Add initial libraries

This commit is contained in:
mmcwilliams 2022-12-05 22:09:19 -05:00
commit e7c68ba5a7
4 changed files with 779 additions and 0 deletions

181
knurledFinishLib_v2.scad Normal file
View File

@ -0,0 +1,181 @@
/*
* knurledFinishLib_v2.scad
*
* Written by aubenc @ Thingiverse
*
* This script is licensed under the Public Domain license.
*
* http://www.thingiverse.com/thing:31122
*
* Derived from knurledFinishLib.scad (also Public Domain license) available at
*
* http://www.thingiverse.com/thing:9095
*
* Usage:
*
* Drop this script somewhere where OpenSCAD can find it (your current project's
* working directory/folder or your OpenSCAD libraries directory/folder).
*
* Add the line:
*
* use <knurledFinishLib_v2.scad>
*
* in your OpenSCAD script and call either...
*
* knurled_cyl( Knurled cylinder height,
* Knurled cylinder outer diameter,
* Knurl polyhedron width,
* Knurl polyhedron height,
* Knurl polyhedron depth,
* Cylinder ends smoothed height,
* Knurled surface smoothing amount );
*
* ...or...
*
* knurl();
*
* If you use knurled_cyl() module, you need to specify the values for all and
*
* Call the module ' help(); ' for a little bit more of detail
* and/or take a look to the PDF available at http://www.thingiverse.com/thing:9095
* for a in depth descrition of the knurl properties.
*/
module knurl( k_cyl_hg = 12,
k_cyl_od = 25,
knurl_wd = 3,
knurl_hg = 4,
knurl_dp = 1.5,
e_smooth = 2,
s_smooth = 0)
{
knurled_cyl(k_cyl_hg, k_cyl_od,
knurl_wd, knurl_hg, knurl_dp,
e_smooth, s_smooth);
}
module knurled_cyl(chg, cod, cwd, csh, cdp, fsh, smt)
{
cord=(cod+cdp+cdp*smt/100)/2;
cird=cord-cdp;
cfn=round(2*cird*PI/cwd);
clf=360/cfn;
crn=ceil(chg/csh);
echo("knurled cylinder max diameter: ", 2*cord);
echo("knurled cylinder min diameter: ", 2*cird);
if( fsh < 0 )
{
union()
{
shape(fsh, cird+cdp*smt/100, cord, cfn*4, chg);
translate([0,0,-(crn*csh-chg)/2])
knurled_finish(cord, cird, clf, csh, cfn, crn);
}
}
else if ( fsh == 0 )
{
intersection()
{
cylinder(h=chg, r=cord-cdp*smt/100, $fn=2*cfn, center=false);
translate([0,0,-(crn*csh-chg)/2])
knurled_finish(cord, cird, clf, csh, cfn, crn);
}
}
else
{
intersection()
{
shape(fsh, cird, cord-cdp*smt/100, cfn*4, chg);
translate([0,0,-(crn*csh-chg)/2])
knurled_finish(cord, cird, clf, csh, cfn, crn);
}
}
}
module shape(hsh, ird, ord, fn4, hg)
{
x0= 0; x1 = hsh > 0 ? ird : ord; x2 = hsh > 0 ? ord : ird;
y0=-0.1; y1=0; y2=abs(hsh); y3=hg-abs(hsh); y4=hg; y5=hg+0.1;
if ( hsh >= 0 )
{
rotate_extrude(convexity=10, $fn=fn4)
polygon(points=[ [x0,y1],[x1,y1],[x2,y2],[x2,y3],[x1,y4],[x0,y4] ],
paths=[ [0,1,2,3,4,5] ]);
}
else
{
rotate_extrude(convexity=10, $fn=fn4)
polygon(points=[ [x0,y0],[x1,y0],[x1,y1],[x2,y2],
[x2,y3],[x1,y4],[x1,y5],[x0,y5] ],
paths=[ [0,1,2,3,4,5,6,7] ]);
}
}
module knurled_finish(ord, ird, lf, sh, fn, rn)
{
for(j=[0:rn-1])
assign(h0=sh*j, h1=sh*(j+1/2), h2=sh*(j+1))
{
for(i=[0:fn-1])
assign(lf0=lf*i, lf1=lf*(i+1/2), lf2=lf*(i+1))
{
polyhedron(
points=[
[ 0,0,h0],
