Machine Shop – Page 16 – The Smell of Molten Projects in the Morning

Cusinart Smart Stick Blender Motor Coupler

When our stick blender (Cusinart CSB-77, with an instruction manual dated 2011) failed, I dropped fifteen bucks on the shortest one we could find, which turned out to be inconveniently long for the shorter member of the user community. The old one recently emerged from the depths of the bench for triage; the failure was in the coupler between the motor and the blade shaft, but required complete disassembly before trying to repair it.

Pry out two obvious plastic plugs, remove two screws holding the top of the handle together, pull the handle apart, and reveal a PCB with a discrete diode bridge and an open-frame switch:

Stick blender coupler - PCB — Stick blender coupler – PCB

Fortunately, the wire colors matched my preconception. Unsolder the wires to get that side of the handle off.

Un-bend the tab holding the metal shell to the plastic frame and pull it off, whereupon the frame halves unsnap to release the motor:

Stick blender coupler - shell removed — Stick blender coupler – shell removed

The white nylon (?) coupler on the motor shaft pries off the splined motor shaft:

Stick blender coupler - motor shaft splines — Stick blender coupler – motor shaft splines

That black ring inside the coupler should be on the blade shaft:

Stick blender coupler - blade shaft — Stick blender coupler – blade shaft

It apparently got jammed in the coupler when the shaft’s drive dogs / splines (barely visible down inside) ripped up the coupler. I don’t know if that was a sudden failure or the end result of gradually accumulating damage, but the inside of the coupler was badly chewed up.

Dismantling the blade unit requires prying three plastic clips back, one at a time, while pushing upward on the intricate black plastic fitting around the shaft:

Stick blender coupler - blade housing clips — Stick blender coupler – blade housing clips

That let me ease a drop of oil down the shaft to what looks and feels like a plastic sleeve bearing near the blade end of the housing; oil should not be needed on a plastic bearing, but it definitely improved the bearing’s attitude. The snap ring securing the shaft is far enough away to prevent me from even trying to remove it, because I know there is no way I can reinstall it:

Stick blender coupler - blade shaft snap ring — Stick blender coupler – blade shaft snap ring

Some Xacto knife action removed the shredded plastic to reveal the remains of four slots for the blade shaft’s two drive dogs / splines:

Stick blender coupler - OEM coupler end view — Stick blender coupler – OEM coupler end view

Measuring All. The. Things. produced a reasonable solid model of the slots:

Stick Blender drive coupler - splines - solid model — Stick Blender drive coupler – splines – solid model

Removing those from a model of the coupler defined the shape:

Stick Blender drive coupler - PrusaSlicer — Stick Blender drive coupler – PrusaSlicer

As usual, having one in hand let me check the fit and, after a few tweaks, the next one was Just Right™.

The other end of the coupler is a simple cylinder sized for a firm press fit on the motor shaft splines:

Stick blender coupler - new coupler detail — Stick blender coupler – new coupler detail

My coupler is chunkier than the OEM coupler, because there was enough room in there and PETG-CF, being weaker than nylon, needs all the help it can get:

Stick blender coupler - new coupler installed — Stick blender coupler – new coupler installed

It’s one of the few things I’ve printed with 100% infill. If when that plastic fails, I’ll try something else.

Put the little rubber ring on the blade shaft and reassemble everything in reverse order:

Stick blender coupler - mating ends — Stick blender coupler – mating ends

The blender works as well as it ever did, while the halves couple and uncouple the way they should, so we’ll declare victory and keep the new blender as a backup.

The OpenSCAD source code as a GitHub Gist:

	// Stick Blender drive coupler
	// Ed Nisley – KE4ZNU
	// 2025-05-16

	include <BOSL2/std.scad>

	Layout = "Show"; // [Show,Build,Splines]

	/* [Hidden] */

	HoleWindage = 0.2;
	Protrusion = 0.1;
	NumSides = 334;

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

	ShellOA = [5.0,14.0,28.0]; // ID=motor shaft

	MixerSocket = [6.6,0,17.2]; // passes rubber retainer

	Retainer = [3.0,6.5,5.5]; // ID=mixer shaft,OD=rubber ring
	RetainerRebate = [Retainer[ID],3.9,1.5]; // … fits under shaft lip

	DriveSocket = [6.7,8.8,12.0]; // OD=notch OD
	DriveNotch = [(DriveSocket[OD] – DriveSocket[ID])/2,1.5,DriveSocket[LENGTH]]; // … drive notch shape on +X
	DriveChamfer = -DriveNotch.y;

