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.

Author: Ed

  • Too Many Deer, Twice More

    We spotted a classic example of deer damage at the corner gas / repair station:

    Deer-smashed car
    Deer-smashed car

    The undamaged bumper below the smashed grill and hood is diagnostic; the legs bounce off the bumper, while the body punches the grill back through the radiator. The airbags didn’t fire, but I’m pretty sure that car is just as dead as the deer.

    Plenty of deer-colored fur clinches the diagnosis:

    Deer-smashed car - hair detail
    Deer-smashed car – hair detail

    A few days later, a vulture overflew me on Hooker Avenue:

    Vulture - 2016-09-25 - Hooker Ave
    Vulture – 2016-09-25 – Hooker Ave

    It was flapping strongly, powering its way up to cruising altitude, which seemed odd that far into the urban heat island. On the return leg of the ride, I saw what had its attention:

    Deer carcass - 2016-09-25 - Hooker Ave
    Deer carcass – 2016-09-25 – Hooker Ave

    All swoll up, as the saying goes, and ready for the carcass disposal crew…

  • More Cheap eBay Hardware Failures

    Data points…

    Another knockoff Neopixel failed in the usual way, after a few days of operation: the first W2812B chip in the string gave off intermittent and random flashes of pure primary colors, the second was dead in the water. Replacing the first chip with Yet Another Knockoff from the same lot restored the tube to good health.

    Some oscilloscope probing revealed a pooched serial data output with no active pullup, so the output data rarely exceeded VCC/2 and generally wouldn’t be accepted by the downstream W2812B. Nothing to show for it, as I couldn’t be bothered to upload a scope shot. Maybe next time.

    One of the counterfeit FTDI USB-to-serial adapters in another tube base failed after a few weeks of operation, with symptoms ranging from hangs while downloading the Arduino program to readback verify mismatches. Replacing the failed adapter and the knockoff Arduino Pro Mini with a knockoff Arduino Nano (using a CH340 USB interface, presumably not a counterfeit) from a recently arrived envelope restored that tube to good health.

    All in all, those knockoff Neopixels have been a constant source of amusement; worth every penny just for the privilege of holding them up for ridicule. The “genuine” FTDI chips weren’t much of a surprise, but I am mildly surprised they work so poorly.

  • Vacuum Tube LEDs: Improved Sockets

    All the sockets now sport channels in the bottom to capture the braid to the plate cap (whether or not the tube has a plate cap) and the wiring from the Arduino:

    Vacuum Tube Lights - Octal Socket - solid model
    Vacuum Tube Lights – Octal Socket – solid model

    The Slic3r preview shows the detail a bit better:

    Vaccum Tube Lights - Octal Socket - Slic3r preview
    Vaccum Tube Lights – Octal Socket – Slic3r preview

    The boss around the pins is now 25 mm OD and snaps neatly into the unpunched hub hole of a hard drive platter:

    0D3 Octal - 25 mm socket OD in platter
    0D3 Octal – 25 mm socket OD in platter

    I moved the mounting holes to 42 mm OC to give the button heads on those screws a bit more clearance from the base.

    Moving the knockoff Neopixel up to the top of the pipe leading to the tube base dramatically increases the amount of light going into the tube envelope:

    0D3 Octal - 25 mm socket - raised LED
    0D3 Octal – 25 mm socket – raised LED

    You can just barely see a strip of foam tape holding the LED PCB (loosely) into the too-large hole.

    The OpenSCAD source code also produces the improved base clamp; to get a socket, just set Layout = "Socket" and away you go. It doesn’t yet have the reduced-diameter hole down the middle; that’s in the nature of fine tuning.

  • Vacuum Tube LEDs: Milling a 0D3 Spigot the Right Way

    Now, with the 0D3 tube properly clamped and aligned in the Sherline mill:

    OD3 Octal - V-block clamp
    OD3 Octal – V-block clamp

    I can slowly run an end mill down onto the spigot:

    0D3 Octal - milling spigot
    0D3 Octal – milling spigot

    Eventually converting the whole post into black dust in the vacuum cleaner:

    0D3 Octal - milled spigot
    0D3 Octal – milled spigot

    That was completely uneventful, which is pretty much the whole point of good fixturing, isn’t it?

    Applying the vacuum cleaner while milling seems to have kept the dust out of the base, although I’m not sure I can pull that trick off every time.

