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

  • Under-cabinet Lamp Brackets

    These blocky brackets hold a pair of LED light strips in the recess under our 1955-era kitchen cabinets, to let the light cover the entire counter:

    Kitchen Light Bracket
    Kitchen Light Bracket

    The large holes are for drywall screws into the cabinet, the smaller ones for 2.5 mm SHCS holding the strips to the brackets. I drilled those little holes out and installed 4-40 brass inserts; this being a one-off installation, the source code doesn’t include that change.

    There’s not much to see after they’re installed:

    Under-cabinet light bracket - center joiner
    Under-cabinet light bracket – center joiner

    I’d hoped to swap the ends of the strip to power it from the right end, but the guts aren’t symmetric and you can’t just flip it end-for-end:

    eShine LED Under-cabinet light - disassembled
    eShine LED Under-cabinet light – disassembled

    That’s an add-on unit without the IR proximity sensor circuitry and power switch, but with the same overall layout. You take it apart by pressing the obvious latch on one of the endcaps, then gently prying the plastic away from the aluminum extrusion, taking care not to wreck the coaxial socket. Reassemble in reverse order.

    The OpenSCAD source code as a GitHub Gist:


    // Mounting brackets for eShine under-counter LED lights
    // Ed Nisley KE4ZNU December 2016
    //- Extrusion parameters must match reality!
    ThreadThick = 0.25;
    ThreadWidth = 0.40;
    HoleWindage = 0.2;
    Protrusion = 0.1; // make holes end cleanly
    inch = 25.4;
    function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit);
    //———-
    // Dimensions
    MountHeight = (1 + 3/16) * inch – 5.0; // under-cab space – base thickness
    THREADOD = 0;
    HEADOD = 1;
    LENGTH = 2;
    WoodScrew = [4.0,8.3,41]; // 8×1-5/8 Deck screw
    WoodScrewRecess = 2.0;
    LEDScrew = [2.0,4.5,8.0]; // M2.5×10 SHCS
    LEDScrewOffset = [1.0,8.2,0]; // hole offset from center point
    JoinerLength = 18.1; // joiner between strips
    EndBlock = [11.0,28.5,MountHeight]; // mounting block size for ends
    //———————-
    // Useful routines
    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);
    }
    // End mounting block with proper hole offsets
    module EndMount(Side = "L") {
    LSO = [((Side == "L") ? 1 : -1)*LEDScrewOffset[0],LEDScrewOffset[1],LEDScrewOffset[2]];
    difference() {
    union() {
    cube(EndBlock,center=true);
    translate([0,1.5*WoodScrew[1],0])
    cube(EndBlock,center=true);
    }
    translate(LSO + [0,0,-EndBlock[2]])
    rotate(180/4)
    PolyCyl(LEDScrew[THREADOD],2*EndBlock[2],4);
    translate([0,(EndBlock[1] + 1.5*WoodScrew[1])/2,-EndBlock[2]])
    rotate(180/6)
    PolyCyl(WoodScrew[THREADOD],2*EndBlock[2],6);
    translate([0,(EndBlock[1] + 1.5*WoodScrew[1])/2,(EndBlock[2]/2 – WoodScrewRecess)])
    rotate(180/6)
    PolyCyl(WoodScrew[HEADOD],WoodScrewRecess + Protrusion,6);
    translate([((Side == "L") ? 1 : -1)*EndBlock[0]/2,0,0])
    rotate([90,0,((Side == "L") ? 1 : -1)*90])
    translate([0,0,-2*ThreadThick])
    linear_extrude(height=4*ThreadThick,convexity=3)
    text(Side,font=":style=bold",valign="center",halign="center");
    }
    }
    module MidMount() {
    XOffset = (JoinerLength + EndBlock[0])/2;
    union() {
    translate([XOffset,0,0])
    EndMount("L");
    cube([JoinerLength,EndBlock[1],EndBlock[2]] + [2*Protrusion,0,0],center=true);
    translate([-XOffset,0,0])
    EndMount("R");
    }
    }
    //———-
    // Build them
    translate([0,0,EndBlock[2]/2]) {
    translate([-(JoinerLength + 2*EndBlock[0]),0,0])
    EndMount("L");
    MidMount();
    translate([(JoinerLength + 2*EndBlock[0]),0,0])
    EndMount("R");
    }