[ ord*cos(lf0), ord*sin(lf0), h0],
[ ird*cos(lf1), ird*sin(lf1), h0],
[ ord*cos(lf2), ord*sin(lf2), h0],
[ ird*cos(lf0), ird*sin(lf0), h1],
[ ord*cos(lf1), ord*sin(lf1), h1],
[ ird*cos(lf2), ird*sin(lf2), h1],
[ 0,0,h2],
[ ord*cos(lf0), ord*sin(lf0), h2],
[ ird*cos(lf1), ird*sin(lf1), h2],
[ ord*cos(lf2), ord*sin(lf2), h2]
],
triangles=[
[0,1,2],[2,3,0],
[1,0,4],[4,0,7],[7,8,4],
[8,7,9],[10,9,7],
[10,7,6],[6,7,0],[3,6,0],
[2,1,4],[3,2,6],[10,6,9],[8,9,4],
[4,5,2],[2,5,6],[6,5,9],[9,5,4]
],
convexity=5);
}
}
}
module knurl_help()
{
echo();
echo(" Knurled Surface Library v2 ");
echo("");
echo(" Modules: ");
echo("");
echo(" knurled_cyl(parameters... ); - Requires a value for each an every expected parameter (see bellow) ");
echo("");
echo(" knurl(); - Call to the previous module with a set of default parameters, ");
echo(" values may be changed by adding 'parameter_name=value' i.e. knurl(s_smooth=40); ");
echo("");
echo(" Parameters, all of them in mm but the last one. ");
echo("");
echo(" k_cyl_hg - [ 12 ] ,, Height for the knurled cylinder ");
echo(" k_cyl_od - [ 25 ] ,, Cylinder's Outer Diameter before applying the knurled surfacefinishing. ");
echo(" knurl_wd - [ 3 ] ,, Knurl's Width. ");
echo(" knurl_hg - [ 4 ] ,, Knurl's Height. ");
echo(" knurl_dp - [ 1.5 ] ,, Knurl's Depth. ");
echo(" e_smooth - [ 2 ] ,, Bevel's Height at the bottom and the top of the cylinder ");
echo(" s_smooth - [ 0 ] ,, Knurl's Surface Smoothing : File donwn the top of the knurl this value, i.e. 40 will snooth it a 40%. ");
echo("");
}

195
path_extrude.scad Normal file
View File

@ -0,0 +1,195 @@
// path_extrude.scad -- Extrude a path in 3D space
// usage: add "use <path_extrude.scad>;" to the top of your OpenSCAD source code
// Copyright (C) 2014-2019 David Eccles (gringer) <bioinformatics@gringene.org>
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
// Determine the projection of a point on a plane centered at c1 with normal n1
function project(p, c, n) =
p - (n * (p - c)) * n / (n * n);
// determine angle between two points with a given normal orientation
// see https://stackoverflow.com/questions/14066933/
// direct-way-of-computing-clockwise-angle-between-2-vectors
// dot = p1 * p2;
// det = (p1[0]*p2[1]*n1[2] + p2[0]*n1[1]*p1[2] + n1[0]*p1[1]*p2[2]) -
// (n1[0]*p2[1]*p1[2] + p1[0]*n1[1]*p2[2] + p2[0]*p1[1]*n1[2]);
// atan2(det, dot);
// determine angle between two planar points and a centre
// with a given normal orientation
function getPlanarAngle(p1, p2, c1, n1) =
let(p1 = p1-c1, n1=n1 / norm(n1), p2=p2-c1)
atan2((p1[0]*p2[1]*n1[2] + p2[0]*n1[1]*p1[2] + n1[0]*p1[1]*p2[2]) -
(n1[0]*p2[1]*p1[2] + p1[0]*n1[1]*p2[2] + p2[0]*p1[1]*n1[2]), p1 * p2);
function c3D(tPoints) =
(len(tPoints[0]) == undef) ? // single point
c3D([tPoints])[0] :
(len(tPoints[0]) < 3) ? // collection of 2D points
tPoints * [[1,0,0],[0,1,0]] :
tPoints; // 3D points
// translate a point (or points)
function myTranslate(ofs, points, acc = []) =
(len(points[0]) == undef) ?