  • Improved Octal Tube Base Clamp

    In order to clamp the tube in a V-block, the clamp must position the tube’s centerline so the envelope will clear the V groove, thusly:

    OD3 Octal - V-block clamp
    OD3 Octal – V-block clamp

    The clamp now extends into the V-block and surrounds the entire Bakelite tube base:

    Octal base compression clamp - Slic3r preview
    Octal base compression clamp – Slic3r preview

    The little divot captures the clamp screw and the slot lets the whole affair compress just enough to firmly squeeze the entire tube base.

    The tube data table now includes columns for the envelope OD and the base OD, although only the 0D3 (and similar) Octal tubes in my collection have a bulging envelope and a smaller base. You can build clamps for cylindrical glass tubes if you like; I don’t vouch for the accuracy of the table contents.

    For whatever it’s worth, the 6SN7GTB tube I started with has a 32 mm Bakelite base and the 0D3 tube has a 29 mm base. That should probably justify two separate entries in the table, but I’m making this up as I go along.

    The OpenSCAD source code as a GitHub Gist:

    // Vacuum Tube LED Lights
    // Ed Nisley KE4ZNU February … September 2016
    Layout = "TubeClamp"; // Cap LampBase USBPort Bushings
    // Socket(s) Cap (Build)FinCap Platter[Base|Fixture]
    // TubeClamp PlatterParts
    DefaultSocket = "Octal";
    Section = false; // cross-section the object
    Support = true;
    //- 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
    // https://en.wikipedia.org/wiki/Tube_socket#Summary_of_Base_Details
    // punch & screw OC modified for drive platter chassis plate
    // platter = 25 mm ID
    // CD = 15 mm ID with raised ring at 37 mm, needs screw head clearance
    T_NAME = 0; // common name
    T_NUMPINS = 1; // total, with no allowance for keying
    T_PINBCD = 2; // tube pin circle diameter
    T_PINOD = 3; // … diameter
    T_PINLEN = 4; // … length (must also clear evacuation tip / spigot)
    T_HOLEOD = 5; // nominal panel hole from various sources
    T_PUNCHOD = 6; // panel hole optimized for inch-size Greenlee punches
    T_BASEOD = 7; // base OD
    T_BULBOD = 8; // glass envelope OD
    T_PIPEOD = 9; // light pipe from LED to tube base (clear evac tip / spigot)
    T_SCREWOC = 10; // mounting screw holes
    T_PLATECAP = 11; // nonzero to print a plate cap
    // Name pins BCD dia length hole punch base bulb pipe screw cap
    TubeData = [
    ["Mini7", 8, 9.53, 1.016, 7.0, 16.0, 25.0, 18.0, 18.0, 5.0, 35.0, 0], // punch 11/16, screw 22.5 OC
    // ["Octal", 8, 17.45, 2.36, 11.0, 36.2, (8 + 1)/8 * inch, 32.0, 38.1, 11.5, 47.0, 1], // screw 39.0 OC, base 32 or 39
    ["Octal", 8, 17.45, 2.36, 11.0, 36.2, 25.0, 29.0, 38.1, 11.5, 42.0, 1], // platter + 4 mm screws
    ["Noval", 10, 11.89, 1.1016, 7.0, 22.0, 25.0, 21.0, 21.0, 7.5, 35.0, 0], // punch 7/8, screw 28.0 OC
    ["Magnoval", 10, 17.45, 1.27, 9.0, 29.7, (4 + 1)/4 * inch, 46.0, 46.0, 12.4, 38.2, 0], // similar to Novar
    // ["Duodecar", 13, 19.10, 1.05, 9.0, 32.0, (4 + 1)/4 * inch, 38.0, 38.0, 12.5, 47.0, 1], // screw was 39.0 OC
    ["Duodecar", 13, 19.10, 1.05, 9.0, 25.0, 25.0, 38.0, 38.0, 12.5, 42.0, 1], // fit un-punched drive platter
    ];
    ID = 0;
    OD = 1;
    LENGTH = 2;
    Pixel = [7.0,10.0,3.0]; // ID = contact patch, OD = PCB dia, LENGTH = overall thickness
    PixelRecessHeight = 1.55*Pixel[LENGTH]; // enough of a recess to allow for tube top curvature
    SocketNut = // socket mounting: threaded insert or nut recess
