Tag: Improvements

Making the world a better place, one piece at a time

Alpha Geek Clock: Radome Update

There being nothing like a new problem to take one’s mind off all one’s old problems:

C-Max CMMR-60 WWVB receiver - D cell display holder — C-Max CMMR-60 WWVB receiver – D cell display holder

It’s a variation on the camera battery and AA alkaline holders for various blinky LEDs:

Astable Multivibrator - D cell WWVB — Astable Multivibrator – D cell WWVB

The little flag holding the C-Max CMMR-60 receiver PCB gets glued to the copper upright to keep it from swiveling in the breeze.

The conical caps on the ferrite bar antenna are glued to the uprights and the antenna, in the expectation this is a one-off build-only project.

Rather than buy specialized D-cell contacts, I used 18650 lithium cell contacts and conjured the bridge by soldering two together:

D cell bridge contact from 18650 contacts

It sits on the windowsill, blinks quietly in the dark, and flickers invisibly during the daytime.

Those D cells came from the same batch that powered the previous version for the last five years, so they probably won’t last that long, even with a Nov 2024 date code.

C-Max is apparently out of the WWVB biz, but you can get a similar Canaduino AM WWVB receiver.

The far more complex EverSet ES100-MOD WWVB receiver requires a microcontroller with an I²C interface and very careful power management.

The OpenSCAD source code as a GitHub Gist:

	// Astable Multivibrator
	// Holder for Alkaline cells
	// Ed Nisley KE4ZNU August 2020
	// 2020-09 add LED radome
	// 2020-11 add radome trim
	// 2021-11 D cells and WWVB receiver

	/* [Layout options] */

	Layout = "Build"; // [Build,Show,Lid,Spider,AntCap,RecFlag]

	CellName = "AA"; // [AA, D]

	Struts = -1; // [0:None, -1:Dual, 1:Quad]

	WWVB = true;

	/* [Hidden] */

	NumCells = 2; // [2]

	// Extrusion parameters

	/* [Hidden] */

	ThreadThick = 0.25;
	ThreadWidth = 0.40;

	HoleWindage = 0.2;

	function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit);
	function IntegerLessMultiple(Size,Unit) = Unit * floor(Size / Unit);

	Protrusion = 0.1; // make holes end cleanly

	inch = 25.4;

	//- Basic dimensions

	WallThick = IntegerMultiple(3.0,ThreadWidth);
	CornerRadius = WallThick/2;

	FloorThick = IntegerMultiple(3.0,ThreadThick);

	TopThick = IntegerMultiple(2.0,ThreadThick);

	WireOD = 1.5; // battery & LED wiring
	WireOC = 8.0; // hole spacing in lid

	Gap = 5.0;

	// Cylindrical cell sizes
	// https://en.wikipedia.org/wiki/List_of_battery_sizes#Cylindrical_batteries

	CELL_NAME = 0;
	CELL_OD = 1;
	CELL_OAL = 2;

	// FIXME search() needs special-casing to properly find AAA and AAAA
	// Which is why CellName is limited to AA

	CellData = [
	["AAAA",8.3,42.5],
	["AAA",10.5,44.5],
	["AA",14.5,50.5],
	["C",26.2,50],
	["D",34.2,61.5],
	["A23",10.3,28.5],
	["CR123A",17.0,34.5],
	["18650",18.8,65.2], // bare 18650 with button end
	["18650Prot",19.0,70.0], // protected 18650 = 19670 plus a bit
	];

	CellIndex = search([CellName],CellData,1,0)[0];
	echo(str("Cell index: ",CellIndex," = ",CellData[CellIndex][CELL_NAME]));

	//- Contact dimensions

	CONTACT_NAME = 0;
	CONTACT_WIDE = 1;
	CONTACT_HIGH = 2;
	CONTACT_THICK = 3; // plate thickness
	CONTACT_TIP = 4; // tip to rear face
	CONTACT_TAB = 5; // solder tab width