myTranslate(ofs, [points])[0] :
[ for(i = [0:(len(points) - 1)])
[ for(d = [0:(len(points[0])-1)]) (ofs[d] + points[i][d])]];
// rotate a point (or points)
function myRotate(rotVec, points) =
let(rotX = [[1, 0, 0],
[0, cos(rotVec[0]), -sin(rotVec[0])],
[0, sin(rotVec[0]), cos(rotVec[0])]],
rotY = [[ cos(rotVec[1]), 0,-sin(rotVec[1])],
[ 0, 1, 0],
[ sin(rotVec[1]), 0, cos(rotVec[1])]],
rotZ = [[ cos(rotVec[2]), sin(rotVec[2]), 0],
[ sin(rotVec[2]), -cos(rotVec[2]), 0],
[0, 0, 1]])
(len(points[0]) == undef) ?
myRotate(rotVec, [points])[0] :
c3D(points) * rotX * rotY * rotZ;
// Determine spherical rotation for cartesian coordinates
function rToS(pt) =
[-acos((pt[2]) / norm(pt)),
0,
-atan2(pt[0],pt[1])];
function calcPreRot(p1, p2, p3) =
let(n1=p2-p1, // normal between the two points (i.e. the plane that the polygon sits on)
n2=p3-p2,
rt1=rToS(n1),
rt2=rToS(n2),
pj1=(p2 + myRotate(rt2, [[1e42,0,0]])[0]),
pj2=project(p=(p1 + myRotate(rt1, [[1e42,0,0]])[0]), c=p2, n=n2))
getPlanarAngle(p1=pj1, p2=pj2, c1=p2, n1=n2);
function cumSum(x, res=[]) =
(len(x) == len(res)) ? concat([0], res) :
(len(res) == 0) ? cumSum(x=x, res=[x[0]]) :
cumSum(x=x, res=concat(res, [x[len(res)] + res[len(res)-1]]));
// Create extrusion side panels for one polygon segment as triangles.
// Note: panels are not necessarily be planar due to path twists
function makeSides(shs, pts, ofs=0) =
concat(
[for(i=[0:(shs-1)]) [i+ofs, ((i+1) % shs + ofs + shs) % (shs * pts),
(i+1) % shs + ofs]],
[for(i=[0:(shs-1)]) [((i+1) % shs + ofs + shs) % (shs * pts),
i+ofs, (i + ofs + shs) % (shs * pts)]]);
// Concatenate the contents of the outermost list
function flatten(A, acc = [], aDone = 0) =
(aDone >= len(A)) ? acc :
flatten(A, acc=concat(acc, A[aDone]), aDone = aDone + 1);
// Linearly interpolate between two shapes
function makeTween(shape1, shape2, t) =
(t == 0) ? shape1 :
(t == 1) ? shape2 :
[for (i=[0:(len(shape1)-1)])
(shape1[i]*(1-t) + shape2[i % len(shape2)]*(t))];
// Extrude a 2D shape through a 3D path
// Note: merge has two effects:
// 1) Removes end caps
// 2) Adjusts the rotation of each path point
// so that the end and start match up
module path_extrude(exPath, exShape, exShape2=[],
exRots = [0], exScale = [1], merge=false, preRotate=true){
exShapeTween = (len(exShape2) == 0) ?
exShape : exShape2;
shs = len(exShape); // shs: shape size
pts = len(exPath); // pts: path size
exPathX = (merge) ? concat(exPath, [exPath[0], exPath[1]]) :
concat(exPath,
[exPath[pts-1] + (exPath[pts-1] - exPath[pts-2]),
exPath[pts-1] + 2*(exPath[pts-1] - exPath[pts-2])]);
exScaleX = (len(exScale) == len(exPath)) ? exScale :
[for (i = [0:(pts-1)]) exScale[i % len(exScale)]];
preRots = [for(i = [0:(pts-1)])
preRotate ?
calcPreRot(p1=exPathX[i], // "current" point on the path
p2=exPathX[(i+1)], // "next" point on the path
p3=exPathX[(i+2)]) :
0 ];
cumPreRots = cumSum(preRots);
seDiff = cumPreRots[len(cumPreRots)-1]; // rotation difference (start - end)
// rotation adjustment to get start to look like end
seAdj = -seDiff / (len(cumPreRots));
adjPreRots = (!merge) ? cumPreRots :
[for(i = [0:(pts-1)]) (cumPreRots[i] + seAdj * i)];
adjExRots = (len(exRots) == 1) ?