    // [3.5,5.2,7.2] // 6-32 insert
    [4.0,6.0,5.9] // 4 mm short insert
    ;
    NutSides = 8;
    SocketShim = 2*ThreadThick; // between pin holes and pixel top
    SocketFlange = 1.5; // rim around socket below punchout
    PanelThick = 1.5; // socket extension through punchout
    FinCutterOD = 1/8 * inch;
    FinCapSize = [(Pixel[OD] + 2*FinCutterOD),30.0,(10.0 + 2*Pixel[LENGTH])];
    USBPCB =
    // [28,16,6.5] // small Sparkfun knockoff
    [36,18 + 1,5.8 + 0.4] // Deek-Robot fake FTDI with ISP header
    ;
    Platter = [25.0,95.0,1.26]; // hard drive platter dimensions
    PlatterSides = 8*4; // polygon approximation
    //———————-
    // 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,$fn=Sides);
    }
    //———————-
    // Tube cap
    CapTube = [4.0,3/16 * inch,10.0]; // brass tube for flying lead to cap LED
    CapSize = [Pixel[ID],(Pixel[OD] + 2.0),(CapTube[OD] + 2.0*Pixel[LENGTH])];
    CapSides = 8*4;
    SkirtOD = CapSize[OD] + 4*ThreadWidth;
    CapTubeHeight = (CapSize[LENGTH] + PixelRecessHeight)/2;
    CapTubeBossOD = 1*ThreadWidth + 2*(CapTubeHeight – PixelRecessHeight)/cos(180/8);
    module Cap() {
    difference() {
    union() {
    cylinder(d=CapSize[OD],h=(CapSize[LENGTH]),$fn=CapSides); // main cap body
    translate([0,0,CapSize[LENGTH]]) // rounded top
    scale([1.0,1.0,0.65])
    sphere(d=CapSize[OD]/cos(180/CapSides),$fn=CapSides); // cos() fixes slight undersize vs cylinder
    cylinder(d1=SkirtOD,d2=CapSize[OD],h=PixelRecessHeight,$fn=CapSides); // skirt
    translate([0,-SkirtOD/2,CapTubeHeight]) // boss around brass tube
    rotate([-90,0,0])
    rotate(180/8)
    cylinder(d=CapTubeBossOD,h=CapTube[LENGTH],$fn=8);
    }
    translate([0,0,-Protrusion]) // bore for wiring to LED
    PolyCyl(CapSize[ID],(CapSize[LENGTH] + 3*ThreadThick + Protrusion),CapSides);
    translate([0,0,-Protrusion]) // PCB recess with clearance for tube dome
    PolyCyl(Pixel[OD],(PixelRecessHeight + Protrusion),CapSides);
    translate([0,0,(PixelRecessHeight – Protrusion)]) // small step + cone to retain PCB
    cylinder(d1=(Pixel[OD]/cos(180/CapSides) + HoleWindage),d2=Pixel[ID],h=(Pixel[LENGTH] + Protrusion),$fn=CapSides);
    translate([0,0,CapTubeHeight]) // hole for brass tube holding wire loom
    rotate([90,0,0]) rotate(180/8)
    PolyCyl(CapTube[OD],CapSize[OD],8);
    }
    }
    //———————-
    // Heatsink tube cap
    module FinCap() {
    CableOD = 3.5; // cable + braid diameter
    BulbOD = 3.75 * inch; // bulb OD; use 10 inches for flat
    echo(str("Fin Cutter: ",FinCutterOD));
    FinSides = 2*4;
    BulbRadius = BulbOD / 2;
    BulbDepth = BulbRadius – sqrt(pow(BulbRadius,2) – pow(FinCapSize[OD],2)/4);
    echo(str("Bulb OD: ",BulbOD," recess: ",BulbDepth));
    NumFins = floor(PI*FinCapSize[ID] / (2*FinCutterOD));
    FinAngle = 360 / NumFins;
    echo(str("NumFins: ",NumFins," angle: ",FinAngle," deg"));
    difference() {
    union() {
    cylinder(d=FinCapSize[ID],h=FinCapSize[LENGTH],$fn=2*NumFins); // main body
    for (i = [0:NumFins – 1]) // fins
    rotate(i * FinAngle)
    hull() {
    translate([FinCapSize[ID]/2,0,0])
    rotate(180/FinSides)
    cylinder(d=FinCutterOD,h=FinCapSize[LENGTH],$fn=FinSides);
    translate([(FinCapSize[OD] – FinCutterOD)/2,0,0])
    rotate(180/FinSides)
    cylinder(d=FinCutterOD,h=FinCapSize[LENGTH],$fn=FinSides);
    }
    rotate(FinAngle/2) // cable entry boss
    translate([FinCapSize[ID]/2,0,FinCapSize[LENGTH]/2])
    cube([FinCapSize[OD]/4,FinCapSize[OD]/4,FinCapSize[LENGTH]],center=true);
    }