	ContactData = [
	["AA+",12.2,12.2,0.3,1.7,3.5], // pos bump
	["AA-",12.2,12.2,0.3,5.0,3.5], // half-compressed neg spring
	["AA+-",28.2,12.2,0.3,5.0,0], // pos-neg bridge

	["D+",18.5,16.0,0.3,2.8,5.5],
	["D-",18.5,16.0,0.3,6.0,5.5],
	["D+-",50.0,19.0,0.3,7.0,0], // solder +/- tabs together

	["Li+",18.5,16.0,0.3,2.8,5.5],
	["Li-",18.5,16.0,0.3,6.0,5.5],
	];

	function ConDat(name,dim) = ContactData[search([name],ContactData,1,0)[0]][dim];

	ContactRecess = 2*ConDat(str(CellName,"+"),CONTACT_THICK);
	ContactOC = CellData[CellIndex][CELL_OD];

	WireBay = 6.0; // room for wiring to contacts

	//- Wire struts

	StrutDia = 1.6; // AWG 14 = 1.6 mm
	StrutSides = 3*4;

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

	StrutBase = [StrutDia,StrutDia + 25ThreadWidth, // ID = wire, OD = buildable
	FloorThick + CellData[CellIndex][CELL_OD]]; // LENGTH = base is flush with cell top

	//- Holder dimensions

	BatterySize = [CellData[CellIndex][CELL_OAL] + // cell
	ConDat(str(CellName,"+"),CONTACT_TIP) + // pos contact
	ConDat(str(CellName,"-"),CONTACT_TIP) – // neg contact
	2*ContactRecess, // sink into wall
	NumCells*CellData[CellIndex][CELL_OD],
	CellData[CellIndex][CELL_OD]
	];

	echo(str("Battery space: ",BatterySize));

	CaseSize = [3*WallThick + // end walls + wiring partition
	BatterySize.x + // cell
	WireBay, // wiring bay
	2*WallThick + BatterySize.y,
	FloorThick + BatterySize.z
	];
	echo(str("CaseSize: ",CaseSize));

	BatteryOffset = (CaseSize.x – (2*WallThick +
	CellData[CellIndex][CELL_OAL] +
	ConDat(str(CellName,"-"),CONTACT_TIP))
	) /2 ;

	ThumbRadius = 0.75 * CaseSize.z;


	StrutOC = [IntegerLessMultiple(CaseSize.x – 2CornerRadius -2StrutBase[OD],5.0),
	IntegerMultiple(CaseSize.y + StrutBase[OD],5.0)];

	StrutAngle = atan(StrutOC.y/StrutOC.x);

	echo(str("Strut OC: ",StrutOC));

	LidSize = [2*WallThick + WireBay + ConDat(str(CellName,"+"),CONTACT_THICK), CaseSize.y, FloorThick/2];

	LidScrew = [2.0,3.8,7.0]; // M2 pan head screw (LENGTH = threaded)
	LidScrewOC = CaseSize.y/2 – CornerRadius – LidScrew[OD]; // allow space around screw head

	//- Piranha LEDs

	PiranhaBody = [8.0,8.0,8.0]; // Z = heatsink fins + plastic body + lens

	PiranhaPin = 0.0; // trimmed pin length beyond heatsink
	PiranhaPinsOC = [5.0,5.0]; // pin XY distance

	PiranhaRecess = PiranhaBody.z + PiranhaPin/2; // minimum LED recess depth

	BallOD = 40.0; // radome sphere
	BallSides = 434; // nice smoothness

	PillarOD = norm([PiranhaBody.x,PiranhaBody.y]) + 2*WallThick;

	BallChordM = BallOD/2 – sqrt(pow(BallOD/2,2) – (pow(PillarOD,2))/4);
	echo(str("Ball chord depth: ",BallChordM));