	$fn = NumSides;

	//———-
	// Define Shapes

	module Splines() {
	render()
	for (a = [0:90:270])
	zrot(a)
	right(DriveSocket[ID]/2 – Protrusion)
	cuboid(DriveNotch + [Protrusion,0,0],chamfer=DriveChamfer,edges=[TOP+FWD,TOP+BACK],anchor=LEFT+BOTTOM);

	}

	module Coupler() {

	difference() {
	tube(ShellOA[LENGTH],id=ShellOA[ID],od=ShellOA[OD],anchor=BOTTOM);
	up(ShellOA[LENGTH] – MixerSocket[LENGTH])
	cyl(Retainer[LENGTH],d=Retainer[OD],anchor=BOTTOM);
	up(ShellOA[LENGTH] + Protrusion)
	cyl(DriveSocket[LENGTH] + Protrusion,d=DriveSocket[ID],anchor=TOP);
	up(ShellOA[LENGTH] – DriveNotch[LENGTH] + Protrusion)
	Splines();
	}
	}

	//———-
	// Build things

	if (Layout == "Splines")
	Splines();

	if (Layout == "Show")
	Coupler();

	if (Layout == "Build")
	Coupler();

view raw Stick Blender drive coupler.scad hosted with ❤ by GitHub

2025-05-19

Humidifier Float Clip Replacement

This being the end of the humidifcation season, I tried to set the longsuffering Sears Humidifier’s water level float to dry the thing out. After a few days, it became obvious that wasn’t working and I eventually found the clip intended to hold the float at the top of its travel had broken:

Humidifier float clips - on float — Humidifier float clips – on float

Building the retina-burn orange replacement started with a scan of the original:

The black segment at the bottom is a shadow due to the scanner’s light bar being offset from the imaging sensor.

Using GIMP, duplicate the remaining part of the latch, flip it left-to-right, then align it at the proper position:

Humidifier float clip - repaired — Humidifier float clip – repaired

The latch is the only tricky part and the ID of the ring is easy to locate, so (still in GIMP):

Trace the edge of the whole shape
Using Quick Mask mode, remove all but the latch
Convert the selection to a path
Export it as an SVG file

Then import it into OpenSCAD and eyeballometrically translate the shape to put the ring ID at the origin:

  color("Red")
    translate([-23.6,-42.6])
      import("Humidifier float clip - cabinet latch.svg");

Which looks like this:

Float clip - 2D latch — Float clip – 2D latch

Then glom a perfect ring onto it:

Float clip - 2D model parts — Float clip – 2D model parts

Extrude half an inch upward:

Float clip - extruded model — Float clip – extruded model

And It Just Works™:

Humidifier float clip - installed — Humidifier float clip – installed

There being no obvious affordance to get the ring over the two bumps in the float, I applied Channellock pliers to the float while easing the ring into place.

Re-rebuilding the hinges sits behind a few other things going on around here …

2025-05-15

Polymaker PolyDryer Box: PC4 Fitting Adapter

Having recently replaced the MMU3’s filament buffer with Polymaker PolyDryer boxes and auto-rewind spindles:

PolyDryer PC4 Fitting - Prusa MMU3 setup — PolyDryer PC4 Fitting – Prusa MMU3 setup

Their rubbery port covers work best with 6 mm OD PTFE tubes, but let the MMU3’s 4 mm tubes slide into / out of the boxes under normal filament extrusion / retraction forces, so I conjured an adapter for PC4-M10 pneumatic fittings:

PolyDryer PC4 Fitting - installed — PolyDryer PC4 Fitting – installed

A pair of M3 screws hold the adapter plate in place, with an EVA foam gasket sealing against the cover:

PolyDryer PC4 Fitting - interior view — PolyDryer PC4 Fitting – interior view

The PC4-M10 fittings let the 4 mm tubing slide right through, so the adapter has a 0.5 mm bottom sheet to block the tube, with a small hole for the filament:

PC4 Fitting Plates - bottom - solid model — PC4 Fitting Plates – bottom – solid model

You could use PC4-M6 fittings to block the tubing, but the 2 mm lumen on the fittings I have barely pass 1.75 mm nominal filament. Comments found elsewhere suggest identical PC4-M6 fittings have smaller lumens that snag the filament as it moves in one direction or the other.

