The New Hotness

Stainless steel socket head and button head screws add a certain techie charm to the hard drive platter mirroring the Noval tube:

Noval - Black PETG base - magenta phase — Noval – Black PETG base – magenta phase

Black PETG, rather than cyan or natural filament, suppresses the socket’s glow and emphasizes the tube’s internal lighting:

Noval tube on platter - button-head screws — Noval tube on platter – button-head screws

The base puts the USB-to-serial adapter on the floor and stands the Pro Mini against a flat on the far wall:

Noval tube socket and base - interior layout — Noval tube socket and base – interior layout

A notch for the cable seems like a useful ~~addition~~ subtraction to the socket, because that cable tie just doesn’t look right. I used 4 mm threaded inserts, as those button head screws looked better.

The solid model looks like you’d expect:

Vacuum Tube Lights - hard drive platter base - solid model — Vacuum Tube Lights – hard drive platter base – solid model

Those are 3 mm threaded inserts, again to get the right head size screw on the platter.

The height of the base depends on the size of the socket, with the model maintaining a bit of clearance above the USB adapter. The OD depends on the platter OD, with a fixed overhang, and the insert BCD depends on the OD / insert OD / base wall thickness.

Although I’m using an Arduino Pro Mini and a separate USB-to-serial adapter, a (knockoff) Arduino Nano would be better and cheaper, although the SMD parts on the Nano’s bottom surface make it a bit thicker and less suitable for foam-tape mounting.

I drilled the platter using manual CNC:

Hard drive platter - Noval base drilling — Hard drive platter – Noval base drilling

After centering the origin on the platter hole, the hole positions (for a 71 mm BCD) use LinuxCNC’s polar notation:

g0 @[71/2]^45
g0 @[71/2]^[45+90]
g0 @[71/2]^[45+180]
g0 @[71/2]^-45

I used the Joggy Thing for manual drilling after each move; that’s easier than figuring out the appropriate g81 feed & speed.

The 3D printed base still looks a bit chintzy compared with the platter, but it’s coming along.

The OpenSCAD source code as a GitHub Gist:

	// Vacuum Tube LED Lights
	// Ed Nisley KE4ZNU February … September 2016

	Layout = "PlatterBase"; // Cap LampBase USBPort Bushings
	// Socket(s) (Build)FinCap Platter[Base\|Fixture]
	DefaultSocket = "Noval";

	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_TUBEOD = 7; // envelope or base diameter
	T_PIPEOD = 8; // light pipe from LED to tube base (clear evac tip / spigot)
	T_SCREWOC = 9; // mounting screw holes

	// Name pins BCD dia length hole punch tube pipe screw
	TubeData = [
	["Mini7", 8, 9.53, 1.016, 7.0, 16.0, 25.0, 18.0, 5.0, 35.0], // punch 11/16, screw 22.5 OC
	["Octal", 8, 17.45, 2.36, 10.0, 36.2, (8 + 1)/8 * inch, 32.0, 11.5, 47.0], // screw 39.0 OC
	["Noval", 10, 11.89, 1.1016, 7.0, 22.0, 25.0 , 21.0, 7.5, 35.0], // punch 7/8, screw 28.0 OC
	["Magnoval", 10, 17.45, 1.27, 9.0, 29.7, (4 + 1)/4 * inch, 46.0, 12.4, 38.2], // similar to Novar
	["Duodecar", 13, 19.10, 1.05, 9.0, 32.0, (4 + 1)/4 * inch, 38.0, 12.5, 47.0], // screw 39.0 OC
	];

	ID = 0;
	OD = 1;
	LENGTH = 2;

	Pixel = [7.0,10.0,3.0]; // ID = contact patch, OD = PCB dia, LENGTH = overall thickness

	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] + 2FinCutterOD),30.0,(10.0 + 2Pixel[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


	//———————-
	// 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*Pixel[LENGTH])];

	CapSides = 8*4;

	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=(CapSize[OD] + 23ThreadWidth),d2=CapSize[OD],h=1.5*Pixel[LENGTH],$fn=CapSides); // skirt
	}

	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],(1.5*Pixel[LENGTH] + Protrusion),CapSides);

	translate([0,0,(1.5*Pixel[LENGTH] – 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,(CapSize[LENGTH] – CapTube[OD]/(2*cos(180/8)))]) // 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(PIFinCapSize[ID] / (2FinCutterOD));
	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],(1.5*Pixel[LENGTH] + Protrusion),FinSides);

	PolyCyl(Pixel[ID],(FinCapSize[LENGTH] – 3*ThreadThick),FinSides); // bore for LED wiring

	translate([0,0,(FinCapSize[LENGTH] – 3ThreadThick – 2CableOD/(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 = [4.0inch,4.5inch,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
	[3.9,5.0,8.0] // 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[ID] – Stud[OD] + (Stud[OD] – Stud[ID])/2);
	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])
	rotate(180/StudSides)
	difference() {
	cylinder(d=Stud[OD],h=Stud[LENGTH],$fn=2*StudSides);
	translate([0,0,Bottom])
	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();
	}
	}
	}


	//———————-
	// Drilling fixture for disk platters

	module PlatterFixture() {

	StudOC = [1.16inch,1.16inch]; // Sherline tooling plate screw spacing
	StudClear = 5.0;

	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([i100/2,j100/2,BasePlate[2] – 2*ThreadThick])
	cylinder(d=1.5,h=1,$fn=6);

	for (i=[-1,1], j=[-1,0,1]) // holes for tooling plate studs
	translate([iStudOC[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
	linear_extrude(height=(Platter[LENGTH] + Protrusion),convexity=2)
	difference() {
	circle(d=(Platter[OD] + 1),$fn=8*4);
	circle(d=Platter[ID],$fn=8*4);
	}

	translate([0,0,BasePlate[2] – 4.0]) // drilling recess
	linear_extrude(height=(4.0 + Protrusion),convexity=2)
	difference() {
	circle(d=(Platter[OD] – 10),$fn=8*4);
	circle(d=(Platter[ID] + 10),$fn=8*4);
	}
	}

	}

	//———————-
	// 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]);
	}
	}

	// 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([2ThreadWidth,0.9SocketNut[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([2ThreadWidth,0.9Pixel[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);
	}
	}

	//———————-
	// Build it

	if (Layout == "Cap") {
	if (Section)
	difference() {
	Cap();
	translate([-CapSize[OD],0,CapSize[LENGTH]])
	cube([2CapSize[OD],2CapSize[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([2FinCapSize[OD],2FinCapSize[OD],3*FinCapSize[LENGTH]],center=true);
	translate([-FinCapSize[OD],0,FinCapSize[LENGTH]])
	cube([2FinCapSize[OD],2FinCapSize[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 == "PlatterFixture")
	PlatterFixture();

	if (Layout == "USBPort")
	USBPort();

	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");}

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The New Hotness

Vacuum Tube LEDs: Hard Drive Platter Base