	RadomePillar = [norm([PiranhaBody.x,PiranhaBody.y]), // ID = LED diagonal
	PillarOD,
	FloorThick + PiranhaRecess + BallChordM]; // height to top of ball chord
	echo(str("Pillar: ",RadomePillar));

	RadomeBar = [StrutBase[OD]*cos(180/StrutSides),StrutOC.y,StrutBase[OD]/2];

	Tape = [RadomePillar[ID],16.0,1.0]; // sticky tape disk, OD to match hole punch

	//- WWVB receiver hardware

	Antenna = [10.0 + 0.5,14.0,60.0 + 2.0]; // ferrite antenna bar with clearance

	AntCapSize = [Antenna[ID] + 1.0,Antenna[OD],5.0]; // LENGTH=insertion

	RecPCB = [24.0,16.0,5.0];

	//———————-
	// 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(r=(FixDia + HoleWindage)/2,h=Height,$fn=Sides);
	}

	// Spider for single LED atop struts, with the ball

	module DualSpider() {

	difference() {
	union() {
	for (j=[-1,1]) {
	for (k=[-1,1])
	translate([0,jStrutOC.y/2,kRadomeBar.z])
	rotate(180/StrutSides)
	sphere(d=StrutBase[OD]/cos(180/StrutSides),$fn=StrutSides);
	translate([0,j*StrutOC.y/2,0])
	rotate(180/StrutSides)
	cylinder(d=StrutBase[OD],h=2*RadomeBar.z,center=true,$fn=StrutSides);
	}

	cube(RadomeBar,center=true); // connecting bar

	cylinder(d=RadomePillar[OD],h=RadomePillar[LENGTH],$fn=BallSides);

	translate([0,0,-RadomeBar.z/2])
	cylinder(d1=0.9*RadomePillar[OD],d2=RadomePillar[OD],h=RadomeBar.z/2,$fn=BallSides);
	}

	for (j=[-1,1]) // strut wires
	translate([0,jStrutOC.y/2,-3StrutBase[OD]/2])
	rotate(180/StrutSides)
	PolyCyl(StrutBase[ID],2*StrutBase[OD],StrutSides);

	for (k=[-1,1]) // LED wiring through bar
	translate([0,k(StrutOC.x/2 – 2RadomeBar.x),-RadomeBar.z])
	rotate(180/6)
	PolyCyl(StrutBase[ID],2*RadomeBar.z,6);

	translate([0,0,BallOD/2 + RadomePillar[LENGTH] – BallChordM]) // ball inset
	sphere(d=BallOD);

	translate([0,0,BallOD/2 + RadomePillar[LENGTH] – BallChordM – Tape[LENGTH]/2]) // tape inset
	intersection() {
	sphere(d=BallOD);
	cylinder(d=Tape[OD],h=2*BallOD,center=true);
	}

	translate([0,0,RadomePillar.z – PiranhaRecess + RadomePillar.z/2]) // LED inset
	cube(PiranhaBody + [HoleWindage,HoleWindage,RadomePillar.z],center=true); // XY clearance

	translate([0,0,StrutBase[OD]/4 + WireOD/2 + 0*Protrusion]) // wire channels
	cube([WireOD,RadomePillar[OD] + 2*WallThick,WireOD],center=true);

	}
	}

	//– WWVB antenna support cap

	module AntennaBar() {
	rotate([90,0,0])
	union() {
	cylinder(d=Antenna[ID],h=Antenna[LENGTH],$fn=BallSides,center=true);
	cylinder(d=2Antenna[OD],h=Antenna[LENGTH] – 2AntCapSize[LENGTH],$fn=BallSides,center=true);
	}
	}