The two blind holes get heat-staked 4×4mm M3 brass inserts.

The top has a threaded hole for the fitting:

PC4 Fitting Plates - top - solid model — PC4 Fitting Plates – top – solid model

Despite what the description says, the thread is not an M10 metric straight thread: it is a tapered pipe thread used for gas- and liquid-tight fittings. Considerable measurement & searching suggested a ⅛BSP-28 thread, because:

British Standard Pipe threads are used everywhere in the world except the USA
Both my metric tap sets have a ⅛BSP-28 tap along with all their hard-metric straight taps

The thread is painfully close to ⅛NPT-27, which would probably work in a pinch if it was the only tap you had.

Those PC4-M6 fittings might sport 1/16BSP-28 threads, but you’re on your own.

Further searching suggests nobody uses the corresponding tapered female pipe threads and everybody goes with a straight internal thread, so I conjured a stumpy threaded rod using the BOSL2 library and removed it from the adapter plate:

      threaded_rod(d=9.7,l=ThreadLength + Protrusion,pitch=INCH/28,internal=true,bevel2=true,anchor=BOTTOM);

The 9.7 mm diameter is the ⅛BSP-28 “major diameter”, rather than its “gauge diameter”, simply because it produced a good fit. The beveled top guides the fitting into the hole, but I still managed to cross-thread one.

The OpenSCAD code also produces SVG files to laser-cut the foam gasket and a drill template:

PolyDryer PC4 Fitting - drill template — PolyDryer PC4 Fitting – drill template

The holes were step-drilled to ⅛ inch (which has a historic relation to the ⅛BSP-28 size, because iron pipe) for a generous fit around the M3 screws.

That was way more complicated than I expected and I’m really glad to live in the future where this is a 3D printer project, not a metalworking project involving an actual tap in, say, steel.

The OpenSCAD source code as a GitHub Gist:

	// PC4 Fitting Plates for PolyDryer
	// Ed Nisley – KE4ZNU
	// 2025-05-02

	include <BOSL2/std.scad>
	include <BOSL2/threading.scad>

	Layout = "Plate"; // [Plate,Gasket,DrillGuide]

	/* [Hidden] */

	HoleWindage = 0.2;
	Protrusion = 0.1;
	NumSides = 334;

	Gap = 5.0;

	TubeStop = 0.5; // prevent PTFE tube from sliding through
	ThreadLength = 6.0;

	PlateOA = [28.0,22.0,ThreadLength + TubeStop];

	ScrewOC = 20.0;

	$fn=434;

	//———-
	// Define it

	module Plate() {

	difference() {
	cuboid(PlateOA,anchor=BOTTOM,rounding=4.0,edges="Z"); // plate to fit PolyDryer
	up(TubeStop) // thread for fitting
	threaded_rod(d=9.7,l=ThreadLength + Protrusion,pitch=INCH/28,internal=true,bevel2=true,anchor=BOTTOM);
	down(Protrusion)
	for (i = [-1,1])
	right(i*ScrewOC/2)
	cylinder(4.5 + TubeStop + Protrusion,d=3.7,anchor=BOTTOM); // M3 4×4 inserts
	down(Protrusion)
	cylinder(2*TubeStop,d=2.5,anchor=BOTTOM); // filament clearance
	}

	}

	//———-
	// Build things

	if (Layout == "Plate")
	Plate();

	if (Layout == "Gasket")
	projection(cut=true)
	Plate();

	if (Layout == "DrillGuide")
	difference() {
	projection(cut=true)
	Plate();
	circle(d=10);
	}

view raw PC4 Fitting Plates.scad hosted with ❤ by GitHub

2025-05-13

Anker LC-40 Flashlight Switch Repair

The switch on the Anker LC-40 flashlight serving as a running light on my Tour Easy became slightly intermittent before I replaced it with a 1 W amber LED, but it was still good enough to become the troubleshooting flashlight in the tray next to the Prusa Mk 4 printer. Eventually, of course, it failed completely and Something Had To Be Done.

Although I knew an exact replacement switch had to be available from the usual sources, I could not come up with a set of keywords capable of pulling them out of the chaff.

