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

  • Glass Tiles: 2×2 Matrix

    Start with a single cell holding a glass tile over a WS2812 RGB LED:

    Glass Tile - 1x1 cell test - purple phase
    Glass Tile – 1×1 cell test – purple phase

    A bit of OpenSCAD tinkering produces a simple 2×2 array with square interiors as a test piece:

    Glass Tile - 2x2 - PETG strings
    Glass Tile – 2×2 – PETG strings

    The excessive stringing and the booger in the upper-left cell come from absurdly thin infill tucked into the too-thin walls; Slic3r doesn’t (seem to) have a “minimum infill width” setting and it’ll desperately try to fit infill between two nearly adjacent perimeter threads.

    The little support spiders under the LED PCB recesses snapped right out, though, so I got that part right:

    Glass Tile - 2x2 - support spiders
    Glass Tile – 2×2 – support spiders

    The perimeter threads around the LED aperture aren’t quite fused, because it was only one layer thick and that’s not enough.

    A quick test with two LEDs showed the white PETG let far too much light bleed between the cells, which was no surprise from the single cell test piece.

    Fortunately, it’s all parametric, so a bit more tinkering produced a slightly chunkier matrix with a base for an Arduino Nano and M3 threaded brass inserts for the screws holding it together:

    Glass Tile Frame - 2x2 - Arduino Nano base - solid model
    Glass Tile Frame – 2×2 – Arduino Nano base – solid model

    Those two parts require about three hours of printing, much faster than I could produce them by milling pockets into aluminum or black acrylic slabs, and came out with minimal stringing.

    A little cleanup, some epoxy work, and a few dabs of solder later:

    Glass Tile - 2x2 - Arduino wiring
    Glass Tile – 2×2 – Arduino wiring

    An initial lamp test showed the white-ish glass tiles aren’t all quite the same color:

    Glass Tile - 2x2 - white color variation
    Glass Tile – 2×2 – white color variation

    I thought it was an LED color variation, too, but the slightly blue tint in the lower left corner followed the tile.

    The blurred horizontal strip across the middle is adhesive tape holding the tiles in place; I was reluctant to glue them in before being sure this whole thing would work. A peek into the future, though, shows it’s got potential:

    Glass Tile - 2x2 - first two units
    Glass Tile – 2×2 – first two units

    They do give off a definite Windows logo vibe, don’t they?

    The OpenSCAD source code as a GitHub Gist:

