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Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

The New Hotness

  • Tour Easy: Anker 20K V2 USB Power Bank

    After five years, it’s time to replace the Anker 13000 mA·hr USB power banks / chargers I used with the M20 cameras and then the C100 cameras:

    SJCAM M20 Mount - Tour Easy side view
    SJCAM M20 Mount – Tour Easy side view

    The Anker 325 20K V2 power bank is considerably chunkier, as befits its 20,000 mA·hr cell capacity (although the fine print says 12,500 mA·hr output):

    Anker 20K V2 Power Bank - installed
    Anker 20K V2 Power Bank – installed

    The white tape stripe on the top marks the USB port on the end to reduce the fumbling involved in an out-of-sight socket. There’s also a USB-C port on that end for both charging the pack and powering other devices.

    The new mounting cradle descends directly from the 13000 cradle:

    Anker 325 20KV2 Power Bank - slicer preview
    Anker 325 20KV2 Power Bank – slicer preview

    The model includes a projection of the battery on the XY plane for export to an SVG file suitable for laser-cutting an EVA foam pad to cushion the bumps.

    The OpenSCAD source code as a GitHub Gist:

    // Anker PowerCore 325 20K V2 Power Bank
    // Ed Nisley – KE4ZNU
    // 2024-07
    /* [Layout Options] */
    Layout = "Show"; // [Show,Build]
    Part = "Cradle"; // [Cradle,Battery,Pad]
    /* [Extrusion Parameters] */
    ThreadWidth = 0.40;
    ThreadThick = 0.25;
    HoleWindage = 0.2;
    Protrusion = 0.1;
    //—–
    // Dimensions
    /* [Hidden] */
    ID = 0;
    OD = 1;
    LENGTH = 2;
    EmbossDepth = 2*ThreadThick + Protrusion; // recess depth + Protrusion beyond surface
    DebossHeight = EmbossDepth; // text height + Protrusion into part
    Projection = 10; // stick-out to punch through shell sides & suchlike
    FadeColor = "Green";
    FadeAlpha = 0.25;
    //—–
    // Useful routines
    function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit);
    module PolyCyl(Dia,Height,ForceSides=0) { // based on nophead's polyholes
    Sides = (ForceSides != 0) ? ForceSides : (ceil(Dia) + 2);
    FixDia = Dia / cos(180/Sides);
    cylinder(r=(FixDia + HoleWindage)/2,
    h=Height,
    $fn=Sides);
    }
    //—–
    // Battery
    // Based on Anker PowerCore 325, simplified shapes
    // Includes port punchouts
    Battery = [162.0+0.5,81.5+0.5,24.0]; // X=length, Y=max, Z=max
    module BatteryShape(Jacks = true) {
    USB = [[Projection,20,12],[Projection,18,10]]; // clearance around USB output jacks
    USBOffset = [[0,20.0,0],[0,62.5,0]]; // from -Y edge to center of jack, Z centered
    BatteryRad = 7.0; // corner rounding radius
    BatterySides = 2*3*4;
    hull()
    for (i=[-1,1], j=[-1,1])
    translate([i*(Battery.x/2 – BatteryRad),
    j*(Battery.y/2 – BatteryRad),
    0])
    cylinder(r=BatteryRad,h=Battery.z,$fn=BatterySides,center=true);
    if (Jacks)
    for (i=[0,len(USB)-1])
    translate([(Battery.x + USB[i].x)/2 – Protrusion,-Battery.y/2 + USBOffset[i].y,0])
    cube(USB[i],center=true);
    }
    //—–
    // Battery cradle
    RackWidth = 90.0; // flat width between rack rails
    CradleWall = [4.0,4.0,3.0]; // wall thickness
    CradleRadius = 2.0; // corner rounding
    CradlePad = 1.0; // cushion on battery bottom
    BatteryBase = CradleWall.z + CradlePad; // actual bottom surface of battery
    CradleOA = [Battery.x + 2*CradleWall.x,
    min((Battery.y + 2*CradleWall.y),RackWidth),
    BatteryBase + Battery.z/2];
    echo(str("Cradle OA: ",CradleOA));
    module Cradle() {
    difference() {
    hull()
    for (i=[-1,1], j=[-1,1]) { // box with tidy rounded corners
    translate([i*(CradleOA.x/2 – CradleRadius),
    j*(CradleOA.y/2 – CradleRadius),
    1*(CradleOA.z – CradleRadius)])
    sphere(r=CradleRadius,$fn=6);
    translate([i*(CradleOA.x/2 – CradleRadius),
    j*(CradleOA.y/2 – CradleRadius),
    0*(CradleOA.z/2 – CradleRadius)])
    cylinder(r=CradleRadius,h=CradleOA.z/2,$fn=6);
    }
    translate([0,0,Battery.z/2 + BatteryBase]) // minus the battery
    minkowski(convexity=3) { // … slightly embiggened
    BatteryShape();
    cube(2*CradlePad,center=true);
    }
    translate([0,0,CradleWall.z – ThreadThick + Protrusion/2]) // recess top legend
    cube([55,20,EmbossDepth],center=true);
    translate([0,0,(EmbossDepth – Protrusion)/2]) // recess bottom legend
    cube([70,15,EmbossDepth],center=true);
    }
    translate([0,4.0,CradleWall.z – DebossHeight – Protrusion])
    linear_extrude(height=DebossHeight,convexity=20)
    text(text="PowerCore",size=6,spacing=1.20,
    font="Arial:style:Bold",halign="center",valign="center");
    translate([0,-4.0,CradleWall.z – DebossHeight – Protrusion])
    linear_extrude(height=DebossHeight,convexity=20)
    text(text="20K V2",size=6,spacing=1.20,
    font="Arial:style:Bold",halign="center",valign="center");
    linear_extrude(height=DebossHeight,convexity=20)
    mirror([0,1,0])
    text(text="KE4ZNU",size=10,spacing=1.20,
    font="Arial:style:Bold",halign="center",valign="center");
    }
    //—–
    // Build things
    // Layouts for design & tweaking
    if (Layout == "Show")
    if (Part == "Battery")
    BatteryShape();
    else if (Part == "Cradle") {
    Cradle();
    translate([0,0,Battery.z/2 + CradleWall.z])
    color(FadeColor,FadeAlpha)
    BatteryShape();
    }
    else if (Part == "Pad")
    linear_extrude(height=CradlePad)
    projection(cut=true)
    BatteryShape(Jacks = false);
    // Build layouts for top-level parts
    if (Layout == "Build") {
    if (Part == "Cradle")
    Cradle();
    if (Part == "Pad")
    projection(cut=true)
    BatteryShape(Jacks = false);
    }