That was not a problem, because the assortment of SMD switches I used to replace the handlebar control caps on Mary’s Handi-Quilter HQ Sixteen contained push-on / push-off switches that were almost the right size:

Anker LC-40 Flashlight - switches and caps — Anker LC-40 Flashlight – switches and caps

Having recently convinced the MakerGear M2 3D printer to use TPU filament, all I had to do was produce a suitable cap to fit over the new switch in the flashlight’s tail:

Anker LC-40 Flashlight Button - TPU PrusaSlicer — Anker LC-40 Flashlight Button – TPU PrusaSlicer

Which turned into a multi-dimensional search over cap geometry, TPU extrusion speeds & feeds, and various impossible-to-directly-measure sizes:

Anker LC-40 Flashlight - TPU cap iterations — Anker LC-40 Flashlight – TPU cap iterations

The squarish block over on the left is PrusaSlicer’s version of a support structure wrapped around the first cap version; if human lives depended on it, I could surely extract the cap, but it would take a while.

The remaining ~~debris~~ samples occured while discovering:

An extruder temperature of 230 °C, not 250 °C, works well
A conical shape of the lip around the open end to eliminate the support structure
TPU doesn’t bridge well, so the closed end must be down
Length of the central pillar to barely touch the switch stem when released
Cap length and wall thickness so the TPU shell can collapse enough to actuate and release the switch stem
And so on and so on and scooby dooby dooby

Eventually I came up with a suitable combination:

Anker LC-40 Flashlight - switch caps — Anker LC-40 Flashlight – switch caps

Because I expected this would be an easy job, I used snap ring pliers to unscrew and rescrew the threaded retaining ring holding the switch PCB in place. Because the pliers didn’t have a stable grip on the ring, the threads eventually became just a bit goobered.

This was not a problem, because I have a(nother) 3D printer:

Anker LC-40 Flashlight Retainer - show view — Anker LC-40 Flashlight Retainer – show view

The gray thing on the right is a simple pin wrench fitting both the original and the replacement retaining rings, so I can orient the rings properly while unscrewing & rescrewing:

Anker LC-40 Flashlight - pin wrench in place — Anker LC-40 Flashlight – pin wrench in place

The threads have a 0.75 mm pitch and, while it’s possible to print screw threads, even a tedious 0.1 mm layer height would define each turn of the thread with only 7-½ layers.

This was not a problem, because I have a mini-lathe:

Anker LC-40 Flashlight - thread cutting — Anker LC-40 Flashlight – thread cutting

The yellow & green things on the left of those solid models are the fixture holding a retaining ring for threading and the washer applying pressure to keep the ring in place:

Anker LC-40 Flashlight - lathe fixture - detail — Anker LC-40 Flashlight – lathe fixture – detail

The alert reader will note that washer lacks holes for the alignment pins I added after seeing the washer sit not quite concentric on the fixture. I could call it continuous product improvement, although I doubt I’ll print another one.

Setting up the lathe involved finding the proper set of change gears, including the vital 42-50 stacked gear I made a while ago to print metric threads on a hard-inch lathe:

Anker LC-40 Flashlight - lathe change gear train — Anker LC-40 Flashlight – lathe change gear train

Although you’re supposed to measure the thread spacing on a skim pass, I find it’s easier to just measure the carriage movement for one spindle rotation:

Anker LC-40 Flashlight - lathe gear check — Anker LC-40 Flashlight – lathe gear check

A few passes produced a fine retaining ring:

Anker LC-40 Flashlight - pin wrench - detail — Anker LC-40 Flashlight – OEM vs lathe-cut threads

Sporting much nicer looking threads than the goobered original:

Anker LC-40 Flashlight - OEM vs lathe-cut threads — Anker LC-40 Flashlight – OEM vs lathe-cut threads

The original switch had a stabilizing ring around the body to prevent it from wobbling under the original rubber cap.

This was not a problem, because I have a laser cutter:

Anker LC-40 Flashlight - new switch in stabilizer — Anker LC-40 Flashlight – new switch in stabilizer

Those came from a scrap of fluorescent acrylic.

The wave washer behind the acrylic stabilizer improves the contact between the PCB trace around the rim and the flashlight tailcap, with the current passing through the body to the “light engine” up front. The retaining ring provides enough pressure to compress the wave washer, which is why it’s so easily goobered without a close-fitting pin wrench.

With everything assembled in reverse order, the flashlight worked pretty much as it did back when it was new:

Anker LC-40 Flashlight - TPU cap installed — Anker LC-40 Flashlight – TPU cap installed

However, after describing this during a recent SquidWrench meeting, I discovered that adding “latching” to my keywords surfaced a bodacious assortment of flashlight switches, so (a few days later) I removed the not-quite-right switch and replaced it with an identical twin of the OEM switch requiring just a little lead forming to fit the PCB.