    // Illuminated Tile Grid
    // Ed Nisley – KE4ZNU
    // 2020-05
    /* [Configuration] */
    Layout = "Build"; // [Cell,CellArray,MCU,Base,Show,Build]
    Shape = "Square"; // [Square, Pyramid, Cone]
    Cells = [2,2];
    CellDepth = 15.0;
    Support = true;
    Inserts = true;
    /* [Hidden] */
    ThreadThick = 0.25;
    ThreadWidth = 0.40;
    HoleWindage = 0.2;
    function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit);
    Protrusion = 0.1; // make holes end cleanly
    ID = 0;
    OD = 1;
    LENGTH = 2;
    Tile = [25.0 + 0.1,25.0 + 0.1,4.0];
    WallThick = 3*ThreadWidth;
    Flange = [4*ThreadWidth,4*ThreadWidth,0]; // ridge supporting tile
    Separator = [3*ThreadWidth,3*ThreadWidth,Tile.z – 1]; // between tiles
    Screw = [3.0,6.0,3.5]; // M3 SHCS, OD=head, LENGTH=head
    Insert = [3.0,4.2,8.0]; // threaded brass insert
    PCB = [15.0,8.0,2.5];
    LED = [5.0 + 2*HoleWindage,5.0 + 2*HoleWindage,1.0];
    LEDOffset = [0.0,(PCB.y – LED.y)/2 – 0.5,0.0]; // slight offset from +Y PCB edge
    CellOAL = [Tile.x,Tile.y,0] + Separator + [0,0,CellDepth] + [0,0,WallThick] + [0,0,PCB.z];
    ArrayOAL = [Cells.x*CellOAL.x,Cells.y*CellOAL.y,CellOAL.z]; // just the LED cells
    BlockOAL = ArrayOAL + [2*WallThick,2*WallThick,0]; // LED cells + exterior wall
    echo(str("Block OAL: ",BlockOAL));
    InsertOC = ArrayOAL – [Insert[OD],Insert[OD],0] – [2*WallThick,2*WallThick,0];
    echo(str("Insert OC: ",InsertOC));
    TapeThick = 1.0;
    Arduino = [44.0,18.0,8.0 + TapeThick]; // Arduino Nano to top of USB Mini-B plug
    USBPlug = [15.0,11.0,8.5]; // USB Mini-B plug insulator
    USBOffset = [0,0,5.5]; // offset from PCB base
    WiringBay = [BlockOAL.x – 4*WallThick,38.0,3.0];
    PlateOAL = [BlockOAL.x,BlockOAL.y,WallThick + Arduino.z + WiringBay.z];
    echo(str("Base Plate: ",PlateOAL));
    //————————
    module PolyCyl(Dia,Height,ForceSides=0) { // based on nophead's polyholes
    Sides = (ForceSides != 0) ? ForceSides : (ceil(Dia) + 2);
    FixDia = Dia / cos(180/Sides);
    cylinder(d=(FixDia + HoleWindage),h=Height,$fn=Sides);
    }
    //———————–
    // Base and optics in single tile
    module LEDCone() {
    hull() {
    translate([0,0,CellDepth + Tile.z/2])
    cube(Tile – [Flange.x,Flange.y,0],center=true);
    if (Shape == "Square") {
    translate([0,0,LED.z/2])
    cube([Tile.x,Tile.y,LED.z] – [Flange.x,Flange.y,0],center=true);
    }
    else if (Shape == "Pyramid") {
    translate([0,0,LED.z/2])
    cube(LED,center=true);
    }
    else if (Shape == "Cone") {
    translate([0,0,LED.z/2])
    cylinder(d=1.5*LED.x,h=LED.z,center=true);
    }
    else {
    echo(str("Whoopsie! Invalid Shape: ",Shape));
    cube(5);
    }
    }
    }
    // One complete LED cell
    module LEDCell() {
    difference() {
    translate([0,0,CellOAL.z/2])
    cube(CellOAL,center=true);
    translate([0,0,CellOAL.z – Separator.z + Tile.z/2])
    cube(Tile,center=true);
    translate([0,0,PCB.z + WallThick])
    LEDCone();
    cube([LED.x,LED.y,CellOAL.z],center=true);
    translate(-LEDOffset + [0,0,PCB.z/2 – Protrusion/2])
    cube(PCB + [0,0,Protrusion],center=true);
    }
    if (Support)
    color("Yellow") render()
    translate(-LEDOffset) {
    // translate([0,0,ThreadThick/2])
    // cube([PCB.x – 2*ThreadWidth,PCB.y – 2*ThreadWidth,ThreadThick],center=true);
    intersection() {