    for (i = [1:NumFins – 1]) // fin inner gullets, omit cable entry side
    rotate(i * FinAngle + FinAngle/2) // joint isn't quite perfect, but OK
    translate([FinCapSize[ID]/2,0,-Protrusion])
    rotate(0*180/FinSides)
    cylinder(d=FinCutterOD/cos(180/FinSides),h=(FinCapSize[LENGTH] + 2*Protrusion),$fn=FinSides);
    translate([0,0,-Protrusion]) // PCB recess
    PolyCyl(Pixel[OD],(PixelRecessHeight + Protrusion),FinSides);
    PolyCyl(Pixel[ID],(FinCapSize[LENGTH] – 3*ThreadThick),FinSides); // bore for LED wiring
    translate([0,0,(FinCapSize[LENGTH] – 3*ThreadThick – 2*CableOD/(2*cos(180/8)))]) // cable inlet
    rotate(FinAngle/2) rotate([0,90,0]) rotate(180/8)
    PolyCyl(CableOD,FinCapSize[OD],8);
    if (BulbOD <= 10.0 * inch) // curve for top of bulb
    translate([0,0,-(BulbRadius – BulbDepth + 2*ThreadThick)]) // … slightly flatten tips
    sphere(d=BulbOD,$fn=16*FinSides);
    }
    }
    //———————-
    // Aperture for USB-to-serial adapter snout
    // These are all magic numbers, of course
    module USBPort() {
    translate([0,USBPCB[0]])
    rotate([90,0,0])
    linear_extrude(height=USBPCB[0])
    polygon(points=[
    [0,0],
    [USBPCB[1]/2,0],
    [USBPCB[1]/2,0.5*USBPCB[2]],
    [USBPCB[1]/3,USBPCB[2]],
    [-USBPCB[1]/3,USBPCB[2]],
    [-USBPCB[1]/2,0.5*USBPCB[2]],
    [-USBPCB[1]/2,0],
    ]);
    }
    //———————-
    // Box for Leviton ceramic lamp base
    module LampBase() {
    Insert = [3.5,5.2,7.2]; // 6-32 brass insert to match standard electrical screws
    Bottom = 3.0;
    Base = [4.0*inch,4.5*inch,20.0 + Bottom];
    Sides = 12*4;
    Retainer = [3.5,11.0,1.0]; // flat fiber washer holding lamp base screws in place
    StudSides = 8;
    StudOC = 3.5 * inch;
    Stud = [Insert[OD], // insert for socket screws
    min(15.0,1.5*(Base[ID] – StudOC)/cos(180/StudSides)), // OD = big enough to merge with walls
    (Base[LENGTH] – Retainer[LENGTH])]; // leave room for retainer
    union() {
    difference() {
    rotate(180/Sides)
    cylinder(d=Base[OD],h=Base[LENGTH],$fn=Sides);
    rotate(180/Sides)
    translate([0,0,Bottom])
    cylinder(d=Base[ID],h=Base[LENGTH],$fn=Sides);
    translate([0,-Base[OD]/2,Bottom + 1.2]) // mount on double-sided foam tape
    rotate(0)
    USBPort();
    }
    for (i = [-1,1])
    translate([i*StudOC/2,0,0])
    rotate(180/StudSides)
    difference() {
    cylinder(d=Stud[OD],h=Stud[LENGTH],$fn=StudSides);
    translate([0,0,Bottom])
    PolyCyl(Stud[ID],(Stud[LENGTH] – (Bottom – Protrusion)),6);
    }
    }
    }
    //———————-
    // Base for hard drive platters
    module PlatterBase(TubeName = DefaultSocket) {
    PCB =
    [36,18,3] // Arduino Pro Mini
    ;
    Tube = search([TubeName],TubeData,1,0)[0];
    SocketHeight = Pixel[LENGTH] + SocketShim + TubeData[Tube][T_PINLEN] – PanelThick;
    echo(str("Base for ",TubeData[Tube][0]," socket"));
    Overhang = 5.5; // platter overhangs base by this much
    Bottom = 4*ThreadThick;
    Base = [(Platter[OD] – 3*Overhang), // smaller than 3.5 inch Sch 40 PVC pipe…
    (Platter[OD] – 2*Overhang),
    2.0 + max(PCB[1],(2.0 + SocketHeight + USBPCB[2])) + Bottom];
    Sides = 24*4;
    echo(str(" Height: ",Base[2]," mm"));
    Insert = // platter mounting: threaded insert or nut recess
    // [3.5,5.2,7.2] // 6-32 insert
    [3.7,5.0,8.0] // 3 mm – long insert
    ;
    NumStuds = 4;
    StudSides = 8;
    Stud = [Insert[OD], // insert for socket screws
    2*Insert[OD], // OD = big enough to merge with walls
    Base[LENGTH]]; // leave room for retainer
    StudBCD = floor(Base[OD] – Stud[OD]/cos(180/StudSides));