	module AntennaCap() {
	rotate([90,0,0])
	intersection() {
	translate([0,-Antenna[LENGTH]/2 + AntCapSize[LENGTH],0])
	difference() {
	hull() {
	rotate([90,0,0])
	cylinder(d=AntCapSize[OD],h=Antenna[LENGTH],$fn=BallSides,center=true);
	for (j=[-1,1])
	translate([0,j*StrutOC.y/2,0])
	rotate(180/StrutSides)
	cylinder(d=StrutBase[OD],h=1*StrutBase[OD],$fn=StrutSides,center=true);
	}
	for (j=[-1,1])
	translate([0,j*StrutOC.y/2,-Antenna[OD]/2])
	rotate(180/StrutSides)
	PolyCyl(StrutBase[ID],Antenna[OD],StrutSides);
	AntennaBar();
	}
	rotate([-90,0,0])
	cylinder(d=Antenna[OD],h=Antenna[LENGTH],center=false);
	}
	}


	//– WWVB PCB support flag

	module RecFlag() {

	difference() {
	hull() {
	rotate(180/StrutSides)
	cylinder(d=StrutBase[OD],h=RecPCB.x,$fn=StrutSides);
	translate([0,RecPCB.y,0])
	rotate(180/StrutSides)
	cylinder(d=StrutBase[OD],h=RecPCB.x,$fn=StrutSides);
	}
	translate([0,0,-Protrusion])
	rotate(180/StrutSides)
	PolyCyl(StrutBase[ID],2*RecPCB.x,StrutSides);
	translate([0,StrutBase[OD]/2,-Protrusion])
	cube([StrutBase[OD],RecPCB.y,2*RecPCB.x],center=false);
	}

	}

	//– Overall case with origin at battery center

	module Case() {

	union() {

	difference() {
	union() {
	hull()
	for (i=[-1,1], j=[-1,1])
	translate([i*(CaseSize.x/2 – CornerRadius),
	j*(CaseSize.y/2 – CornerRadius),
	0])
	cylinder(r=CornerRadius/cos(180/8),h=CaseSize.z,$fn=8); // cos() fixes undersize spheres!

	if (Struts)
	for (i = (Struts == 1) ? [-1,1] : -1) { // strut bases
	hull()
	for (j=[-1,1])
	translate([iStrutOC.x/2,jStrutOC.y/2,0])
	rotate(180/StrutSides)
	cylinder(d=StrutBase[OD],h=StrutBase[LENGTH],$fn=StrutSides);

	translate([i*StrutOC.x/2,0,StrutBase[LENGTH]/2])
	cube([2*StrutBase[OD],StrutOC.y,StrutBase[LENGTH]],center=true); // blocks for fairing

	for (j=[-1,1]) // hemisphere caps
	translate([i*StrutOC.x/2,
	j*StrutOC.y/2,
	StrutBase[LENGTH]])
	rotate(180/StrutSides)
	sphere(d=StrutBase[OD]/cos(180/StrutSides),$fn=StrutSides);

	}
	}

	translate([BatteryOffset,0,BatterySize.z/2 + FloorThick]) // cells
	cube(BatterySize + [0,0,Protrusion],center=true);

	translate([BatterySize.x/2 + BatteryOffset + ContactRecess/2 – Protrusion/2, // contacts
	0,
	BatterySize.z/2 + FloorThick])
	cube([ContactRecess + Protrusion,
	ConDat(str(CellName,"+-"),CONTACT_WIDE),
	ConDat(str(CellName,"+-"),CONTACT_HIGH)
	],center=true);

	translate([-(BatterySize.x/2 – BatteryOffset + ContactRecess/2 – Protrusion/2),
	ContactOC/2,
	BatterySize.z/2 + FloorThick])
	cube([ContactRecess + Protrusion,
	ConDat(str(CellName,"+"),CONTACT_WIDE),
	ConDat(str(CellName,"+"),CONTACT_HIGH)
	],center=true);

	translate([-(BatterySize.x/2 – BatteryOffset + ContactRecess/2 – Protrusion/2),
	-ContactOC/2,
	BatterySize.z/2 + FloorThick])
	cube([ContactRecess + Protrusion,
	ConDat(str(CellName,"-"),CONTACT_WIDE),
	ConDat(str(CellName,"-"),CONTACT_HIGH)
	],center=true);