[for(i = [0:(len(adjPreRots)-1)]) (adjPreRots[i] + exRots[0])] :
[for(i = [0:(len(adjPreRots)-1)]) (adjPreRots[i] + exRots[i % len(exRots)])];
phPoints = flatten([
for(i = [0:(pts-1)])
let(p1=exPathX[i],
p2=exPathX[(i+1)],
n1=p2-p1, // normal between the two points
rt1=rToS(n1))
myTranslate(p1, myRotate(rt1, myRotate([0,0,-adjExRots[i]],
c3D(makeTween(exShape, exShapeTween, i / (pts-1)) *
exScaleX[i]))))
]);
if(merge){ // just the surface, no end caps
polyhedron(points=phPoints,
faces=flatten([
for(i = [0:(pts-1)])
makeSides(shs, pts, ofs=shs*i)
])
);
} else {
polyhedron(points=phPoints,
faces=concat(
flatten([
for(i = [0:(pts-2)])
makeSides(shs, pts, ofs=shs*i)
]),
concat( // add in start / end covers
[[for(i= [0:(shs-1)]) i]],
[[for(i= [(len(phPoints)-1):-1:(len(phPoints)-shs)]) i]]
)
));
}
}
myPathTrefoil = [ for(t = [0:(360 / 101):359]) [ // trefoil knot
5*(.41*cos(t) - .18*sin(t) - .83*cos(2*t) - .83*sin(2*t) -
.11*cos(3*t) + .27*sin(3*t)),
5*(.36*cos(t) + .27*sin(t) - 1.13*cos(2*t) + .30*sin(2*t) +
.11*cos(3*t) - .27*sin(3*t)),
5*(.45*sin(t) - .30*cos(2*t) +1.13*sin(2*t) -
.11*cos(3*t) + .27*sin(3*t))] ];
myPointsOctagon =
let(ofs1=15)
[ for(t = [0:(360/8):359])
((t==90)?1:2) * [cos(t+ofs1),sin(t+ofs1)]];
myPointsChunkOctagon =
let(ofs1=15)
[ for(t = [0:(360/8):359])
((t==90)?0.4:1.9) *
[cos((t * 135/360 + 45)+ofs1+45)+0.5,sin((t * 135/360 + 45)+ofs1+45)]];
//myPoints = [ for(t = [0:(360/8):359]) 2 * [cos(t+45),sin(t+45)]];
pts=[2,0,0.5];
/*translate([0,0,0]) {
path_extrude(exRots = [$t*360], exShape=myPointsOctagon,
exPath=myPathTrefoil, merge=true);
}*/

372
threads.scad Normal file
View File

@ -0,0 +1,372 @@
/*
* ISO-standard metric threads, following this specification:
* http://en.wikipedia.org/wiki/ISO_metric_screw_thread
*
* Copyright 2017 Dan Kirshner - dan_kirshner@yahoo.com
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* See <http://www.gnu.org/licenses/>.
*
* Version 2.3. 2017-08-31 Default for leadin: 0 (best for internal threads).
* Version 2.2. 2017-01-01 Correction for angle; leadfac option. (Thanks to
* Andrew Allen <a2intl@gmail.com>.)
* Version 2.1. 2016-12-04 Chamfer bottom end (low-z); leadin option.
* Version 2.0. 2016-11-05 Backwards compatibility (earlier OpenSCAD) fixes.
* Version 1.9. 2016-07-03 Option: tapered.
* Version 1.8. 2016-01-08 Option: (non-standard) angle.
* Version 1.7. 2015-11-28 Larger x-increment - for small-diameters.
* Version 1.6. 2015-09-01 Options: square threads, rectangular threads.
* Version 1.5. 2015-06-12 Options: thread_size, groove.
* Version 1.4. 2014-10-17 Use "faces" instead of "triangles" for polyhedron
* Version 1.3. 2013-12-01 Correct loop over turns -- don't have early cut-off
* Version 1.2. 2012-09-09 Use discrete polyhedra rather than linear_extrude ()
* Version 1.1. 2012-09-07 Corrected to right-hand threads!
*/
// Examples.
//
// Standard M8 x 1.
// metric_thread (diameter=8, pitch=1, length=4);
// Square thread.
// metric_thread (diameter=8, pitch=1, length=4, square=true);
// Non-standard: long pitch, same thread size.
//metric_thread (diameter=8, pitch=4, length=4, thread_size=1, groove=true);
// Non-standard: 20 mm diameter, long pitch, square "trough" width 3 mm,
// depth 1 mm.
