Package: openscad
Version: 2011.12-3
The attached test file has what is arguably a bug. On line 197 it
says
rotate([90 + led_angle])
where it should say
rotate([90 + led_angle, 0, 0])
However, when fed to openscad the results are unpredictable. Amongst
the outcomes I have seen:
- the hole (which is the cylinder cut out near the top of the
object) appears with various unpredictable alignments
- assertion failures from openscad
CGAL error: assertion violation!
Expression : is_finite(d)
File : /usr/include/CGAL/GMP/Gmpq_type.h
Line : 132
Explanation:
Refer to the bug-reporting instructions at
http://www.cgal.org/bug_report.html
Aborted
- the behavour I intended when I wrote the file
IMO the following would be acceptable behaviours:
- reject the input file
- treat the missing elements as 0
- if documented, interpret the input in some entirely different way
I conjecture that the part of openscad code which interprets the array
argument to the rotate() command fails to check that the array has 3
elements before reading all 3 of them - and as a result gets
unpredictable values from whatever happens to be next in memory.
Ian.
// -*- C -*-
led_dia = 5 + 0.6;
led_depth = 5;
led_tip_height_above_crossbar = 70;
led_angle = -60;
crossbar_dia = 25; // fixme
vert_space_inside = 8;
backfront_space_inside = 12;
width_space_inside = 10;
backfront_mate_size = 25;
tower_frontheight = 10;
tower_base_height = 20;
tower_slot_width = 3;
cableclamp_ctie_width = 4.0 + 1.0;
cableclamp_ctie_thick = 2.5 + 0.5;
lidclamp_ctie_width = 4.0 + 1.0;
lidclamp_ctie_thick = 2.5 + 0.5;
base_ctie_width = 4.0 + 1.0;
base_ctie_thick = 2.5 + 0.5;
tube_ctie_width = 4.0 + 1.0;
tube_ctie_thick = 2.5 + 0.5;
// tuning
tower_over_angle = 45;
tower_wall_thick = 1.6;
tower_forehead_angle = 30;
lid_wall_thick = 1.6;
lid_slop = 0.75;
//cableclamp_ctie_anchor = 5;
lidclamp_cableclamp_ctie_between = 0;
base_ctie_anchor = 5;
tube_ctie_anchor = 5;
protrusion_size = 2;
protrusion_none_frontback = 10;
protrusion_slop = 0.25;
cableclamp_ctie_z = tower_frontheight/2;
towerleg_backfront = 5;
towerleg_width = 3;
towerleg_foot_gap = 2;
towerleg_foot_backfront = 20;
towerleg_foot_width = 40;
towerleg_foot_height = 10;
towerleg_yslope = 0.7;
towerleg_xslope = 0.3;
echo(sqrt(towerleg_yslope*towerleg_yslope+towerleg_xslope*towerleg_xslope));
//--- tests ---
test_width = 24;
test_height = 24;
test_thicks = [9,14,21];
module Tests(){ ////toplevel
for (thicki=[0:len(test_thicks)-1]) {
translate([thicki*test_width-0.5, 0, 0]) {
difference(){
cube([test_width,
test_thicks[thicki] + led_depth,
test_height]);
translate([test_width/2, -1, test_height/2])
rotate([-90,0,0])
cylinder(r=led_dia/2, h=led_depth+1, $fn=30);
}
}
}
}
//Tests();
//--- real thing ---
// calculated
tower_overhang = led_dia * 2.5;
tower_width = width_space_inside + tower_wall_thick*2;
tower_over_max_y = tower_overhang * sin(tower_over_angle);
tower_over_max_z = tower_frontheight + tower_overhang * cos(tower_over_angle);
tower_total_max_z = tower_over_max_z + vert_space_inside + led_depth;
tower_rearwall_y = -(backfront_space_inside + tower_wall_thick);
led_head_y = tower_over_max_y/2;
led_head_z = tower_frontheight + tower_overhang*sin(tower_over_angle)/2;
backfront_mate_extra = (backfront_mate_size - (-tower_rearwall_y));
tower_height_contribution = led_head_z + tower_base_height;
base_ctie_anchor_eff = base_ctie_anchor+base_ctie_thick/2;
tube_ctie_anchor_eff = tube_ctie_anchor+tube_ctie_thick/2;
base_width = 0.7 * crossbar_dia;
base_backfront = backfront_mate_extra - tower_rearwall_y;
base_height = led_tip_height_above_crossbar - tower_height_contribution;
protrusion_frontback = base_backfront - protrusion_none_frontback;
echo(tower_height_contribution, base_height);
module TowerWallCrossSection(){
// generates a 2D shape - a polygon
// x is what is going to be -y
// y is what is going to be z
polygon([[0, 0],
[0, tower_frontheight],
[-tower_over_max_y, tower_over_max_z],
[-tower_over_max_y
+ tan(tower_forehead_angle) * (vert_space_inside + led_depth),
tower_total_max_z],
[-tower_rearwall_y, tower_total_max_z],
[-tower_rearwall_y, 0],
[-tower_rearwall_y, -tower_base_height],
[-backfront_mate_extra, -tower_base_height]],
convexity=5);
}
module TowerWallSomeEdge(front){
minkowski(){
difference(){
TowerWallCrossSection();
translate([front ? 0.10 : -0.10, 0])
TowerWallCrossSection();
}
circle(r=tower_wall_thick, $fn=8);
}
}
module TowerBulkCrossSection(){