	translate([-CaseSize.x/2 + WireBay/2 + WallThick, // wire bay with screw bosses
	0,
	BatterySize.z/2 + FloorThick + Protrusion/2])
	cube([WireBay,
	2LidScrewOC – LidScrew[ID] – 24*ThreadWidth,
	BatterySize.z + Protrusion
	],center=true);

	for (j=[-1,1]) // screw holes
	translate([-CaseSize.x/2 + WireBay/2 + WallThick,
	j*LidScrewOC,
	CaseSize.z – LidScrew[LENGTH] + Protrusion])
	PolyCyl(LidScrew[ID],LidScrew[LENGTH],6);


	for (j=[-1,1])
	translate([-(BatterySize.x/2 – BatteryOffset + WallThick/2), // contact tabs
	j*ContactOC/2,
	BatterySize.z + FloorThick – Protrusion])
	cube([2*WallThick,
	ConDat(str(CellName,"+"),CONTACT_TAB),
	(BatterySize.z – ConDat(str(CellName,"+"),CONTACT_HIGH))
	],center=true);

	if (false)
	translate([0,0,CaseSize.z]) // finger cutout
	rotate([90,00,0])
	cylinder(r=ThumbRadius,h=2*CaseSize.y,center=true,$fn=22);

	if (Struts)
	for (i2 = (Struts == 1) ? [-1,1] : -1) { // strut wire holes and fairing
	for (j=[-1,1])
	translate([i2StrutOC.x/2,jStrutOC.y/2,FloorThick])
	rotate(180/StrutSides)
	PolyCyl(StrutBase[ID],2*StrutBase[LENGTH],StrutSides);

	for (i=[-1,1], j=[-1,1]) // fairing cutaways
	translate([iStrutBase[OD] + (i2StrutOC.x/2),
	j*StrutOC.y/2,
	-Protrusion])
	rotate(180/StrutSides)
	PolyCyl(StrutBase[OD],StrutBase[LENGTH] + 2*Protrusion,StrutSides);
	}

	translate([0,0,ThreadThick – Protrusion]) // recess around name
	cube([51.0,15,2*ThreadThick],center=true);

	}

	linear_extrude(height=2*ThreadThick + Protrusion,convexity=10) {
	translate([0,-3.5,0])
	mirror([0,1,0])
	text(text="softsolder",size=6,spacing=1.20,font="Arial:style:Bold",halign="center",valign="center");
	translate([0,3.5,0])
	mirror([0,1,0])
	text(text=".com",size=6,spacing=1.20,font="Arial:style:Bold",halign="center",valign="center");
	}
	}
	}


	module Lid() {

	difference() {
	hull()
	for (i=[-1,1], j=[-1,1], k=[-1,1])
	translate([i*(LidSize.x/2 – CornerRadius),
	j*(LidSize.y/2 – CornerRadius),
	k*(LidSize.z – CornerRadius)]) // double thickness for flat bottom
	sphere(r=CornerRadius/cos(180/8),$fn=8);

	translate([0,0,-LidSize.z]) // remove bottom
	cube([(LidSize.x + 2Protrusion),(LidSize.y + 2Protrusion),2*LidSize.z],center=true);

	for (j=[-1,1]) // wire holes
	translate([0,j*WireOC/2,-Protrusion])
	PolyCyl(WireOD,2*LidSize.z,6);

	for (j=[-1,1])
	translate([0,j*LidScrewOC,-Protrusion])
	PolyCyl(LidScrew[ID],2*LidSize.z,6);

