// // Spherical Harmonics Ear Project (*SpHEAR) // // Octathingy, Second Order Ambisonics Microphone // // based on: // "A second-order soundfield microphone with improved polar pattern shape" // by Eric Benjamin, Audio Engineering Society Convention Paper 8728, // October 2012, San Francisco // // Copyright 2015-2016, Fernando Lopez-Lezcano, All Rights Reserved // nando@ccrma.stanford.edu // // 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 . // // 3d Models released under the Creative Commons license as follows: // Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) // http://creativecommons.org/licenses/by-nc-sa/4.0/ include ; include ; //// //// overrides // inner radius of mount stalk mount_radius = 4.0; //// //// default model parameters //// // size of Zapnspark printed circuit board // kicad length = 79.375 // measured length = 79.20 (2016.08.25) pcb_length = 79.20; // kicad width = 19.050 // measured width = 18.82 (2016.08.25) pcb_width = 18.85; // ultimaker spec thickness = 1.61 // measured thickness = 1.56 (w/ copper) pcb_thickness = 1.58; // tolerance to add to length and width of pcb // // measured 3d print width = 18.70 (with pcb_fit = 0.3) // actual printed = 18.70 - 0.3 = 16.97 // total correction = 18.85 - 16.97 = 1.88 // pcb_fit = 0.4; // tolerance add to thickness of pcb // // printed with pcb_tfit = 0.15 -> 1.58 + 0.15 = 1.73 (ideal printed) // measured print channel = 1.63 : 0.1 thinner (ultimaker 2 plus, 2016.08.24) // measured pcb thickness = 1.58 (othermill) // pcb_tfit = 0.15; // we leave part of the pcb exposed on the bottom of the body so that we // can solder the wires that connect the microphone with the // preamplifier, same at the top of the pcb to solder the wires // to the capsules pcb_low_exp = 12.0; pcb_hi_exp = 8.0; // lip fit for flares lip_fit = 0.15; // clearance from the bottom and top of pcb's to the start of the flare, // this adds space for the protuding molex pins on which we solder pcb_low_clear = 15.0; pcb_hi_clear = 15.0; // depth of slot into which the printed circuit board fits pcb_slot_depth = 1.0; // diameter of four conductor cable cable_diam = 9.5; // lip that mounts flares into main body box mount_lip = 10.0; // capsule array mount, height of flare and stalk flare_height = 50; stalk_height = 60; // wall thickness wall = 1.0; // back and front clearance of pcb (components and leads) pcb_front = 3.00; pcb_back = 1.80; // calculated minimum "radius" of microphone box box_radius = pcb_front + (pcb_thickness + pcb_tfit) + pcb_back + 2 * wall; // calculated main body corner radius mount_corner = box_radius - pcb_width / 2 + pcb_slot_depth + 4.0; // body to flares snap joint arm slot width snap_joint_slot_w = 0.75; // width and radius of snap joint hook that locks upper and lower flanges to body snap_joint_hook_w = 5.0; snap_joint_hook_r = 1.4; // dimensions of 12 pin male bottom connector // // Amphenol T 3635 002 // 12 pin DIN male to cable, gold plated contacts // // inner diameter of connector core conn_core_diam = 13.00 + 0.2; // outer diameter of connector core sleeve conn_core_o_diam = 17.00; // inner diameter of connector core sleeve conn_core_s_diam = 15.00; // from top of connector to sleeve conn_core_sleeve = 13.00; // from top of connector to holes conn_core_holes_h = 6.00; // between holes conn_core_holes_w = 9.20; // hole diameter conn_core_holes_d = 1.95 + 0.2; // screw head diameter conn_core_screw_d = 2.75 + 0.5; // sleeve overlap conn_core_overlap = 3.00; // shock mount parameters // ring_sep = 30.0; ring_height = 10.0; rubber_band_angle = 40; main_radius_inc = (ring_sep / 2) / tan(rubber_band_angle); // gap between internal ring and microphone body internal_ring_gap = 1.0; // connector that joins the two internal rings connector_w = 10.0; connector_d = 2.0; // wall thickness and height of shock mount rings ring_wall = 4 * wall; ring_ext_height = 6; // gap between external ring and support arm ring_arm_gap = 20; // the main body that holds the phantom power interfaces module one_pcb_slot (pcb_w, pcb_l, pcb_t, slot_d, front, back, test = false) { d = pcb_t + front + back; render() translate([-(pcb_w/2 + wall/2), -back, 0]) { // make cage with slots for pcb difference() { translate([-2 * wall, 0, 0]) { cube([pcb_w + 4 * wall, d, pcb_l]); } translate([slot_d, 0, 0]) { cube([pcb_w - 2 * slot_d, pcb_t + front + back, pcb_l]); } translate([0, back, 0]) { cube([pcb_w, pcb_t, pcb_l]); } // make top and bottom entry channels translate([slot_d, back + pcb_t/2, 0]) { rotate([0, 0, 45]) cylinder(r1 = pcb_t * 1.1, r2 = 0, h = 8.0, $fn = 4); } translate([pcb_w - slot_d, back + pcb_t/2, 0]) { rotate([0, 0, 45]) cylinder(r1 = pcb_t * 1.1, r2 = 0, h = 8.0, $fn = 4); } translate([slot_d, back + pcb_t/2, pcb_l - 8.0]) { rotate([0, 0, 45]) cylinder(r2 = pcb_t * 1.1, r1 = 0, h = 8.0, $fn = 4); } translate([pcb_w - slot_d, back + pcb_t/2, pcb_l - 8.0]) { rotate([0, 0, 45]) cylinder(r2 = pcb_t * 1.1, r1 = 0, h = 8.0, $fn = 4); } } // add spar in the back translate([-2 * wall, -back + wall, 0]) { cube([pcb_w + 4 * wall, wall, pcb_l]); } } // add capacitor if in test mode if (test) { cap_diam = 10.2; translate([0, cap_diam/2 + pcb_t, 0]) { cylinder(r = cap_diam/2, h = 20, $fn = facets); } } } module rounded_octagon(height, radius) { intersection() { cylinder(r = radius, h = height, $fn = 8); cylinder(r = radius - wall, h = height, $fn = facets); } } module rounded_octagon_wall(height, radius, wall) { difference() { rounded_octagon(height, radius); rounded_octagon(height, radius - wall); } } render_screw_holes = true; radial_pcb_offset = 17.0; module octa_mount_body(height, radius, lower_lip, upper_lip, clear) { // rotate pcb assembly so it does not interfere with the screws offset_angle = -16; // rotate individual pcb's to better use the internal space of the body twist_angle = 16; difference() { union() { difference() { union() { // main body rounded_octagon_wall(height, radius, 2 * wall); // slots for printed circuit boards intersection() { for (r = [0:360/8:360]) rotate([0, 0, r + offset_angle]) { translate([radial_pcb_offset, 0, 0]) { rotate([0, 0, 180 + twist_angle]) { one_pcb_slot(pcb_width + pcb_fit, height * 2/3, pcb_thickness + pcb_tfit, pcb_slot_depth, pcb_front, pcb_back, false); } } } // clip outside rounded_octagon(height, radius); } } // upper lip for flare to microphone translate([0, 0, height - upper_lip]) { rounded_octagon_wall(upper_lip, radius, wall + lip_fit); } // lower lip for flare to cable or connector translate([0, 0, 0]) { rounded_octagon_wall(upper_lip, radius, wall + lip_fit); } } if (render_screw_holes) { // add backplates for upper lip screws for (r = [45, 135, 225, 315]) { rotate([0, 0, r]) translate([-(radius - 3 * wall), -2.5, 0]) { cube([2, 5, height]); } } } } if (render_screw_holes) { // make eight holes in the the body for screws that hold both flares // (number 0 size, 1/4" long = thread diameter: 1.6mm, head diameter: 2.75) difference() { for (z = [lower_lip/2, height - upper_lip/2]) { for (r = [45, 135, 225, 315]) { rotate([0, 0, r]) translate([-(radius + 2 * wall), 0, z]) { rotate([0, 90, 0]) { cylinder(r = 0.7, h = radius + wall, $fn = facets); } } } } cylinder(r = radius/2, h = height); } } } } // flare from the body to the microphone stalk module octa_mount_flare(height, lip, transition, radius, top_radius, stalk_height, dot) { // bottom box difference() { union() { rounded_octagon_wall(height, radius, 2 * wall); if (render_screw_holes) { // small pedestals for the screws that attach the flare to the body // (number 0 size, 1/4" long = thread diameter: 1.6mm, head diameter: 2.75) for (r = [45, 135, 225, 315]) rotate([0, 0, r]) { translate([radius - wall - 1.75, 0, lip/2]) { rotate([0, 90, 0]) { cylinder(r = 1.5, h = 2 * wall, $fn = facets); } } } } } // flange to mount on body rounded_octagon_wall(lip + 1.00, radius - wall, wall); // and make a smooth transition to avoid overhangs translate([0, 0, lip + 1.00]) { hull() { rounded_octagon_wall(thin_mint, radius - wall, wall); translate([0, 0, 1.0]) { rounded_octagon_wall(thin_mint, radius - 2 * wall, wall); } } } if (render_screw_holes) { // holes for screws that attach the flare to the body // Number 0 Size, 1/4" Long = thread diameter: 1.6mm, head diameter: 2.75 for (r = [45, 135, 225, 315]) rotate([0, 0, r]) { translate([radius/2, 0, lip/2]) { rotate([0, 90, 0]) { cylinder(r = (1.6 + 0.1)/2, h = radius, $fn = facets); } } } } } // flare to round section translate([0, 0, height]) { difference() { hull() { rounded_octagon(thin_mint, radius); translate([0, 0, transition]) { cylinder(r = top_radius, h = thin_mint, $fn = facets); } } hull() { rounded_octagon(thin_mint, radius - wall); translate([0, 0, transition]) { cylinder(r = top_radius - wall, h = thin_mint, $fn = facets); } } } } // cylindrical stalk translate([0, 0, height + transition]) { difference() { cylinder(r = top_radius, h = stalk_height, $fn = facets); cylinder(r = top_radius - wall, h = stalk_height, $fn = facets); } // add marker for "back of microphone" orientation if (dot == 1) { rotate([0, 0, 90]) { translate([0, top_radius - wall * 2 / 3, stalk_height - top_radius]) { difference() { sphere(r = top_radius / 3, $fn = 32); translate([0, -top_radius + top_radius / 2, 0]) { cube([top_radius, top_radius, top_radius], center = true); } } } } } // close stalk and add holes for cables translate([0, 0, stalk_height - top_radius - wall]) { difference() { cylinder(r = top_radius - wall, h = top_radius + wall, $fn = facets); translate([0, 0, 0]) { sphere(r = top_radius - wall, $fn = facets); } wire_diam = mic_wire_diam + mic_wire_fit; for (r = [0, 90, 180, 270]) rotate([0, 0, r]) { for (t = [0, 1]) { rotate([0, 0, 45 * t]) translate([top_radius - wire_diam - t * wire_diam * 2/3, 0, wall]) { cylinder(r = wire_diam / 2, h = top_radius * 2, $fn = facets); } } } translate([0, 0, wall]) cylinder(r = wire_diam, h = top_radius * 2, $fn = facets); } } } } // flares from the body to a dual cable housing module octa_mount_flare_dual(height, lip, transition, xradius, yradius, corner, top_radius, stalk_height) { // hack to get it to render, fix problem in rounded_block when radius is equal to corner... delta = 0.001; difference() { union() { // bottom rounded box difference() { rounded_block(height, xradius, yradius, corner); rounded_block_relative(height, xradius, yradius, corner, -(2 * wall)); // flange to mount on body rounded_block_relative(lip + 1.00, xradius, yradius, corner, - (wall)); // and make a smooth transition to avoid overhangs translate([0, 0, lip + 1.00]) { hull() { rounded_block_relative(thin_mint, xradius, yradius, corner, - wall); translate([0, 0, 1.0]) { rounded_block_relative(thin_mint, xradius, yradius, corner, - 2 * wall); } } } } // flare to rounded section translate([0, 