Cartridge - 20x102mm outline.svg

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!-- Created with Inkscape (http://www.inkscape.org/) -->

<svg
   width="11in"
   height="8.5in"
   viewBox="0 0 279.40056 215.90043"
   version="1.1"
   id="SVGRoot"
   inkscape:version="1.4.1 (93de688d07, 2025-03-30)"
   sodipodi:docname="Cartridge - 20x102mm outline.svg"
   xml:space="preserve"
   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
   xmlns:xlink="http://www.w3.org/1999/xlink"
   xmlns="http://www.w3.org/2000/svg"
   xmlns:svg="http://www.w3.org/2000/svg"
   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:cc="http://creativecommons.org/ns#"><sodipodi:namedview
     id="namedview7"
     pagecolor="#ffffff"
     bordercolor="#0000ff"
     borderopacity="1"
     inkscape:pageshadow="0"
     inkscape:pageopacity="0"
     inkscape:pagecheckerboard="1"
     inkscape:document-units="mm"
     showgrid="true"
     units="mm"
     gridtolerance="9.9"
     guidetolerance="10.4"
     inkscape:snap-perpendicular="true"
     inkscape:snap-tangential="true"
     width="700mm"
     borderlayer="false"
     inkscape:showpageshadow="true"
     viewbox-width="700"
     guidecolor="#ff00e3"
     guideopacity="0.49803922"
     inkscape:zoom="1.8494139"
     inkscape:cx="279.27766"
     inkscape:cy="262.5156"
     inkscape:window-width="1780"
     inkscape:window-height="1091"
     inkscape:window-x="0"
     inkscape:window-y="0"
     inkscape:window-maximized="0"
     inkscape:current-layer="layer2"
     objecttolerance="31"
     inkscape:deskcolor="#d1d1d1"
     showguides="true"><inkscape:grid
       type="xygrid"
       id="grid9"
       units="mm"
       spacingx="5"
       spacingy="5"
       dotted="false"
       empspacing="2"
       originx="148.5"
       originy="127.29919"
       color="#ff0000"
       opacity="0.18431373"
       empcolor="#4040ff"
       empopacity="0.49411765"
       visible="true" /></sodipodi:namedview><defs
     id="defs2" /><image
     width="124.88358"
     height="40.724747"
     preserveAspectRatio="none"
     xlink:href="../Cartridge%20-%2020x103mm%20outline.jpg"
     id="image1"
     x="22.287945"
     y="151.96129" /><g
     inkscape:label="Cartridge Outline"
     inkscape:groupmode="layer"
     id="layer1"
     transform="translate(0,5.4354331)"><path
       style="fill:none;fill-rule:evenodd;stroke:#ff0000;stroke-width:0.2;stroke-linejoin:round;stroke-dasharray:none;stroke-opacity:1"
       d="m 37.769048,157.1879 6.929546,-0.12646 c 3.218826,0.0228 8.830866,-2.80879 9.992216,-2.76278 l 76.95589,-0.98018 1.78297,1.78296 h 2.81987 v -2.01058 h 1.97264 l 1.00877,0.2703 v 29.1781 l -0.70149,0.7015 h -2.20405 v -1.97648 h -2.79595 l -1.75067,1.75067 -76.86291,-1.01725 c -0.87047,0.0302 -7.10576,-3.20305 -10.099511,-3.01749 l -6.971449,0.23553 z"
       id="path1"
       sodipodi:nodetypes="ccccccccccccccccccc" /></g><metadata
     id="metadata11"><rdf:RDF><cc:Work
         rdf:about=""><cc:license
           rdf:resource="http://creativecommons.org/licenses/by-nc-sa/4.0/" /></cc:Work><cc:License
         rdf:about="http://creativecommons.org/licenses/by-nc-sa/4.0/"><cc:permits
           rdf:resource="http://creativecommons.org/ns#Reproduction" /><cc:permits
           rdf:resource="http://creativecommons.org/ns#Distribution" /><cc:requires
           rdf:resource="http://creativecommons.org/ns#Notice" /><cc:requires
           rdf:resource="http://creativecommons.org/ns#Attribution" /><cc:prohibits
           rdf:resource="http://creativecommons.org/ns#CommercialUse" /><cc:permits
           rdf:resource="http://creativecommons.org/ns#DerivativeWorks" /><cc:requires
           rdf:resource="http://creativecommons.org/ns#ShareAlike" /></cc:License></rdf:RDF></metadata><g
     inkscape:groupmode="layer"
     id="layer2"
     inkscape:label="Cartridge Aligned Half"><path
       style="fill:none;fill-rule:evenodd;stroke:#ff0000;stroke-width:0.2;stroke-linejoin:round;stroke-dasharray:none;stroke-opacity:1"
       d="m 0,109.0648 h 10.978022 l 0.126348,6.86782 c -0.0228,3.21882 2.80879,8.83086 2.76278,9.99221 l 0.98019,76.95589 -1.78297,1.78297 v 2.81987 h 2.01058 v 1.97264 L 14.80454,210.46497 0,210.465 Z"
       id="path2"
       sodipodi:nodetypes="cccccccccccc"
       transform="translate(0,5.4354331)"
       inkscape:label="Cartridge Half" /></g></svg>