Even better, using the 3D printed pin wrench to screw the original retaining ring into the flashlight’s aluminum threads a few times re-formed (unrelated to recent electrolytic capacitor reforming) its goobered threads well enough to fit and work perfectly again.

So I have:

… reassembled the flashlight with more-or-less original components
… a repair tool kit ready when another LC-40 fails
… re-learned the lesson that any time spent making a fixture or a special tool is not deducted from one’s allotment

And I loves me a happy ending or two!

The OpenSCAD source code as a GitHub Gist:

	// Anker LC-40 flashlight switch retainer
	// Ed Nisley – KE4ZNU
	// 2025-05-05

	include <BOSL2/std.scad>

	Layout = "Show"; // [Show,Build,Retainer,Fixture,Washer,Wrench]

	Gap = 5; // [0:10]

	/* [Hidden] */

	HoleWindage = 0.2;
	Protrusion = 0.1;
	NumSides = 334;

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

	$fn=334;

	Plate = [16.8,20.0,3.0]; // retainer plate, OD allows for lathe threading
	PlateRecessDepth = 1.6;
	PlateInnerThick = Plate[LENGTH] – PlateRecessDepth;
	ClearID = 11.0;

	PinOD = 3.0;
	PinOC = 12.0;

	WrenchLength = 25.0; // handle on wrench
	JawLength = 22.0; // lathe jaw
	ThreaderOverrun = 10.0; // stick-out for threading tool clearance
	ThreadAllowance = 2*1.0; // clearance for thread depth

	//———-
	// Define Shapes

	module Retainer() {

	difference() {
	tube(Plate[LENGTH],od=Plate[OD],id=ClearID,anchor=BOTTOM);
	up(Plate[LENGTH] + Protrusion)
	cyl(PlateRecessDepth + Protrusion,d=Plate[ID],anchor=TOP);
	down(Protrusion)
	hull()
	for (i = [-1,1])
	right(i*PinOC/2) down(Protrusion)
	cyl(Plate[LENGTH] + Protrusion,d=PinOD,anchor=BOTTOM);
	}

	}

	module Fixture() {

	difference() {
	regular_prism(6,h=JawLength,d=1.2*Plate[OD],anchor=BOTTOM) position(TOP) {
	cyl(PlateRecessDepth + ThreaderOverrun,d=Plate[ID],anchor=BOTTOM);
	cyl(Plate[LENGTH] + ThreaderOverrun,d=ClearID,anchor=BOTTOM);
	// hull()
	for (i = [-1,1])
	right(i*PinOC/2)
	cyl(Plate[LENGTH] + ThreaderOverrun + Plate[LENGTH]/2,d=PinOD,anchor=BOTTOM);
	cyl(ThreaderOverrun,d=Plate[OD] – ThreadAllowance,anchor=BOTTOM);
	}
	up(JawLength + ThreaderOverrun + Plate[LENGTH] + Protrusion) // M4 burly insert
	cyl(10.0 + 5,d=5.5,anchor=TOP);
	}
	}

	module Washer() {

	difference() {
	tube(Plate[LENGTH],od=Plate[OD] – ThreadAllowance,id=4.5,anchor=BOTTOM);
	down(Protrusion)
	for (i = [-1,1])
	right(i*PinOC/2)
	cyl(2*Plate[LENGTH],d=PinOD,anchor=BOTTOM);
	}
	}

	module Wrench() {

	difference() {
	union() {
	cyl(WrenchLength,d=Plate[ID],anchor=BOTTOM);
	for (i = [-1,1])
	right(i*PinOC/2)
	cyl(WrenchLength + Plate[LENGTH],d=PinOD,anchor=BOTTOM);
	}
	down(Protrusion)
	cyl(2*WrenchLength,d=ClearID – 2.0,anchor=BOTTOM);
	}
	}