0, height]) { difference() { hull() { rounded_block(thin_mint, xradius, yradius, corner); translate([0, 0, transition]) { rounded_block(thin_mint, top_radius + wall / 2, top_radius * 2 + wall / 2, top_radius - delta); } } hull() { rounded_block_relative(thin_mint, xradius, yradius, corner, - 2 * wall); translate([0, -top_radius, transition]) { cube([thin_mint, (top_radius) * 2, thin_mint]); } } } } // corner box cable stalk translate([0, 0, height + transition]) { rounded_block(stalk_height, top_radius + wall / 2, top_radius * 2 + wall / 2, top_radius - delta); } } // holes for the cables for (offset = [top_radius - wall/2, -(top_radius - wall/2)]) { translate([0, offset, 0]){ cylinder(r = top_radius - wall, h = height + transition + stalk_height, $fn = facets); } } } } // flare from the body to a dual conector housing // bottom connector holder module tetra_mount_connector_holder(height, radius, inside_radius, sleeve_height, sleeve_radius) { difference() { union() { cylinder(r = radius, h = height, $fn = facets); // add seats for screw heads for (m = [-1, 1]) translate([m * conn_core_holes_w / 2, radius / 2, conn_core_holes_h]) { rotate([90, 0, 0]) { scale([1, 1, 1]) cylinder(r = conn_core_screw_d / 2, h = radius * 1.43, $fn = facets); } } } cylinder(r = inside_radius, h = height, $fn = facets); // transition from thin wall to thick wall at the bottom of connector *cylinder(r1 = radius - wall, r2 = inside_radius, h = 2.0, $fn = facets); // holes for connector core screws for (m = [-1, 1]) translate([m * conn_core_holes_w / 2, - radius / 3, conn_core_holes_h]) { rotate([90, 0, 0]) { cylinder(r = conn_core_holes_d / 2, h = radius, $fn = facets); } } // substract cutout for screw heads for (m = [-1, 1]) translate([m * conn_core_holes_w / 2, - radius + 1.5, conn_core_holes_h]) { rotate([90, 0, 0]) { cylinder(r = conn_core_screw_d / 2, h = 2.0, $fn = facets); } } } // thinner cylinder sits inside connector sleeve translate([0, 0, height]) { difference() { cylinder(r = sleeve_radius, h = sleeve_height, $fn = facets); cylinder(r = inside_radius, h = sleeve_height, $fn = facets); } } } // flare to dual cable connectors module octa_mount_flare_connector(height, lip, transition, radius, top_xradius, top_yradius) { // hack to get it to render, fix problem in rounded_block when radius is equal to corner... delta = 0.001; // bottom rounded box difference() { union() { rounded_octagon_wall(height, radius, 2 * wall); if (render_screw_holes) { // small pedestals for the screws that attach the flare to the body // (number 0 size, 1/4" long = thread diameter: 1.6mm, head diameter: 2.75) for (r = [45, 135, 225, 315]) rotate([0, 0, r]) { translate([radius - wall - 1.75, 0, lip/2]) { rotate([0, 90, 0]) { cylinder(r = 1.5, h = 2 * wall, $fn = facets); } } } } } // flange to mount on body rounded_octagon_wall(lip + 1.00, radius - wall, wall); // and make a smooth transition to avoid overhangs translate([0, 0, lip + 1.00]) { hull() { rounded_octagon_wall(thin_mint, radius - wall, wall); translate([0, 0, 1.0]) { rounded_octagon_wall(thin_mint, radius - 2 * wall, wall); } } } if (render_screw_holes) { // holes for screws that attach the flare to the body // Number 0 Size, 1/4" Long = thread diameter: 1.6mm, head diameter: 2.75 for (r = [45, 135, 225, 315]) rotate([0, 0, r]) { translate([radius/2, 0, lip/2]) { rotate([0, 90, 0]) { cylinder(r = (1.6 + 0.1)/2, h = radius, $fn = facets); } } } } } // flare to rounded section translate([0, 0, height]) { difference() { hull() { rounded_octagon(thin_mint, radius); translate([0, 0, transition]) { rounded_block(thin_mint, top_xradius, top_yradius, top_xradius - delta); } } hull() { rounded_octagon(thin_mint, radius - 2 * wall); translate([0, -top_xradius, transition]) { cube([thin_mint, (top_xradius) * 2, thin_mint]); } } } } } // top conical section that plugs into capsule array module octa_capsule_array_mount(angles) { difference() { union() { difference() { cylinder(h = mount_top_height, r1 = mount_radius + wall, r2 = mount_radius_capsule, $fn = facets); cylinder(h = mount_top_height, r1 = mount_radius, r2 = mount_radius_capsule - 3 * wall * wall, $fn = facets); } // second set of optional "leaves" to get a better mount *difference() { cylinder(h = mount_top_height, r1 = mount_radius + wall, r2 = mount_radius_capsule * 0.8, $fn = facets); cylinder(h = mount_top_height, r1 = mount_radius, r2 = mount_radius_capsule * 0.8 - 1.2 * wall, $fn = facets); } } // indentations that match the four lower capsule holders // add ridge height adjustment translate([0, 0, mount_top_height + (mic_radius - capsule_height) + capsule_height * cos(90 - elev_angle) - 2]) { for (az = angles) { rotate([0, 180 - elev_angle, az + 45]) { translate([0, 0, mic_radius - capsule_height]) { capsule(leg_angles, 0, 1, ridge_wfit, ridge_hfit, 1); } } } } // indentations at the top to open up the array a bit translate([0, 0, mount_top_height + mount_radius_capsule / 8]) { for (rot = [45, 135, -135, -45]) { translate([0, 0, 0]) { rotate([0, 90, rot]) { linear_extrude(height = mount_radius_capsule) { minkowski() { polygon(points = [[0, mount_radius_capsule * 0.35], [0, - mount_radius_capsule * 0.35], [mount_radius_capsule * 2 / 3, 0]]); circle(r = 1.0, $fn = facets); } } } } } } } } //// //// render all the different parts //// // microphone body: flare to capsule array (slips into PCB holder body) // module render_octa_capsule_flare(z_offset) { translate([0, 0, z_offset]) { octa_mount_flare(pcb_hi_clear + pcb_hi_exp, mount_lip, flare_height, octa_pcb_radius, mount_radius + wall, stalk_height, 1); translate([0, 0, pcb_hi_clear + pcb_hi_exp + flare_height + stalk_height]) { octa_capsule_array_mount([45, 135, -45, -135]); } } } // microphone body: main body, holds printed circuit boards // octa_pcb_mount_height = pcb_length - pcb_low_exp - pcb_hi_exp; octa_pcb_radius = radial_pcb_offset + pcb_width/2 + 5 * wall; module render_octa_pcb_mount(z_offset, showint) { translate([0, 0, z_offset]) { octa_mount_body(octa_pcb_mount_height, octa_pcb_radius, mount_lip, mount_lip, 0); // add ccrma logo rotate([0, 0, -90 + 22.5]) { translate([0, -(octa_pcb_radius - 3.5), octa_pcb_mount_height / 2]) { rotate([90, 270, 0]) { logo_scale = 1 / 2.4; scale([logo_scale, logo_scale, 1.0]) { ccrma_logo(1.65); } } } } } } // microphone body: flare to microphone cable (slips into PCB holder body) // module render_octa_cable_flare(z_offset, flip) { translate([0, 0, z_offset]) { octa_mount_flare_dual(pcb_low_clear + pcb_low_exp, mount_lip, 20, box_radius + wall, box_radius * 2 - wall, mount_corner, cable_diam / 2 + wall, 10, 0); } } // microphone body: flare to dual cable connectors (slips into PCB holder body) // module render_octa_connector_flare(z_offset, flip) { conn_offset = 2.0; conn_wall = conn_core_o_diam / 2 - conn_core_diam / 2; translate([0, 0, z_offset]) { difference() { union() { octa_mount_flare_connector(pcb_low_clear + pcb_low_exp, mount_lip, 20, octa_pcb_radius, conn_core_o_diam / 2, conn_core_o_diam + conn_offset); for (m = [0, 1]) mirror([0, m, 0]) translate([0, conn_core_o_diam / 2 + conn_offset, pcb_low_clear + pcb_low_exp + 20]) { // add two connectors rotate([0, 0, -90]) { tetra_mount_connector_holder(conn_core_sleeve, conn_core_o_diam / 2, conn_core_diam / 2, conn_core_overlap, conn_core_s_diam / 2); } // add wall in between the two connectors translate([- 2 * wall, - (conn_core_o_diam / 2 + conn_offset), 0]) { cube([4 * wall, conn_offset + wall, 10]); } } } // redo the hole in the connector holder so that it drills into the top of the flare for (m = [0, 1]) mirror([0, m, 0]) translate([0, conn_core_o_diam / 2 + conn_offset, 0]) { cylinder(r = conn_core_diam / 2, h = 100, $fn = facets); } } } } // microphone body: render all parts with a vertical separation // module render_octa_body(z_offset, spread, showint) { rotate([0, 180, 0]) { render_octa_connector_flare(0); } lippy = spread - mount_lip; render_octa_pcb_mount(lippy, showint); render_octa_capsule_flare(octa_pcb_mount_height + 2 * lippy); } // microphone: render the full assembly with vertical separation between components // module render_octa_microphone(z_offset, spread) { render_octa_body(z_offset, spread); lippy = spread - mount_lip; render_octa_capsule_array(z_offset + octa_pcb_mount_height + mount_top_height + flare_height + stalk_height + pcb_hi_clear + pcb_hi_exp + 2 * lippy + spread + mic_radius); } // microphone: render the full assembly with vertical separation between components // cut out half of the assembly so that we can see the inside // module render_octa_microphone_cutout(z_offset, spread) { difference() { render_octa_microphone(z_offset, spread); // a cube that blots out 1/4 of the microphone rotate([0, 0, 90]) { translate([0, 0, -50]) { cube([50, 100, 650]); } } } } // shock mount: microphone clip on stand mount // module render_octa_shock_mount_stand(z_offset) { translate([z_offset]) { shock_mount_stand(mic_mount_height, mount_wall, mic_mount_wall); } } // shock mount: external ring // module render_octa_shock_mount_external_ring(z_offset) { translate([0, 0, z_offset]) { shock_mount_external_ring(ring_height, box_radius + wall, box_radius * 2 - wall, mount_corner, main_radius_inc, 0); } } // shock mount: bottom internal ring // module render_octa_shock_mount_internal_ring_bot(z_offset) { translate([0, 0, z_offset]) { shock_mount_internal_ring(ring_height, box_radius + wall, box_radius * 2 - wall, mount_corner, internal_ring_gap, 1); } } // shock mount: top internal ring // module render_octa_shock_mount_internal_ring_top(z_offset) { translate([0, 0, z_offset]) { shock_mount_internal_ring(ring_height, box_radius + wall, box_radius * 2 - wall, mount_corner, internal_ring_gap, 0); } } // shock mount: all four internal ring connectors // module render_octa_shock_mount_ring_connectors(offset) { for (o = [0, 1, 2, 3]) { translate([-18, (10 + offset) * o, 0]) { shock_mount_connector(ring_sep, 4, connector_w, connector_d, 0.1); } } } // shock mount: render all parts // module render_octa_shock_mount(z_offset) { // internal rings translate([0, 0, z_offset + ring_sep / 2]) { render_octa_shock_mount_internal_ring_top(0); rotate([0, 180, 0]) { render_octa_shock_mount_internal_ring_bot(ring_sep + 2); } // insert the connecting rods for (r = [0, 90, 180, 270]) { rotate([0, 0, r]) { translate([((r % 180) ? box_radius * 2 : box_radius) + 3 * wall + internal_ring_gap, 0, -1]) { rotate([0, 90, 0]) { translate([-4, -5, 1]) { shock_mount_connector(ring_sep, 4, connector_w, connector_d, 0.1); } } } } } } // external ring translate([0, 0, z_offset - ring_height / 4]) { render_octa_shock_mount_external_ring(0); } // mount to stand translate([box_radius + mount_corner + ring_wall + ring_arm_gap + 8 + ring_wall / 2 + 4, 0, -(mic_mount_height + mic_mount_radius + ring_height / 4)]) { render_octa_shock_mount_stand(0); } }