    echo(str("Platter screw BCD: ",StudBCD," mm"));
    PCBInset = Base[ID]/2 – sqrt(pow(Base[ID]/2,2) – pow(PCB[0],2)/4);
    union() {
    difference() {
    rotate(180/Sides)
    cylinder(d=Base[OD],h=Base[LENGTH],$fn=Sides);
    rotate(180/Sides)
    translate([0,0,Bottom])
    cylinder(d=Base[ID],h=Base[LENGTH],$fn=Sides);
    translate([0,-Base[OD]/2,Bottom + 1.2]) // mount PCB on foam tape
    rotate(0)
    USBPort();
    }
    for (a = [0:(NumStuds – 1)]) // platter mounting studs
    rotate(180/NumStuds + a*360/(NumStuds))
    translate([StudBCD/2,0,0])
    difference() {
    rotate(180/(2*StudSides))
    cylinder(d=Stud[OD],h=Stud[LENGTH],$fn=2*StudSides);
    translate([0,0,Bottom])
    rotate(180/StudSides)
    PolyCyl(Stud[ID],(Stud[LENGTH] – (Bottom – Protrusion)),StudSides);
    }
    intersection() { // microcontroller PCB mounting plate
    rotate(180/Sides)
    cylinder(d=Base[OD],h=Base[LENGTH],$fn=Sides);
    translate([-PCB[0]/2,(Base[ID]/2 – PCBInset),0])
    cube([PCB[0],Base[OD]/2,Base[LENGTH]],center=false);
    }
    difference() {
    intersection() { // totally ad-hoc bridge around USB opening
    rotate(180/Sides)
    cylinder(d=Base[OD],h=Base[LENGTH],$fn=Sides);
    translate([-1.25*USBPCB[1]/2,-(Base[ID]/2),0])
    cube([1.25*USBPCB[1],2.0,Base[LENGTH]],center=false);
    }
    translate([0,-Base[OD]/2,Bottom + 1.2]) // mount PCB on foam tape
    rotate(0)
    USBPort();
    translate([0,-(Base[ID]/2 – 2.0 + 1*ThreadWidth),Bottom – 3*ThreadThick]) // legend
    rotate([90,0,180])
    linear_extrude(height=1*ThreadWidth + Protrusion) {
    translate([0,(Base[LENGTH] – 5.5),0])
    text(text=TubeName,size=4,font="Arial:style=Bold",halign="center");
    // translate([0,(Base[LENGTH] – 8.5),0])
    // text(text=str("BCD ",StudBCD),size=2,font="Arial",halign="center");
    translate([0,(Base[LENGTH] – 11),0])
    text(text="KE4ZNU",size=3,font="Arial",halign="center");
    }
    }
    }
    }
    //———————-
    // Drilling fixture for disk platters
    module PlatterFixture() {
    StudOC = [1.16*inch,1.16*inch]; // Sherline tooling plate screw spacing
    StudClear = 5.0;
    AlignOffset = 100;
    AlignBar = [3*ThreadWidth,10.0,3*ThreadThick];
    BasePlate = [(20 + StudOC[0]*ceil(Platter[OD] / StudOC[0])),(Platter[OD] + 10),7.0];
    PlateRound = 10.0; // corner radius
    difference() {
    hull() // basic block
    for (i=[-1,1], j=[-1,1])
    translate([i*(BasePlate[0]/2 – PlateRound),j*(BasePlate[1]/2 – PlateRound),0])
    cylinder(r=PlateRound,h=BasePlate[2],$fn=4*4);
    for (i=[-1,1], j=[-1,1]) // index marks
    translate([i*AlignOffset/2,j*AlignOffset/2,BasePlate[2] – 2*ThreadThick])
    cylinder(d=1.5,h=1,$fn=6);
    for (i=[-1,1])
    translate([i*(AlignOffset + AlignBar[0])/2,0,(BasePlate[2] – AlignBar[2]/2 + Protrusion/2)])
    cube(AlignBar + [0,0,Protrusion],center=true);
    for (j=[-1,1])
    translate([0,j*(AlignOffset + AlignBar[0])/2,(BasePlate[2] – AlignBar[2]/2 + Protrusion/2)])
    rotate(90)
    cube(AlignBar + [0,0,Protrusion],center=true);
    for (a=[0:90:270])
    rotate(a)
    translate([(AlignBar[1]/2 + AlignBar[0]/2),0,(BasePlate[2] – AlignBar[2]/2 + Protrusion/2)])
    cube(AlignBar + [0,-Protrusion,Protrusion],center=true);
    for (i=[-1,1], j=[-1,0,1]) // holes for tooling plate studs
    translate([i*StudOC[0]*ceil(Platter[OD] / StudOC[0])/2,j*StudOC[0],-Protrusion])
    PolyCyl(StudClear,BasePlate[2] + 2*Protrusion,6);
    translate([0,0,-Protrusion]) // center clamp hole
    PolyCyl(StudClear,BasePlate[2] + 2*Protrusion,6);