	//———-
	// Build things

	if (Layout == "Retainer")
	Retainer();

	if (Layout == "Fixture")
	Fixture();

	if (Layout == "Washer")
	Washer();

	if (Layout == "Wrench")
	Wrench();

	if (Layout == "Show") {
	color("Gold")
	Fixture();
	up(JawLength + ThreaderOverrun + Gap)
	zflip(z=Plate[LENGTH]/2)
	Retainer();
	color("Green")
	up(JawLength + ThreaderOverrun + Plate[LENGTH] + 2*Gap)
	Washer();

	right(40) {
	zflip(z=Plate[LENGTH]/2)
	Retainer();
	color("Silver")
	up(Plate[LENGTH] + Gap)
	zflip(z=WrenchLength/2)
	Wrench();
	}
	}

	if (Layout == "Build") {
	Fixture();
	right(1.5*Plate[OD]) {
	Retainer();
	fwd(1.5*Plate[OD])
	Retainer();
	}
	left(1.5*Plate[OD])
	Washer();
	fwd(1.5*Plate[OD])
	Wrench();
	}

view raw Anker LC-40 Flashlight Retainer.scad hosted with ❤ by GitHub

2025-05-12

Delta Shower Head Holder Extension

The original shower head being too far overhead for Mary’s reach, I installed a Delta ProClean Shower Head which would also be too high. It has a hose, which means I can adjust the height:

The InterWebs offer several 3D-printable versions of such a thing, but Delta offers many different shower heads, some of which are visually (to my eyes, anyway) indistinguishable from the 75740SN you see here. The model I tried did not fit the holder I have, so I conjured one from the vasty digital deep:

Delta shower head holder extension - solid model — Delta shower head holder extension – solid model

It builds standing on that tidy cutoff:

Delta shower head holder extension - PrusaSlicer warning — Delta shower head holder extension – PrusaSlicer warning

Despite PrusaSlicer’s kvetching about the “collapsing overhang” inside the socket, it came out fine.

The shower head is still slightly too high for her, but now I can print another one with a longer offset and a slightly smaller plug to fit deeper in the OEM socket.

Worst case, there’s a wall-mounted holder to put the shower head at shoulder height.

The OpenSCAD source code as a GitHub Gist:

	// Delta shower head holder extension
	// Ed Nisley – KE4ZNU
	// 2025-05-02

	include <BOSL2/std.scad>

	Layout = "Show"; // [Show,Build,Plug,Socket,Connector]

	MountAngle = 30; // between OEM and new holder
	MountOffset = 20.0;

	/* [Hidden] */

	HoleWindage = 0.2;
	Protrusion = 0.1;
	NumSides = 334;

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

	Insert = [21.0,24.5,35.0]; // hose connector taper
	PlugSize = Insert + [-0.3,-0.3,0]; // … for better fit in OEM holder

	Slot = [Insert[OD],14.6,3*Insert[LENGTH]]; // slot on OEM holder, arbitrary length

	WallThick = 8.0; // holder wall thickness
	Radius = 3.0; // shapely rounding

	$fn=NumSides;

	//———-
	// Define Shapes

	module Plug() {

	cyl(l=Insert[LENGTH],d1=PlugSize[ID],d2=PlugSize[OD],anchor=BOTTOM);

	}

	module Socket() {

	difference() {
	tube(l=Insert[LENGTH],id1=Insert[ID],id2=Insert[OD],wall=WallThick,anchor=BOTTOM);
	cuboid(Slot + [0,1.0,0],anchor=LEFT+CENTER);
	right(Insert[OD]/2)
	cube([Insert[OD],Insert[OD] + 2WallThick,3Insert[LENGTH]],anchor=LEFT+CENTER);
	}

	}

	module Connector() {

	difference() {
	left(MountOffset)
	cuboid([MountOffset + Insert[LENGTH]sin(MountAngle),Slot.y,Insert[LENGTH]cos(MountAngle)],
	anchor=LEFT+BOTTOM);
	yrot(MountAngle) right(Insert[ID]/2 + WallThick)
	cyl(l=Insert[LENGTH],d1=Insert[ID] + 2WallThick,d2=Insert[OD] + 2WallThick,anchor=BOTTOM);

	}

	}

	module Adapter() {

	union() {
	left(MountOffset)
	Plug();
	yrot(MountAngle) right((Insert[ID] + 2*WallThick)/2)
	Socket();
	Connector();
	}
	}

	//———-
	// Build things

	if (Layout == "Plug")
	Plug();

	if (Layout == "Socket")
	Socket();

	if (Layout == "Connector")
	Connector();

	if (Layout == "Show")
	Adapter();

	if (Layout == "Build")
	up(Insert[ID]/2 + 1*WallThick + Insert[OD]/2)
	yrot(90-MountAngle)
	Adapter();

view raw Delta shower head holder extension.scad hosted with ❤ by GitHub

2025-05-05

HQ Sixteen: Improved Control Cap Wiring

The new control caps on the HQ Sixteen’s handlebars have three switches apiece:

HQ Sixteen - grip cap installed - left — HQ Sixteen – grip cap installed – left

A six-conductor ribbon cable brings those switch terminal through the handlebars, across the smaller PCBs where the original switches plugged in, and atop the main PCB behind / under the LCD panel where they get wired together:

The gray ribbon cable carries power for the LEDs and returns the original switch signals formerly plugged into one of the four-pin headers on the right PCB. The same PCB is used on the other side and the switches over there plug into the other header.