intersection(){
TowerWallCrossSection();
union(){
translate([-led_head_y, led_head_z])
circle(r = led_depth);
TowerWallSomeEdge(true);
translate([-50, -50])
square([100, 50]);
}
}
}
module TowerRearWallCrossSection(){
intersection(){
TowerWallCrossSection();
union(){
intersection(){
translate([0,-10]) square([100, 10+led_head_z]);
TowerWallSomeEdge(false);
}
TowerBulkCrossSection();
}
}
}
module TowerCrossSectionDemo(){
%TowerWallCrossSection();
//TowerBulkCrossSection();
TowerRearWallCrossSection();
}
module TowerMain(){
for (mir=[0,1])
mirror([mir,0,0]) rotate([90,0,-90]) {
translate([0,0, tower_width/2-tower_wall_thick])
linear_extrude(height=tower_wall_thick) {
TowerWallCrossSection();
}
translate([0,0,-1])
linear_extrude(height=tower_width/2+0.9)
union(){
TowerBulkCrossSection();
hull(){
intersection(){
TowerWallCrossSection();
translate([-30, -30])
square([30 + 0.1, 30 + tower_frontheight]);
}
}
}
translate([0,0, tower_slot_width/2])
linear_extrude(height=(tower_width - tower_slot_width)/2 - 0.2)
TowerRearWallCrossSection();
}
}
module LedHole(){
translate([0, led_head_y, led_head_z])
rotate([90 + led_angle])
translate([0,0,-10])
cylinder(r=led_dia/2, h=led_depth+1+10, $fn=26, $fa=10);
}
module TowerProper(){
difference(){
TowerMain();
LedHole();
// passages for cable ties
translate([0,
tower_rearwall_y/2,
cableclamp_ctie_z
+ cableclamp_ctie_width/2 + lidclamp_ctie_thick/2
+ lidclamp_cableclamp_ctie_between])
cube([50, lidclamp_ctie_width, lidclamp_ctie_thick], center=true);
translate([0,
(backfront_mate_extra+tower_rearwall_y)/2,
-tower_base_height
+ max(protrusion_size + protrusion_slop + 0.1,
base_ctie_anchor_eff)])
cube([50, base_ctie_width, base_ctie_thick], center=true);
// for (extra_y=[0, -(cableclamp_ctie_thick + cableclamp_ctie_anchor)]) {
// translate([-tower_width/2,
// -cableclamp_ctie_thick/2 - tower_wall_thick + extra_y,
// cableclamp_ctie_z])
// cube([tower_wall_thick+2,
// cableclamp_ctie_thick,
// cableclamp_ctie_width], center=true);
// }
for (mir=[0,1])
mirror([mir,0,0]) {
translate([tower_width/4, 20, cableclamp_ctie_z])
cube([cableclamp_ctie_thick,
tower_wall_thick*2+1+40,
cableclamp_ctie_width],
center=true);
}
translate([0, tower_rearwall_y, -tower_base_height])
BaseRegistrationProtrusion(protrusion_slop);
}
}
module Tower(){ ////toplevel
TowerProper();
for (mir=[0,1]) {
mirror([mir,0,0]){
translate([0,
tower_rearwall_y + 0.1,
-1])
mirror([0,0,1])
multmatrix([[1,0, towerleg_xslope,0],
[0,1,-towerleg_yslope,0],
[0,0,1,0],
[0,0,0,1]])
cube([towerleg_width, towerleg_backfront, tower_base_height-2]);
}
}
translate([-towerleg_foot_width/2,
tower_rearwall_y - towerleg_foot_gap,
-tower_base_height])
mirror([0,1,0])
cube([towerleg_foot_width, towerleg_foot_backfront, towerleg_foot_height]);
}
module TowerMainHull(){
hull(){ TowerMain(); }
}
module Lid(){
intersection(){
difference(){
minkowski(){
TowerMainHull();
sphere(r=lid_wall_thick+lid_slop, $fn=8);
}
minkowski(){
TowerMainHull();
sphere(r=lid_slop, $fn=6);
}
}
translate([-50,-50,led_head_z]) cube([100,100,100]);
}
}
module LidT(){ ////toplevel
rotate([180,0,0]) Lid();
}
module BaseRegistrationProtrusion(extra){
size = protrusion_size + extra;
translate([0, base_backfront/2, 0]){
hull(){
translate([0,0, -0.5])
cube([protrusion_size*2, protrusion_frontback, 1.0], center=true);
translate([0, 0, protrusion_size-0.5])
cube([0.05, protrusion_frontback-protrusion_size*2, 1.0], center=true);
}
}
}
module Base(){
difference(){
mirror([0,0,1]){
hull(){
translate([-tower_width/2, 0, 0])
cube([tower_width, base_backfront, 0.1]);
translate([-base_width/2, 0, base_height])
cube([base_width, base_backfront, crossbar_dia/2]);
}
}
translate([0, base_backfront/2, -base_ctie_anchor_eff])
cube([100, base_ctie_width, base_ctie_thick], center=true);
translate([0, base_backfront/2, -base_height + tube_ctie_anchor_eff])
cube([100, tube_ctie_width, tube_ctie_thick], center=true);
translate([0, -1, -(base_height + crossbar_dia/2)])
rotate([-90,0,0])
cylinder(r=crossbar_dia/2, h=101);
}
BaseRegistrationProtrusion(0.0);
}
module BaseT(){ ////toplevel
rotate([90,0,0]) Base();
}
module Demo(){
Tower();
%Lid();
translate([0,0, 25]) Lid();
translate([0, tower_rearwall_y, -(tower_base_height+5)]) Base();
}
//TowerCrossSectionDemo();
//TowerWallSomeEdge(false);
//TowerWallFrontEdge();
//TowerMainHull();
//LidT();
Tower();
//Lid();
//BaseRegistrationProtrusion();
//Base();
//BaseT();
//Demo();