	}
	}


	//——————-
	// Show & build stuff

	if (Layout == "Case")
	Case();

	if (Layout == "Lid")
	Lid();

	if (Layout == "AntCap")
	AntennaCap();

	if (Layout == "RecFlag")
	RecFlag();

	if (Layout == "Spider")
	if (Struts == -1)
	DualSpider();
	else
	cube(10,center=true);

	if (Layout == "Build") {
	rotate(90)
	Case();
	translate([0,-(CaseSize.x/2 + LidSize.x/2 + Gap),0])
	rotate(90)
	Lid();
	if (Struts == -1) {
	difference() {
	union() {
	translate([CaseSize.x/2 + RadomePillar[OD],0,0])
	DualSpider();
	translate([-(CaseSize.x/2 + RadomePillar[OD]),0,0])
	rotate([180,0,0])
	DualSpider();
	}
	translate([0,0,-2*CaseSize.z])
	rotate(90)
	cube(4*CaseSize,center=true);
	}
	}
	if (WWVB) {
	for (i=[-1,1])
	translate([i*(Antenna[LENGTH]/2 – AntCapSize[LENGTH]),CaseSize.x/2 + Antenna[OD],0])
	AntennaCap();
	translate([0,CaseSize.x/2 + Antenna[OD],0])
	RecFlag();
	}
	}

	if (Layout == "Show") {
	Case();
	for (j=[-1,1])
	color("Brown",0.3)
	translate([-StrutOC.x/2,j*StrutOC.y/2,Protrusion])
	cylinder(d=StrutDia[ID],h=3*CaseSize.z,$fn=StrutSides);
	translate([-(CaseSize.x/2 – LidSize.x/2),0,(CaseSize.z + Gap)])
	Lid();
	if (Struts == -1)
	translate([-StrutOC.x/2,0,3*CaseSize.z])
	DualSpider();
	if (WWVB) {
	for (j=[-1,1])
	translate([-StrutOC.x/2,,j(Antenna[LENGTH]/2 – AntCapSize[LENGTH]),1.5CaseSize.z])
	rotate([-j*90,0,0])
	AntennaCap();
	translate([-StrutOC.x/2,,-(StrutOC.y/2),2*CaseSize.z])
	RecFlag();
	}
	}

view raw Astable Multivibrator – Alkaline Batteries.scad hosted with ❤ by GitHub

2021-11-17

LED-ified Halogen Desk Lamp: DC LED Driver

Feeding half-wave rectified 12 V AC into the 4 W LED lamp I hung on the end of the halogen desk lamp worked at human scale, but produced dark bars across images made with my Pixel phones. Having solved that problem for the LED lighting on Mary’s sewing machines, I replaced the OEM transformer with a 12 VDC power supply:

LED Desk Lamp – Driver installed

The steel lump inside the base is the OEM weight that, in addition to two pounds of transformer, kept the whole affair from toppling over.

The transformer inside the DC supply weighs basically nothing:

LED Desk Lamp – Driver PCB

The original 12 VAC transformer powered a 50 W halogen bulb and loafed along at 14.7 VAC (yes, RMS) into the 4 W LED. The light is somewhat dimmer at 12 VDC, but not enough to worry about.

Aaaaand the photo bars are gone!

2021-11-16
Alpha Geek Clock: Battery Refresh

A pair of D cells can power an obsolete / out of production C-Max CMMR-60 WWVB receiver for about five years and, having the plastic pieces for a blinkie at hand, junking the faded case in favor of a test lashup seemed appropriate:

C-Max CMMR-60 WWVB receiver – AA alkaline test setup

Given the fragility of that ferrite bar, I should conjure a wide D-cell base, a bar holder to cover the ends, and a PCB mount of some sort.

The receiver data pin drives the red LED of an RGB piranha through a 2.2 kΩ SMD resistor, so it’s visible in a dim room. Given that the thing flickers constantly during WWVB’s poor-reception daylight hours, reducing the LED current counts for almost everything.