//metric_thread (diameter=20, pitch=8, length=16, square=true, thread_size=6,
// groove=true, rectangle=0.333);
// English: 1/4 x 20.
//english_thread (diameter=1/4, threads_per_inch=20, length=1);
// Tapered. Example -- pipe size 3/4" -- per:
// http://www.engineeringtoolbox.com/npt-national-pipe-taper-threads-d_750.html
// english_thread (diameter=1.05, threads_per_inch=14, length=3/4, taper=1/16);
// Thread for mounting on Rohloff hub.
//difference () {
// cylinder (r=20, h=10, $fn=100);
//
// metric_thread (diameter=34, pitch=1, length=10, internal=true, n_starts=6);
//}
// ----------------------------------------------------------------------------
function segments (diameter) = min (50, ceil (diameter*6));
// ----------------------------------------------------------------------------
// diameter - outside diameter of threads in mm. Default: 8.
// pitch - thread axial "travel" per turn in mm. Default: 1.
// length - overall axial length of thread in mm. Default: 1.
// internal - true = clearances for internal thread (e.g., a nut).
// false = clearances for external thread (e.g., a bolt).
// (Internal threads should be "cut out" from a solid using
// difference ()).
// n_starts - Number of thread starts (e.g., DNA, a "double helix," has
// n_starts=2). See wikipedia Screw_thread.
// thread_size - (non-standard) axial width of a single thread "V" - independent
// of pitch. Default: same as pitch.
// groove - (non-standard) subtract inverted "V" from cylinder (rather than
// add protruding "V" to cylinder).
// square - Square threads (per
// https://en.wikipedia.org/wiki/Square_thread_form).
// rectangle - (non-standard) "Rectangular" thread - ratio depth/(axial) width
// Default: 1 (square).
// angle - (non-standard) angle (deg) of thread side from perpendicular to
// axis (default = standard = 30 degrees).
// taper - diameter change per length (National Pipe Thread/ANSI B1.20.1
// is 1" diameter per 16" length). Taper decreases from 'diameter'
// as z increases.
// leadin - 0 (default): no chamfer; 1: chamfer (45 degree) at max-z end;
// 2: chamfer at both ends, 3: chamfer at z=0 end.
// leadfac - scale of leadin chamfer (default: 1.0 = 1/2 thread).
module metric_thread (diameter=8, pitch=1, length=1, internal=false, n_starts=1,
thread_size=-1, groove=false, square=false, rectangle=0,
angle=30, taper=0, leadin=0, leadfac=1.0)
{
// thread_size: size of thread "V" different than travel per turn (pitch).
// Default: same as pitch.
local_thread_size = thread_size == -1 ? pitch : thread_size;
local_rectangle = rectangle ? rectangle : 1;
n_segments = segments (diameter);
h = (square || rectangle) ? local_thread_size*local_rectangle/2 : local_thread_size / (2 * tan(angle));
h_fac1 = (square || rectangle) ? 0.90 : 0.625;
// External thread includes additional relief.
h_fac2 = (square || rectangle) ? 0.95 : 5.3/8;
tapered_diameter = diameter - length*taper;
difference () {
union () {
if (! groove) {
metric_thread_turns (diameter, pitch, length, internal, n_starts,
local_thread_size, groove, square, rectangle, angle,
taper);
}
difference () {
// Solid center, including Dmin truncation.
if (groove) {
cylinder (r1=diameter/2, r2=tapered_diameter/2,
h=length, $fn=n_segments);
} else if (internal) {
cylinder (r1=diameter/2 - h*h_fac1, r2=tapered_diameter/2 - h*h_fac1,
h=length, $fn=n_segments);
} else {
// External thread.
cylinder (r1=diameter/2 - h*h_fac2, r2=tapered_diameter/2 - h*h_fac2,
h=length, $fn=n_segments);
}
if (groove) {
metric_thread_turns (diameter, pitch, length, internal, n_starts,
local_thread_size, groove, square, rectangle,
angle, taper);
}
}
}
// chamfer z=0 end if leadin is 2 or 3
if (leadin == 2 || leadin == 3) {
difference () {
cylinder (r=diameter/2 + 1, h=h*h_fac1*leadfac, $fn=n_segments);
cylinder (r2=diameter/2, r1=diameter/2 - h*h_fac1*leadfac, h=h*h_fac1*leadfac,
$fn=n_segments);
}
}
// chamfer z-max end if leadin is 1 or 2.
if (leadin == 1 || leadin == 2) {
translate ([0, 0, length + 0.05 - h*h_fac1*leadfac]) {
difference () {
cylinder (r=diameter/2 + 1, h=h*h_fac1*leadfac, $fn=n_segments);
cylinder (r1=tapered_diameter/2, r2=tapered_diameter/2 - h*h_fac1*leadfac, h=h*h_fac1*leadfac,
$fn=n_segments);
}
}
}
}
}
// ----------------------------------------------------------------------------
// Input units in inches.
