The Smell of Molten Projects in the Morning

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

  • Improved Sony AS30V Helmet Mount Adapter Plate

    Last week a wind gust blew my Tour Easy over while resting on its kickstand at Mary’s garden; I rarely depend on the kickstand for that very reason, but some days are like that. Anyhow, the mount for the Sony AS30V helmet camera did exactly what it should by releasing the camera, rather than grinding it into the ground.

    Calling it a “mount” may be overstating the case:

    Sony HDR-AS30V camera on bike helmet - inverted
    Sony HDR-AS30V camera on bike helmet – inverted

    I was still using that helmet, albeit with a better mirror mount, but it was getting rather crusty and the hook-n-loop straps were definitely sun-faded, so I built a better mount with an adapter plate matching a new-old-stock helmet from the stash:

    Sony AS30V Helmet mount - side view
    Sony AS30V Helmet mount – side view

    The white slab atop the helmet curves to match the helmet contour, with the ridge fitting into the vent slot:

    AS30 helmet mount - solid model - show view
    AS30 helmet mount – solid model – show view

    OK, the helmet isn’t orange, but you get the idea. The sphere has a 153 mm radius, calculated from the Official Sony helmet mount’s bottom curve, minus a ring shaping the central groove:

    AS30 helmet mount - solid model - tab ring
    AS30 helmet mount – solid model – tab ring

    This upside-down view shows the interesting parts:

    AS30 helmet mount - solid model
    AS30 helmet mount – solid model

    The flat side sticks to the camera’s holder with a custom-cut sheet of craft adhesive shaped like this:

    AS30 helmet mount - glue
    AS30 helmet mount – glue

    The overall outline of those things comes from a scan of the bottom of the Sony camera holder, passed through Inkscape and LightBurn to generate the curves:

    AS30 Baseplate scan
    AS30 Baseplate scan

    The large notches in the sides pass hook-n-loop straps intended to break away when the helmet hits the ground again. The front tunnel (of two, because symmetry) passes a cable tie preventing the camera from parting company with the mount during normal riding and holding the yellow latch in the Locked position:

    Sony AS30V Helmet mount - rear view
    Sony AS30V Helmet mount – rear view

    It is just barely possible to slide the cable tie over the front of the camera to release the latch.

    The camera rides upside-down to protect the lens from scuffs and scrapes. Fortunately, there’s a setting to invert the picture.

    For completeness, the front view:

    Sony AS30V Helmet mount - front view
    Sony AS30V Helmet mount – front view

    The furry patch covers the microphone pores to kill (most of) the wind noise.

    The sharp ventral angle matches the helmet’s midline ridge in the back, but obviously isn’t needed over the vent hole in the front. I decided to not bother making a comprehensive model of the hole, not least because I didn’t really know the camera’s exact front-to-back location.

    Works fine where it sits, though:

    Burnett Signal Timing - 2025-04-23
    Burnett Signal Timing – 2025-04-23

    NYSDOT’s signal timing at Burnett Blvd and Rt 55 remains bicycle-hostile, same as it ever was.

    The OpenSCAD source code and baseplate shape as a GitHub Gist:

    // Sony AS30 helmet mount
    // Ed Nisley – KE4ZNU
    // 2025-04-20
    include <BOSL2/std.scad>
    Layout = "Show"; // [Show,Build,Ball,Tab,Glue]
    Gap = 5; // [0:5:20]
    /* [Hidden] */
    HoleWindage = 0.2;
    Protrusion = 0.1;
    WallThick = 1.0; // enough stiffness against flat pad
    HelmetRadius = 153.0; // from chord equation on curved pad = magic number
    Groove = [30.0,100,3.0,]; // roughly the groove along helmet midline
    Pad = [38,53,10]; // baseplate size, thick enough without fancy trig
    Strap = [3.0,15.0,10*Pad.z]; // hook-n-loop strap holes, double-thick
    Tie = [100,6.0,2.0 + Protrusion]; // cable tie around camera
    TieOffset = 14.0; // … from end of pad
    $fn=96;
    //———-
    // Define shapes
    module Ball() {
    difference() {
    sphere(r=HelmetRadius);
    Tab();
    }
    }
    // Rough approximation of the helmet groove
    module Tab() {
    m = 2.0; // roughly the chord height beyond the tab
    rotate_extrude(convexity=10) {
    right(HelmetRadius)
    zrot(180)
    polygon([
    [0,0],
    [0,Groove.x/2],[Groove.z + m,Groove.x/2],[m,0],
    [Groove.z + m,-Groove.x/2],[0,-Groove.x/2],
    [0,0]
    ],convexity=10);
    }
    }
    // Baseplate with all the cutouts
    module BasePlate() {
    difference() {
    linear_extrude(height=Pad.z,convexity=10)
    import("AS30 Baseplate layout.svg",layer="Baseplate");
    up(WallThick + HelmetRadius)
    yrot(90)
    Ball();
    for (i = [-1,1]) // strap clearance at edge of helmet hole
    right(i*Groove.x/2)
    cube([(Pad.x – Groove.x)/2,Strap.y,Strap.z],center=true);
    for (i = [-1,1]) // cut through edge of pad
    right(i*Pad.x/2)
    cube([(Pad.x – Groove.x),Strap.y,Strap.z],center=true);
    for (j = [-1,1])
    fwd(j*(Pad.y/2 – TieOffset)) up(WallThick)
    cuboid(Tie,anchor=BOTTOM);
    }
    }
    //———-
    // Build things
    if (Layout == "Glue")
    projection(cut=true)
    BasePlate();
    if (Layout == "Tab")
    Tab();
    if (Layout == "Show") {
    xrot(180)
    BasePlate();
    down(WallThick + HelmetRadius + Gap)
    yrot(90)
    color("Orange",0.75) Ball();
    }
    if (Layout == "Build")
    BasePlate();
    if (Layout == "Ball")
    Ball();
    view raw AS30 helmet mount.scad hosted with ❤ by GitHub
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    view raw gistfile1.txt hosted with ❤ by GitHub