The antenna has a cap under that heatshrink tubing, which called for a resonance check:

C-Max CMMR-60 WWVB receiver – antenna peaking – driver coil

The blue dingus is an RF sniffer driven three orders of magnitude below its frequency spec:

C-Max CMMR-60 WWVB receiver – antenna peaking – function generator

The antenna response peaks where you’d expect:

C-Max CMMR-60 WWVB receiver – antenna peaking – scope

Given the broad peak and typical tolerances, it’s spot on.

2021-11-15
CNC 3018 Tool Clamp Rehabilitation

The CNC 3018 Z-axis stage has a plastic clamp holding the spindle motor, so I just duplicated the motor diameter in the mounts for my diamond drag bit, cheap pen, and fancy pen holders. For obvious reasons, I tend to err on the small side for anything intended to fit into anything else, which led to each of the holders sporting a small strip of tape to soak up the difference.

While poking around the 3018, I once again noticed the clamp’s crappy fit around the holder:

CNC3018 tool clamp – top

The inside should be circular, but it’s definitely not:

CNC3018 tool clamp – top detail

The end of the 30 mm M3 SHCS bottoms out before the clamp closes, although I’ve managed to crank the screw tight enough to put enough of a dent in there to snug the clamp:

CNC3018 tool clamp – side

Some awkward scraping and filing eroded enough of the plastic to let a 25 mm SHCS close the clamp firmly around the holder:

CNC3018 tool clamp – revised

The tool holders now slide in easily with the screw released and fit firmly with the screw tightened a reasonable amount, minus the tape snippets shimming the difference.

If I had the courage of my convictions, I’d take it all apart, bore the clamp out to a circular profile, realign the clamp screw passage to suit, then rebuild all those tool holders for the new diameter; it now works well enough to tamp that project down.

2021-11-09

Clearing the Noto Font Clutter: Again

Installing Atkinson Hyperlegible reminded me to clear out the Noto font clutter in this (relatively nerecentw) Manjaro installation. Of course fonts now appear in slightly different locations with slightly different names, so this remains just a serving suggestion:

cd /usr/share/fonts/noto
sudo chmod a-w NotoSans-*
sudo chmod a-w NotoSansMono*
sudo chmod a-w NotoSansDisplay*
sudo chmod a-w NotoSansMath*
sudo chmod a-w NotoSansSymbol*
sudo chmod a-w NotoSerif-*
sudo chmod a-w NotoSerifDisplay*
sudo chmod a-w NotoMusic*
sudo chmod a-w NotoMath*
sudo find . -perm /u=w -name \*ttf -delete

Get rid of some other clutter:

cd ../TTF
sudo chmod a-w DejaVu*
sudo chmod a-w Inconsolata-*
sudo find . -perm /u=w -name \*ttf -delete
cd ../droid
sudo chmod a-w DroidSans-Bold.ttf 
sudo chmod a-w DroidSans.ttf 
sudo chmod a-w DroidSansFallback*
sudo chmod a-w DroidSansMono.ttf 
sudo chmod a-w DroidSerif-*
cd ../adobe-source-han-sans
sudo rm *otf

For unknown reasons, we now have two font cache updaters:

sudo fc-cache -v -f
sudo fc-cache-32 -v -f

Now font selection in, say, LibreOffice doesn’t involve paging through a myriad fonts in languages I cannot recognize, let alone read. Admittedly, Inconsolata does have more variations than I’ll ever use.

2021-10-21

Improved Mini-lathe Disk Turning Fixture

Unsurprisingly, the mini-lathe lacks enough stiffness to apply enough force to hold a disk in place while turning its rim:

Tour Easy Rear Running Light – end cap fixture – swirled adhesive

The old South Bend lathe had mojo, but those days are gone.

So drill and tap that fixture for an M3 screw, then stick some coarse sandpaper to it:

Improved disk turning tool

Snug the screw (a Torx T9 from the Small Drawer o’ Random M3 Screws) down on a rough-cut disk:

Improved disk turning tool – in use

Sissy cuts remain the order of the day, but the screw applies plenty of clamping force and doesn’t require the hulking live center.