Cartridge 20x102mm.scad

// 20x102mm cartridge
// Ed Nisley - KE4ZNU
// 2025-05-18

include <BOSL2/std.scad>

Layout = "Show";              // [Show,Build]

Powder = true;                // build internal void

/* [Hidden] */

ID = 0;
OD = 1;
LENGTH = 2;

HoleWindage = 0.2;
Protrusion = 0.1;
NumSides = 3*3*4;

$fn = NumSides;

CartridgeOA = [21.0,29.5,101.4];       // must match SVG pretty closely

PrimerOA = [2.0,8.0,2.0];

CapsuleTip = [7.5,7.5,5.0];
Capsule = [7.5,18.8 + HoleWindage,83];
SeatingDepth = 25.0;

Void = [CartridgeOA[ID]- 4.0,CartridgeOA[OD]- 4.0,CartridgeOA[LENGTH] - SeatingDepth - 4*PrimerOA[LENGTH]];

//----------
// Define shapes

module Cartridge() {

  difference() {
    rotate_extrude()
      import("Cartridge - 20x102mm outline.svg",layer="Cartridge Aligned Half");
    up(PrimerOA[LENGTH])
      cyl(PrimerOA[LENGTH] + Protrusion,d=PrimerOA[OD],anchor=TOP);
    up(CartridgeOA[LENGTH] + CapsuleTip[LENGTH])
      cyl(SeatingDepth,d=Capsule[OD],anchor=TOP);
    up(CartridgeOA[LENGTH] - SeatingDepth)
      cyl(Void[LENGTH],d=CapsuleTip[OD],anchor=BOTTOM);
    if (Powder) {
      up(Void[LENGTH]/2)
        cyl(Void[LENGTH],d=CapsuleTip[OD],anchor=BOTTOM);
      up(2*PrimerOA[LENGTH])
        cyl(Void[LENGTH],d=Void[OD],rounding=Void[OD]/2,anchor=BOTTOM);
      down(Protrusion)
        cyl(Void[LENGTH],d=PrimerOA[ID],anchor=BOTTOM);
    }
  }

}

module Primer() {
  difference() {
    cyl(PrimerOA[LENGTH] - Protrusion,d=PrimerOA[OD] - HoleWindage,anchor=BOTTOM);
    up(PrimerOA[LENGTH])
      spheroid(d=PrimerOA[ID]);
  }
}


//----------
// Build things

if (Layout == "Show")
//render()
  difference() {
    Cartridge();
    cuboid(3*CartridgeOA[LENGTH],anchor=LEFT+BACK);
}

if (Layout == "Build") {
  Cartridge();
  right(CartridgeOA[OD])
    Primer();
}

More details on my blog at https://softsolder.com/2025/05/19/3d-printed-20102mm-cartridge/