From c589a731b5e1e79e1e9dc9aa0141645743f187f2 Mon Sep 17 00:00:00 2001 From: Ian Jackson Date: Sat, 16 Sep 2023 12:46:57 +0100 Subject: [PATCH] Import threads.scad v2.5 from my objects repo to diziet-utils This was downloaded on 10.5.2023 from https://www.dkprojects.net/openscad-threads/ Signed-off-by: Ian Jackson --- diziet-utils/threads.scad | 407 +++++++++++++++++++++++++++++++++++++ threads.scad | 408 +------------------------------------- 2 files changed, 408 insertions(+), 407 deletions(-) create mode 100644 diziet-utils/threads.scad mode change 100644 => 120000 threads.scad diff --git a/diziet-utils/threads.scad b/diziet-utils/threads.scad new file mode 100644 index 0000000..b2eee23 --- /dev/null +++ b/diziet-utils/threads.scad @@ -0,0 +1,407 @@ +/* + * ISO-standard metric threads, following this specification: + * http://en.wikipedia.org/wiki/ISO_metric_screw_thread + * + * Copyright 2020 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 . + * + * Version 2.5. 2020-04-11 Leadin option works for internal threads. + * Version 2.4. 2019-07-14 Add test option - do not render threads. + * 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 .) + * 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, max (ceil (diameter*6), 25)); + + +// ---------------------------------------------------------------------------- +// 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 ()). Default: false. +// n_starts - Number of thread starts (e.g., DNA, a "double helix," has +// n_starts=2). See wikipedia Screw_thread. Default: 1. +// thread_size - (non-standard) axial width of a single thread "V" - independent +// of pitch. Default: same as pitch. +// groove - (non-standard) true = subtract inverted "V" from cylinder +// (rather thanadd protruding "V" to cylinder). Default: false. +// square - true = square threads (per +// https://en.wikipedia.org/wiki/Square_thread_form). Default: +// false. +// rectangle - (non-standard) "Rectangular" thread - ratio depth/(axial) width +// Default: 0 (standard "v" thread). +// 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. Default: 0 (no taper). +// 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 length (default: 1.0 = 1/2 thread). +// test - true = do not render threads (just draw "blank" cylinder). +// Default: false (draw threads). +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, test=false) +{ + // 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 = (test && ! internal) ? 0 : (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) { + if (! test) { + 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) { + if (! test) { + metric_thread_turns (diameter, pitch, length, internal, n_starts, + local_thread_size, groove, square, rectangle, + angle, taper); + } + } + } + + // Internal thread lead-in: take away from external solid. + if (internal) { + + // "Negative chamfer" z=0 end if leadin is 2 or 3. + if (leadin == 2 || leadin == 3) { + cylinder (r1=diameter/2, r2=diameter/2 - h*h_fac1*leadfac, h=h*h_fac1*leadfac, + $fn=n_segments); + } + + // "Negative 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]) { + cylinder (r1=tapered_diameter/2 - h*h_fac1*leadfac, h=h*h_fac1*leadfac, + r2=tapered_diameter/2, + $fn=n_segments); + } + } + } + } + + if (! internal) { + + // 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, test=false) +{ + // 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, test); +} + +// ---------------------------------------------------------------------------- +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 + ] + ); + } + } + } +} + + + diff --git a/threads.scad b/threads.scad deleted file mode 100644 index b2eee23..0000000 --- a/threads.scad +++ /dev/null @@ -1,407 +0,0 @@ -/* - * ISO-standard metric threads, following this specification: - * http://en.wikipedia.org/wiki/ISO_metric_screw_thread - * - * Copyright 2020 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 . - * - * Version 2.5. 2020-04-11 Leadin option works for internal threads. - * Version 2.4. 2019-07-14 Add test option - do not render threads. - * 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 .) - * 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, max (ceil (diameter*6), 25)); - - -// ---------------------------------------------------------------------------- -// 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 ()). Default: false. -// n_starts - Number of thread starts (e.g., DNA, a "double helix," has -// n_starts=2). See wikipedia Screw_thread. Default: 1. -// thread_size - (non-standard) axial width of a single thread "V" - independent -// of pitch. Default: same as pitch. -// groove - (non-standard) true = subtract inverted "V" from cylinder -// (rather thanadd protruding "V" to cylinder). Default: false. -// square - true = square threads (per -// https://en.wikipedia.org/wiki/Square_thread_form). Default: -// false. -// rectangle - (non-standard) "Rectangular" thread - ratio depth/(axial) width -// Default: 0 (standard "v" thread). -// 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. Default: 0 (no taper). -// 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 length (default: 1.0 = 1/2 thread). -// test - true = do not render threads (just draw "blank" cylinder). -// Default: false (draw threads). -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, test=false) -{ - // 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 = (test && ! internal) ? 0 : (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) { - if (! test) { - 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) { - if (! test) { - metric_thread_turns (diameter, pitch, length, internal, n_starts, - local_thread_size, groove, square, rectangle, - angle, taper); - } - } - } - - // Internal thread lead-in: take away from external solid. - if (internal) { - - // "Negative chamfer" z=0 end if leadin is 2 or 3. - if (leadin == 2 || leadin == 3) { - cylinder (r1=diameter/2, r2=diameter/2 - h*h_fac1*leadfac, h=h*h_fac1*leadfac, - $fn=n_segments); - } - - // "Negative 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]) { - cylinder (r1=tapered_diameter/2 - h*h_fac1*leadfac, h=h*h_fac1*leadfac, - r2=tapered_diameter/2, - $fn=n_segments); - } - } - } - } - - if (! internal) { - - // 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, test=false) -{ - // 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, test); -} - -// ---------------------------------------------------------------------------- -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 - ] - ); - } - } - } -} - - - diff --git a/threads.scad b/threads.scad new file mode 120000 index 0000000..de35975 --- /dev/null +++ b/threads.scad @@ -0,0 +1 @@ +diziet-utils/threads.scad \ No newline at end of file -- 2.30.2