2021-10-14

Dirt Devil Vacuum Tool Adapters

Being the domain expert for adapters between a new vacuum cleaner and old tools, this made sense (even though it’s not our vacuum):

Dirt Devil Nozzle Bushing - solid model — Dirt Devil Nozzle Bushing – solid model

The notch snaps into a Dirt Devil Power Stick vacuum cleaner and the tapered end fits a variety of old tools for other vacuum cleaners:

Dirt Devil Nozzle Bushing top view - solid model — Dirt Devil Nozzle Bushing top view – solid model

Having some experience breaking thin-walled adapters, these have reinforcement from a PVC tube:

Dirt Devil adapter - parts — Dirt Devil adapter – parts

A smear of epoxy around the interior holds the tube in place:

Dirt Devil adapters - assembled — Dirt Devil adapters – assembled

Building the critical dimensions with a 3D printed part simplified the project, because I could (and did!) tweak the OpenSCAD code to match the tapers to the tools. Turning four of those tubes from a chunk of PVC conduit, however, makes a story for another day.

The OpenSCAD source code as a GitHub Gist:

	// Dirt Devil nozzle adapter
	// Ed Nisley KE4ZNU 2021-10

	// Tool taper shift
	Finesse = -0.1; // [-0.5:0.1:0.5]

	// PVC pipe liner
	PipeOD = 28.5;

	/* [Hidden] */

	//- Extrusion parameters

	ThreadThick = 0.25;
	ThreadWidth = 0.40;

	HoleWindage = 0.2;

	function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit);

	Protrusion = 0.1; // make holes end cleanly

	//———————-
	// Dimensions

	TAPER_MIN = 0;
	TAPER_MAX = 1;
	TAPER_LENGTH = 2;

	Socket = [36.0,37.0,40.0];

	LockringDia = 33.5;
	LockringWidth = 4.5;
	LockringOffset = 2.5;

	Tool = [Finesse,Finesse,0] + [30.0,31.1,30.0];

	AdapterOAL = Socket[TAPER_LENGTH] + Tool[TAPER_LENGTH];

	NumSides = 36;
	$fn = NumSides;

	//———————-
	// 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(r=(FixDia + HoleWindage)/2,h=Height,$fn=Sides);

	}


	//——————-
	// Define it!

	module Adapter() {

	difference() {
	union() {
	difference() {
	cylinder(d1=Socket[TAPER_MIN],d2=Socket[TAPER_MAX],h=Socket[TAPER_LENGTH]);
	translate([0,0,LockringOffset])
	cylinder(d=2*Socket[TAPER_MAX],h=LockringWidth);
	}

	cylinder(d=LockringDia,h=Socket[TAPER_LENGTH]);
	translate([0,0,LockringOffset + 0.75*LockringWidth])
	cylinder(d1=LockringDia,d2=Socket[TAPER_MIN],h=0.25*LockringWidth);

	translate([0,0,Socket[TAPER_LENGTH]])
	cylinder(d1=Tool[TAPER_MAX],d2=Tool[TAPER_MIN],h=Tool[TAPER_LENGTH]);
	}
	translate([0,0,-Protrusion])
	PolyCyl(PipeOD,AdapterOAL + 2*Protrusion,NumSides);
	}

	}

	//———————-
	// Build it!

	Adapter();

view raw Dirt Devil Nozzle Bushing.scad hosted with ❤ by GitHub

The taper in the code almost certainly won’t fit whatever tool you have: measure thrice, print twice, and maybe fit once …

2021-10-06

Tag: Improvements

Alpha Geek Clock: Radome Update

LED-ified Halogen Desk Lamp: DC LED Driver

Alpha Geek Clock: Battery Refresh

CNC 3018 Tool Clamp Rehabilitation

Clearing the Noto Font Clutter: Again

Improved Mini-lathe Disk Turning Fixture

Dirt Devil Vacuum Tool Adapters