    translate([0,0,(PCB.z – ThreadThick)/2])
    cube([PCB.x – 2*ThreadWidth,PCB.y – 2*ThreadWidth,PCB.z – ThreadThick],center=true);
    union() { for (a=[0:22.5:359])
    rotate(a)
    translate([PCB.x/2,0,PCB.z/2])
    cube([PCB.x,2*ThreadWidth,PCB.z],center=true); }
    }
    }
    }
    // The whole array of cells
    module CellArray() {
    difference() {
    union() {
    translate([CellOAL.x/2 – Cells.x*CellOAL.x/2,CellOAL.y/2 – Cells.y*CellOAL.y/2,0])
    for (i=[0:Cells.x – 1], j=[0:Cells.y – 1])
    translate([i*CellOAL.x,j*CellOAL.y,0])
    LEDCell();
    if (Inserts) // bosses
    for (i=[-1,1], j=[-1,1])
    translate([i*InsertOC.x/2,j*InsertOC.y/2,0])
    rotate(180/8)
    cylinder(d=Insert[OD] + 3*WallThick,h=Insert[LENGTH],$fn=8);
    }
    if (Inserts) // holes
    for (i=[-1,1], j=[-1,1])
    translate([i*InsertOC.x/2,j*InsertOC.y/2,-Protrusion])
    rotate(180/8)
    PolyCyl(Insert[OD],Insert[LENGTH] + WallThick + Protrusion,8);
    }
    difference() {
    translate([0,0,CellOAL.z/2])
    cube(BlockOAL,center=true);
    translate([0,0,CellOAL.z])
    cube(ArrayOAL + [0,0,2*CellOAL.z],center=true);
    }
    }
    // Arduino bounding box
    // Origin at center bottom of PCB
    module Controller() {
    union() {
    translate([0,0,Arduino.z/2])
    cube(Arduino,center=true);
    translate([Arduino.x/2 – Protrusion,-USBPlug.y/2,USBOffset.z + TapeThick – USBPlug.z/2])
    cube(USBPlug + [Protrusion,0,0],center=false);
    }
    }
    // Baseplate
    module BasePlate() {
    difference() {
    translate([0,0,PlateOAL.z/2])
    cube(PlateOAL,center=true);
    translate([0,0,WallThick])
    Controller();
    translate([0,0,WallThick + PlateOAL.z/2])
    cube([Arduino.x – 2*2.0,WiringBay.y,PlateOAL.z],center=true);
    translate([0,0,PlateOAL.z – WiringBay.z + WiringBay.z/2])
    cube(WiringBay + [0,0,2*Protrusion],center=true);
    for (i=[-1,1], j=[-1,1])
    translate([i*InsertOC.x/2,j*InsertOC.y/2,-Protrusion])
    rotate(180/8) {
    PolyCyl(Screw[ID],2*PlateOAL.z,8);
    PolyCyl(Screw[OD],Screw[LENGTH] + 4*ThreadThick + Protrusion,8);
    }
    translate([0,0,ThreadThick-Protrusion])
    cube([17.0,45,2*ThreadThick],center=true);
    }
    linear_extrude(height=2*ThreadWidth + Protrusion) {
    translate([1,0,-Protrusion])
    rotate(-90) mirror([1,0,0])
    text(text="Ed Nisley",size=6,font="Arial:style:Bold",halign="center");
    translate([-6.5,0,-Protrusion])
    rotate(-90) mirror([1,0,0])
    text(text="softsolder.com",size=4.5,font="Arial:style:Bold",halign="center");
    }
    if (Support)
    color("Yellow")
    for (i=[-1,1], j=[-1,1])
    translate([i*InsertOC.x/2,j*InsertOC.y/2,0])
    for (a=[0:45:135])
    rotate(a)
    translate([0,0,(Screw[LENGTH] – ThreadThick)/2])
    cube([Screw[OD] – 2*ThreadWidth,2*ThreadWidth,Screw[LENGTH] – ThreadThick],center=true);
    }
    //———————–
    // Build things
    if (Layout == "Cell")
    LEDCell();
    else if (Layout == "CellArray")
    CellArray();
    else if (Layout == "MCU")
    Controller();
    else if (Layout == "Base")
    BasePlate();
    else if (Layout == "Show") {
    translate([0,0,PlateOAL.z + 10])
    CellArray();
    BasePlate();
    }
    else if (Layout == "Build") {
    translate([0,0.6*BlockOAL.y,0])
    CellArray();
    translate([0,-0.6*BlockOAL.y,0])
    rotate(90)
    BasePlate();
    }