    translate([0,0,BasePlate[2] – Platter[LENGTH]]) // disk locating recess
    rotate(180/PlatterSides)
    linear_extrude(height=(Platter[LENGTH] + Protrusion),convexity=2)
    difference() {
    circle(d=(Platter[OD] + 1),$fn=PlatterSides);
    circle(d=Platter[ID],$fn=PlatterSides);
    }
    translate([0,0,BasePlate[2] – 4.0]) // drilling recess
    rotate(180/PlatterSides)
    linear_extrude(height=(4.0 + Protrusion),convexity=2)
    difference() {
    circle(d=(Platter[OD] – 10),$fn=PlatterSides);
    circle(d=(Platter[ID] + 10),$fn=PlatterSides);
    }
    }
    }
    //———————-
    // Tube Socket
    module Socket(Name = DefaultSocket) {
    NumSides = 6*4;
    Tube = search([Name],TubeData,1,0)[0];
    echo(str("Building ",TubeData[Tube][0]," socket"));
    echo(str(" Punch: ",TubeData[Tube][T_PUNCHOD]," mm = ",TubeData[Tube][T_PUNCHOD]/inch," inch"));
    echo(str(" Screws: ",TubeData[Tube][T_SCREWOC]," mm =",TubeData[Tube][T_SCREWOC]/inch," inch OC"));
    OAH = Pixel[LENGTH] + SocketShim + TubeData[Tube][T_PINLEN];
    BaseHeight = OAH – PanelThick;
    difference() {
    union() {
    linear_extrude(height=BaseHeight) // base outline
    hull() {
    circle(d=(TubeData[Tube][T_PUNCHOD] + 2*SocketFlange),$fn=NumSides);
    for (i=[-1,1])
    translate([i*TubeData[Tube][T_SCREWOC]/2,0])
    circle(d=2.0*SocketNut[OD],$fn=NumSides);
    }
    cylinder(d=TubeData[Tube][T_PUNCHOD],h=OAH,$fn=NumSides); // boss in chassis punch hole
    }
    for (i=[0:(TubeData[Tube][T_NUMPINS] – 1)]) // tube pins
    rotate(i*360/TubeData[Tube][T_NUMPINS])
    translate([TubeData[Tube][T_PINBCD]/2,0,(OAH – TubeData[Tube][T_PINLEN])])
    rotate(180/4)
    PolyCyl(TubeData[Tube][T_PINOD],(TubeData[Tube][T_PINLEN] + Protrusion),4);
    for (i=[-1,1]) // mounting screw holes & nut traps / threaded inserts
    translate([i*TubeData[Tube][T_SCREWOC]/2,0,-Protrusion]) {
    PolyCyl(SocketNut[OD],(SocketNut[LENGTH] + Protrusion),NutSides);
    PolyCyl(SocketNut[ID],(OAH + 2*Protrusion),NutSides);
    }
    translate([0,0,-Protrusion]) { // LED recess
    PolyCyl(Pixel[OD],(Pixel[LENGTH] + Protrusion),8);
    }
    translate([0,0,(Pixel[LENGTH] – Protrusion)]) { // light pipe
    rotate(180/TubeData[Tube][T_NUMPINS])
    PolyCyl(TubeData[Tube][T_PIPEOD],(OAH + 2*Protrusion),TubeData[Tube][T_NUMPINS]);
    }
    for (i=[-1,1]) // cable retaining slots
    translate([i*(Pixel[OD] + TubeData[Tube][T_SCREWOC])/4,0,(Pixel[LENGTH] – Protrusion)/2])
    cube([Pixel[LENGTH],TubeData[Tube][T_SCREWOC],(Pixel[LENGTH] + Protrusion)],center=true);
    }
    // Totally ad-hoc support structures …
    if (Support) {
    color("Yellow") {
    for (i=[-1,1]) // nut traps
    translate([i*TubeData[Tube][T_SCREWOC]/2,0,(SocketNut[LENGTH] – ThreadThick)/2])
    for (a=[0:5])
    rotate(a*30 + 15)
    cube([2*ThreadWidth,0.9*SocketNut[OD],(SocketNut[LENGTH] – ThreadThick)],center=true);
    if (Pixel[OD] > TubeData[Tube][T_PIPEOD]) // support pipe only if needed
    translate([0,0,(Pixel[LENGTH] – ThreadThick)/2])
    for (a=[0:7])
    rotate(a*22.5)
    cube([2*ThreadWidth,0.9*Pixel[OD],(Pixel[LENGTH] – ThreadThick)],center=true);
    }
    }
    }
    //———————-
    // Greenlee punch bushings
    module PunchBushing(Name = DefaultSocket) {
    PunchScrew = 9.5;
    BushingThick = 3.0;
    Tube = search([Name],TubeData,1,0)[0];
    echo(str("Building ",TubeData[Tube][0]," bushing"));
    NumSides = 6*4;
    difference() {
    union() {
    cylinder(d=Platter[ID],h=BushingThick,$fn=NumSides);
