strength factor, set to 1 for real prints
-//$strf = 0.25;
+//$strf = 0.33;
$strf = 1;
brk_recess_actual = 5.20;
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;
brk_nearbolt_recess_dia = 8.86 + 1.5;
brk_nearbolt_recess_depth = 1.09 + 0.25;
+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 = 0.0;
+brk_bolt_len_slop = 0.5;
brk_bolt_nut_th = 3.89;
brk_bolt_nut_across_flats = 7.86 + 0.50;
foreaftmaint_y_slop = -0.25;
foreaftmaint_top_block_zs = [34.0, 39.0]; // rearwards from bolt hole
-main_sz_y = $strf * 18;
+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 * 18;
+main_sz_core_z = $strf * 12;
// "length" in for-aft direction of interaction with rack rail
-min_on_rail_sz_z = $strf * 25;
+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;
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;
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) =
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 ],
// 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, $fn = 6 );
}
}
ybot,
adapt_main_top_y - grasp_large_r
])
- for (dx= [-1,+1] * rack_rail_dia/2)
+ for (dx= [/*-1,*/ +1] * rack_rail_dia/2)
translate([ -$foreaftmaint_rail_z + dx, y ])
circle(r= grasp_large_r);
}
- translate([0, adapt_main_top_y])
- rectfromto([-500, 0], [500, 500]);
+ 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);
}
}
$foreaftmaint_rail_z = brk_block_z/2 + $foreaftmaint_dz - foreaftmaint_y_slop;
+ translate([0,0,brk_block_z/2])
+ mirror([0,0, $reverse_sign > 0 ? 0 : 1])
+ translate([0,0,-brk_block_z/2])
difference(){
union(){
MainExtrude(main_sz_lhs_z){
}
if ($strf<1) {
MainExtrude(max(brk_block_z, main_sz_rhs_z)){
- rectfromto([-8, 0],
+ 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]);
}
FamLinextr(){
- rectfromto([ -$foreaftmaint_rail_z, adapt_main_top_y ],
- [ 0, block_y_min]);
- rectfromto([ -foreaftmaint_top_block_zs[0] + bolt_z, 0 ],
- [ -foreaftmaint_top_block_zs[1] + bolt_z, block_y_min] );
+ if ($foreaftmaint_top_block) {
+ rectfromto([ -foreaftmaint_top_block_zs[0] + bolt_z, 0 ],
+ [ -foreaftmaint_top_block_zs[1] + bolt_z, block_y_min] );
+ }
FamGraspElevation();
}
- RackShear()
- FamLinextr()
- 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_lhs_z+main_sz_rhs_z) {
}
}
-module RackForDemo(){ ////toplevel
+module ForRackForDemo(){
elevation = elevation_of_bolt_for(rear_to_cross_rail);
rack_rail_y = rack_rail_y_of_elevation(elevation);
- rotate([-atan(rack_shear_ratio), 0,0])
- translate([0, rack_rail_y, brk_block_z/2 + rack_rail_y*rack_shear_ratio]) {
- for (m=[0]) mirror([m,0,0]) {
- linextr(-50, 50 + rear_to_cross_rail)
- translate([rack_rail_x, 0])
- circle(r= rack_rail_dia/2);
- }
- translate([0,0, rear_to_cross_rail])
- linextr_x_yz(rack_rail_x, -rack_rail_x)
+ 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=
+ 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= 0);
+ $foreaftmaint_dz= front_to_cross_rail);
}
module Rear(){ ////toplevel
- Principal($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 FrontDemo(){ ////toplevel
- SomeDemo() Front();
+ SomeDemo() rotate([180,0,0]) Front();
}
module RearDemo(){ ////toplevel
SomeDemo() Rear();
module RearRackDemo(){ ////toplevel
rotate([atan(rack_shear_ratio),0,0]) SomeDemo() {
Rear();
- %RackForDemo();
+ translate([0, 0, -rear_bolt_to_front_bolt])
+ rotate([180,0,0]) Front();
+ %RackForDemoRails();
+ color("blue") RackForDemoCrosses();
}
}
~ianmdlvl / reprap-play.git / blobdiff