// Note: units of measure in drawing are mm!
module english_thread (diameter=0.25, threads_per_inch=20, length=1,
internal=false, n_starts=1, thread_size=-1, groove=false,
square=false, rectangle=0, angle=30, taper=0, leadin=0,
leadfac=1.0)
{
// Convert to mm.
mm_diameter = diameter*25.4;
mm_pitch = (1.0/threads_per_inch)*25.4;
mm_length = length*25.4;
echo (str ("mm_diameter: ", mm_diameter));
echo (str ("mm_pitch: ", mm_pitch));
echo (str ("mm_length: ", mm_length));
metric_thread (mm_diameter, mm_pitch, mm_length, internal, n_starts,
thread_size, groove, square, rectangle, angle, taper, leadin,
leadfac);
}
// ----------------------------------------------------------------------------
module metric_thread_turns (diameter, pitch, length, internal, n_starts,
thread_size, groove, square, rectangle, angle,
taper)
{
// Number of turns needed.
n_turns = floor (length/pitch);
intersection () {
// Start one below z = 0. Gives an extra turn at each end.
for (i=[-1*n_starts : n_turns+1]) {
translate ([0, 0, i*pitch]) {
metric_thread_turn (diameter, pitch, internal, n_starts,
thread_size, groove, square, rectangle, angle,
taper, i*pitch);
}
}
// Cut to length.
translate ([0, 0, length/2]) {
cube ([diameter*3, diameter*3, length], center=true);
}
}
}
// ----------------------------------------------------------------------------
module metric_thread_turn (diameter, pitch, internal, n_starts, thread_size,
groove, square, rectangle, angle, taper, z)
{
n_segments = segments (diameter);
fraction_circle = 1.0/n_segments;
for (i=[0 : n_segments-1]) {
rotate ([0, 0, i*360*fraction_circle]) {
translate ([0, 0, i*n_starts*pitch*fraction_circle]) {
//current_diameter = diameter - taper*(z + i*n_starts*pitch*fraction_circle);
thread_polyhedron ((diameter - taper*(z + i*n_starts*pitch*fraction_circle))/2,
pitch, internal, n_starts, thread_size, groove,
square, rectangle, angle);
}
}
}
}
// ----------------------------------------------------------------------------
module thread_polyhedron (radius, pitch, internal, n_starts, thread_size,
groove, square, rectangle, angle)
{
n_segments = segments (radius*2);
fraction_circle = 1.0/n_segments;
local_rectangle = rectangle ? rectangle : 1;
h = (square || rectangle) ? thread_size*local_rectangle/2 : thread_size / (2 * tan(angle));
outer_r = radius + (internal ? h/20 : 0); // Adds internal relief.
//echo (str ("outer_r: ", outer_r));
// A little extra on square thread -- make sure overlaps cylinder.
h_fac1 = (square || rectangle) ? 1.1 : 0.875;
inner_r = radius - h*h_fac1; // Does NOT do Dmin_truncation - do later with
// cylinder.
translate_y = groove ? outer_r + inner_r : 0;
reflect_x = groove ? 1 : 0;
// Make these just slightly bigger (keep in proportion) so polyhedra will
// overlap.