The central PCB is also used for the rear handlebars, which do not have the smaller PCBs, and those switch cables plug directly into four-pin headers mounted instead of the headers for the gray ribbon cables:

Some probing and doodling produced a diagram of the switch connections:

HQ Sixteen - Control Button Wiring — HQ Sixteen – Control Button Wiring

Working with the handlebars either inverted or flipped left-for-right on the workbench makes this far more confusing than it really should be.

In any event, the bottom diagram shows the connections between the two four-pad header positions on the central PCB and the two six-pin headers for the new switches. I used a 2×6 pin header block to plug in the new switches, connected the pins with soldered Wire-Wrap wire, and used three-wire ribbon cable to the PCB pads.

The general idea was to duplicate the Start-Stop and Needle Up/Down switches on both sides, while maintaining the same relative positions of the Fast / Slow switches. In effect, the two new switches on each side are wired in parallel to the original switch pads on the PCB.

Surprisingly, I got the three-wire ribbon cables from the four-pad headers right on the second try, which involved flipping it over. The top and bottom pads on those headers are connected together, so the three-wire cable can go on either way to reverse the positions of the other two wires.

And then the new switches Just Worked™ … whew!

2025-05-02

HQ Sixteen: Improved Control Cap Final Assembly

My version of the Handi-Quilter HQ Sixteen grip control caps requires some assembly:

Control Button Caps - solid model - build view — Control Button Caps – solid model – build view

Getting the OEM caps off the handlebars required carefully applying torque through a strap wrench, but they eventually came free:

HQ Sixteen - OEM grip cap - screw holes — HQ Sixteen – OEM grip cap – screw holes

I don’t know what the unused screw hole between the two gnarly holes was for; perhaps they discovered one hole was inadequate.

The alert reader will note the two screw holes are not the same distance from the end of the tube, which required rebuilding the plug model to match:

Control Button Caps - solid model - plug holes — Control Button Caps – solid model – plug holes

Which is why I didn’t glue the plug into the cap before I got the OEM caps off.

Redrill the tube holes to 3 mm, file the burrs from both the OEM and my drilling, smooth the edges, and the plug fit perfectly. Then I seated the M3 square nuts behind those hole and, after installing the new plugs in the handlebars, glued the caps in place with a simple fixture to ensure the front faced forward:

- HQ Sixteen - grip cap faceplate gluingHQ Sixteen - grip cap gluing — – HQ Sixteen – grip cap faceplate gluingHQ Sixteen – grip cap gluing

The clamp gently compresses the foam enough to hold the flats against the bench block while the JB Plastic Bonder cures.

After verifying all the buttons worked, I glued the faceplates to the cap bodies:

HQ Sixteen - grip cap faceplate gluing — HQ Sixteen – grip cap faceplate gluing

The tape held the faceplate in place while I snugged the clamps.

Modulo my weak graphic design skills, the caps look pretty good:

HQ Sixteen - grip cap installed - right — HQ Sixteen – grip cap installed – right

And, after a bit of wiring yet to be described, the buttons do exactly what their legends suggest:

The white sheet with feeble graphics can be peeled off, so I have another chance to tart it up.

The overall idea was to replace the failing Start/Stop switch while duplicating that switch on both caps. While I was at it, I also duplicated the Needle Up/Down button, because who wants asymmetric caps?

Mary is assembling another quilt and the new switches will get plenty of action …

2025-05-01

Category: Machine Shop

Cusinart Smart Stick Blender Motor Coupler

Humidifier Float Clip Replacement

Polymaker PolyDryer Box: PC4 Fitting Adapter

Anker LC-40 Flashlight Switch Repair

Delta Shower Head Holder Extension

HQ Sixteen: Improved Control Cap Wiring

HQ Sixteen: Improved Control Cap Final Assembly