    cylinder(d=TubeData[Tube][T_PUNCHOD],h=(BushingThick – Platter[LENGTH]),$fn=NumSides);
    }
    translate([0,0,-Protrusion])
    PolyCyl(PunchScrew,5.0,8);
    }
    }
    //———————-
    // Tube clamp
    module TubeClamp(Name = DefaultSocket) {
    Tube = search([Name],TubeData,1,0)[0];
    echo(str("Building ",TubeData[Tube][0]," clamp"));
    ClampWidth = 37.0; // inside of clamp arch
    ClampLength = 20; // along tube base
    ClampScrew = [6.0,7.8,6.0]; // nose of clamp screw
    ClampBlock = [4*ThreadWidth + TubeData[Tube][T_BULBOD],
    4*ThreadWidth + TubeData[Tube][T_BULBOD],
    ClampLength];
    difference() {
    union() {
    intersection() {
    translate([0,0,ClampBlock[2]/2])
    rotate(45)
    cube(ClampBlock,center=true); // V-block sides
    translate([0,-ClampWidth/2,ClampBlock[2]/2])
    cube([ClampWidth,ClampWidth,ClampBlock[2]],center=true); // clamp sides
    }
    intersection() {
    cylinder(d=ClampWidth,h=ClampBlock[2]);
    translate([0,ClampWidth/4,ClampBlock[2]/2])
    cube([ClampWidth,ClampWidth/2,ClampBlock[2]],center=true); // clamp sides
    }
    }
    translate([0,0,-Protrusion]) // remove tube base (remains centered)
    cylinder(d=TubeData[Tube][T_BASEOD],h=(ClampLength + 2*Protrusion));
    translate([0,(ClampWidth/2 + TubeData[Tube][T_BASEOD]/2)/2,ClampBlock[LENGTH]/3])
    rotate([-90,0,0])
    PolyCyl(ClampScrew[ID],1*ClampScrew[LENGTH],6); // clamp screw recess
    translate([0,-(6*ThreadWidth)/2,-Protrusion])
    cube([ClampWidth,6*ThreadWidth,(ClampLength + 2*Protrusion)]); // clamp relief slot
    }
    }
    //———————-
    // Build it
    if (Layout == "Cap") {
    if (Section)
    difference() {
    Cap();
    translate([-CapSize[OD],0,CapSize[LENGTH]])
    cube([2*CapSize[OD],2*CapSize[OD],3*CapSize[LENGTH]],center=true);
    }
    else
    Cap();
    }
    if (Layout == "FinCap") {
    if (Section) render(convexity=5)
    difference() {
    FinCap();
    // translate([0,-FinCapSize[OD],FinCapSize[LENGTH]])
    // cube([2*FinCapSize[OD],2*FinCapSize[OD],3*FinCapSize[LENGTH]],center=true);
    translate([-FinCapSize[OD],0,FinCapSize[LENGTH]])
    cube([2*FinCapSize[OD],2*FinCapSize[OD],3*FinCapSize[LENGTH]],center=true);
    }
    else
    FinCap();
    }
    if (Layout == "BuildFinCap")
    translate([0,0,FinCapSize[LENGTH]])
    rotate([180,0,0])
    FinCap();
    if (Layout == "LampBase")
    LampBase();
    if (Layout == "PlatterBase")
    PlatterBase();
    if (Layout == "PlatterParts") {
    Tube = search([DefaultSocket],TubeData,1,0)[0];
    echo(str("Parts for ",TubeData[Tube][T_NAME]," assembly"));
    PlatterBase();
    translate([0.25*Platter[OD],-0.6*Platter[OD],0])
    rotate(0)
    Socket();
    if (TubeData[Tube][T_PLATECAP])
    for (i=[-1,1])
    translate([(-0.25*Platter[OD] – i*Pixel[OD]),-0.6*Platter[OD],0])
    rotate(i*90)
    Cap();
    }
    if (Layout == "PlatterFixture")
    PlatterFixture();
    if (Layout == "USBPort")
    USBPort();
    if (Layout == "TubeClamp")
    TubeClamp();
    if (Layout == "Bushings")
    PunchBushing();
    if (Layout == "Socket")
    if (Section) {
    difference() {
    Socket();
    translate([-100/2,0,-Protrusion])
    cube([100,50,50],center=false);
    }
    }
    else
    Socket();
    if (Layout == "Sockets") {
    translate([0,50,0])
    Socket("Mini7");
    translate([0,20,0])
    Socket("Octal");
    translate([0,-15,0])
    Socket("Duodecar");
    translate([0,-50,0])
    Socket("Noval");
    translate([0,-85,0])
    Socket("Magnoval");}
    view raw Vacuum Tube Lights.scad hosted with ❤ by GitHub