x_incr_outer = (! groove ? outer_r : inner_r) * fraction_circle * 2 * PI * 1.02;
x_incr_inner = (! groove ? inner_r : outer_r) * fraction_circle * 2 * PI * 1.02;
z_incr = n_starts * pitch * fraction_circle * 1.005;
/*
(angles x0 and x3 inner are actually 60 deg)
/\ (x2_inner, z2_inner) [2]
/ \
(x3_inner, z3_inner) / \
[3] \ \
|\ \ (x2_outer, z2_outer) [6]
| \ /
| \ /|
z |[7]\/ / (x1_outer, z1_outer) [5]
| | | /
| x | |/
| / | / (x0_outer, z0_outer) [4]
| / | / (behind: (x1_inner, z1_inner) [1]
|/ | /
y________| |/
(r) / (x0_inner, z0_inner) [0]
*/
x1_outer = outer_r * fraction_circle * 2 * PI;
z0_outer = (outer_r - inner_r) * tan(angle);
//echo (str ("z0_outer: ", z0_outer));
//polygon ([[inner_r, 0], [outer_r, z0_outer],
// [outer_r, 0.5*pitch], [inner_r, 0.5*pitch]]);
z1_outer = z0_outer + z_incr;
// Give internal square threads some clearance in the z direction, too.
bottom = internal ? 0.235 : 0.25;
top = internal ? 0.765 : 0.75;
translate ([0, translate_y, 0]) {
mirror ([reflect_x, 0, 0]) {
if (square || rectangle) {
// Rule for face ordering: look at polyhedron from outside: points must
// be in clockwise order.
polyhedron (
points = [
[-x_incr_inner/2, -inner_r, bottom*thread_size], // [0]
[x_incr_inner/2, -inner_r, bottom*thread_size + z_incr], // [1]
[x_incr_inner/2, -inner_r, top*thread_size + z_incr], // [2]
[-x_incr_inner/2, -inner_r, top*thread_size], // [3]
[-x_incr_outer/2, -outer_r, bottom*thread_size], // [4]
[x_incr_outer/2, -outer_r, bottom*thread_size + z_incr], // [5]
[x_incr_outer/2, -outer_r, top*thread_size + z_incr], // [6]
[-x_incr_outer/2, -outer_r, top*thread_size] // [7]
],
faces = [
[0, 3, 7, 4], // This-side trapezoid
[1, 5, 6, 2], // Back-side trapezoid
[0, 1, 2, 3], // Inner rectangle
[4, 7, 6, 5], // Outer rectangle
// These are not planar, so do with separate triangles.
[7, 2, 6], // Upper rectangle, bottom
[7, 3, 2], // Upper rectangle, top
[0, 5, 1], // Lower rectangle, bottom
[0, 4, 5] // Lower rectangle, top
]
);
} else {
// Rule for face ordering: look at polyhedron from outside: points must
// be in clockwise order.
polyhedron (
points = [
[-x_incr_inner/2, -inner_r, 0], // [0]
[x_incr_inner/2, -inner_r, z_incr], // [1]
[x_incr_inner/2, -inner_r, thread_size + z_incr], // [2]
[-x_incr_inner/2, -inner_r, thread_size], // [3]
[-x_incr_outer/2, -outer_r, z0_outer], // [4]
[x_incr_outer/2, -outer_r, z0_outer + z_incr], // [5]
[x_incr_outer/2, -outer_r, thread_size - z0_outer + z_incr], // [6]
[-x_incr_outer/2, -outer_r, thread_size - z0_outer] // [7]
],
faces = [
[0, 3, 7, 4], // This-side trapezoid
[1, 5, 6, 2], // Back-side trapezoid
[0, 1, 2, 3], // Inner rectangle
[4, 7, 6, 5], // Outer rectangle
// These are not planar, so do with separate triangles.
[7, 2, 6], // Upper rectangle, bottom
[7, 3, 2], // Upper rectangle, top
[0, 5, 1], // Lower rectangle, bottom
[0, 4, 5] // Lower rectangle, top
]
);
}
}
}
}

31
trap_cube.scad Normal file
View File

@ -0,0 +1,31 @@
/*
// Height of trapazoid
height = 19;
// Width of top cube
top_x = 30;
// Length of top cube
top_y = 34;
// Width of bottom cube
bottom_x = 45;
// Length of bottom cube
bottom_y = 65;
wall_thickness = 2;
*/
module trap_cube(height = 19, top_x = 30, top_y = 34, bottom_x = 45, bottom_y = 65, wall_thickness = 2) {
difference(){
hull(){
translate([0,0,height])
cube([top_x, top_y, 0.1], center=true);
cube([bottom_x, bottom_y, 0.1], center=true);
}
hull(){
translate([0,0,height])
cube([top_x - wall_thickness, top_y - wall_thickness, 0.1], center=true);
cube([bottom_x - wall_thickness, bottom_y - wall_thickness, 0.1], center=true);
}
}
}