  • Vacuum Tube LEDs: Grinding Off a 0D3 Base Spigot

    Rummaging in the Hollow State Electronics box produced the shapely 0D3 regulator tube with an intact spigot / key post in its base:

    0D3 voltage regulator tube in socket
    0D3 voltage regulator tube in socket

    Because the glass envelope (1.5 inch = 38.1 mm OD) extends beyond the base (1.125 inch = 28.6 mm OD), the simple base clamp must let the tube extend over the workbench:

    0D3 Octal tube - V-block clamp
    0D3 Octal tube – V-block clamp

    There’s no way to clamp that mess in the Sherline, so, rather than freehanding the shell drill, I misused a Dremel slitting wheel to grind away the end of the spigot, which normally extends a bit beyond the pins so you can’t possibly insert the tube into the socket the wrong way:

    0D3 Octal tube - ground-off spigot tip
    0D3 Octal tube – ground-off spigot tip

    The missing end exposed the hole in the middle of the post and showed this tube’s evacuation tip didn’t extend into the spigot. Emboldened by that, I continued the mission until the wheel wouldn’t reach any further:

    0D3 Octal tube - Dremel grinding
    0D3 Octal tube – Dremel grinding

    That didn’t work well, but at least I didn’t break anything and nobody will ever see those mauled pin tips.

    Obviously, the only way to do this right is to clamp the tube properly and mill the spigot flush with the socket; it’s time for more 3D printing…

  • Maloney Road Repaving

    The Wappinger DPW laid asphalt along Maloney Rd, from side to side and end to end (well, to the end of their jurisdiction at the Lagrange town boundary). We passed the crew putting down the first layer on the westbound side:

    Maloney Road Paving - 2016-09-14
    Maloney Road Paving – 2016-09-14

    A few days later, they were doing the final layer on that side as we approached the Rail Trail entrance:

    Maloney Road Paving - 2016-09-17
    Maloney Road Paving – 2016-09-17

    Sometimes, good things happen out there on the roads!

    [Update: Vedran points to a Youtube video of paving:

    Paving Operations

    By the looks of it they are from (almost) your neck of the woods (NYCDOT). They have a mighty impressive machine going but if you watch the lower right corner for about 10 seconds you’ll spot them paving right over a manhole cover :) Guess no matter how smart the tech, users will always find a way.

    I’ve seen that done, too, but a guy should immediately dig out the cover (using the paint marks on the curb to find it) and taper the edges. That way, the paving machine produces a smooth surface along the street and the cover isn’t (shouldn’t be!) too deeply recessed.

    Sometimes they just spraypaint a circle over the buried cover and wait until somebody must go into that hole before digging it out. That makes a nice, smooth paving job, but eventually produces a steep-walled pit in the pavement which enlarges and crumbles into gravel.

    They should add a ring to the manhole to bring the cover flush with the new surface, but nobody (except the WDPW above!) does that around here until after the third or fourth paving job. Until then, it’s just like a pothole with a slick metallic bottom …

    /update]