MK4 – Page 9 – The Smell of Molten Projects in the Morning

WS-5000 Anemometer Bird Spike Ring

A critter made off with our battered plastic rain gauge, so I set up an Ambient Weather WS-5000 station to tell Mary how much rain her garden was getting. I added the Official Bird Spike Ring around the rain gauge to keep birds off, but robins began perching atop the anemometer while surveying the yard and crapping on the insolation photocell.

After a few false starts, the anemometer now has its own spikes:

It’s a snugly fitting TPU ring:

Weather Station Spikes - build test piece — Weather Station Spikes – build test piece

The spikes are Chromel A themocouple wire, because a spool of the stuff didn’t scamper out of the way when I opened the Big Box o’ Specialty Wire. As you can tell from the picture, it’s very stiff (which is good for spikes) and hard to straighten (which is bad for looking cool).

The shape in the middle is a hole diameter test piece. Next time around, I’ll use thicker 14 AWG copper wire:

Weather station spikes - test piece — Weather station spikes – test piece

The test piece showed I lack good control over the TPU extrusion parameters on the Makergear M2, as holes smaller than about 2 mm vanish, even though the block’s outside dimensions are spot on. This application wasn’t too critical, so I sharpened the wire ends and stabbed them into the middle of the perimeter threads encircling the hole.

Now we’ll discover how TPU survives weather.

The OpenSCAD source code as a GitHub Gist:

	// Ambient Weather – Ambient Weather WS-5000 anemometer bird spike ring
	// Ed Nisley – KE4ZNU
	// 2025-06-09

	include <BOSL2/std.scad>

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

	/* [Hidden] */

	HoleWindage = 0.2;
	Protrusion = 0.1;

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

	SpikeOC = 30.0; // straight-line distance between spikes, OEM = 35

	WallThick = 4.0;

	BandID = 3.5*INCH – 0.5; // = OD of weather station
	BandOD = BandID + 2*WallThick;

	BandHeight = 8.0;

	SpikeOD = 1.7 + HoleWindage; // wire diameter
	SpikeWall = 2.0; // around wires

	SpikeBCD = BandOD;

	MountOD = SpikeOD + 2*SpikeWall;

	NumSpikes = ceil(PI*BandOD/SpikeOC); // need integral number of spikes
	SpikeAngle = 360/NumSpikes;
	NumSides = 3*NumSpikes;

	echo(SpikeAngle=SpikeAngle);
	echo(NumSpikes=NumSpikes);


	//———-
	// Define Shapes

	module Slice() {

	difference() {
	hull() {
	pie_slice(h=BandHeight,d=BandOD,$fn=NumSides,ang=SpikeAngle,spin=-SpikeAngle/2,anchor=BOTTOM);
	right(SpikeBCD/2 – MountOD/2)
	cyl(h=BandHeight,d=MountOD,realign=true,anchor=LEFT+BOTTOM,$fn=2*6);
	}
	down(Protrusion) {
	cyl(h=BandHeight + 2*Protrusion,d=BandID,$fn=NumSides,circum=true,realign=true,anchor=BOTTOM);
	right(SpikeBCD/2)
	cyl(h=BandHeight + 2*Protrusion,d=SpikeOD,$fn=6,circum=true,realign=true,anchor=BOTTOM);
	}
	}

	}

	module SpikeRing() {

	for (i=[0:NumSpikes-1])
	zrot(i*SpikeAngle)
	Slice();


	}

	//———-
	// Build things

	if (Layout == "Slice") {
	Slice();
	}


	if (Layout == "Show") {
	left(SpikeBCD/2)
	Slice();
	SpikeRing();
	}

	if (Layout == "Build") {
	SpikeRing();
	}

view raw Weather Station Spikes.scad hosted with ❤ by GitHub

2025-06-12

PolyDryer Internal Fan Puzzle

With the humidity inside the PolyDryer boxes being roughly proportional to the amount of filament on the spool, I printed a slightly modified airlock plate and a TPU seal ring, then stuck a tiny fan on it:

PolyDryer airlock plate - tiny fan — PolyDryer airlock plate – tiny fan

It just barely clears the curved air guide inside:

PolyDryer airlock plate - tiny fan installed — PolyDryer airlock plate – tiny fan installed

The tea bags full of desiccant allow some wind between them and the filament in the spool, but I obviously must re-think that setup. There’s enough clearance for what should be reasonable circulation, so i defined it to be good enough for now.

The box of TPU started at 25 %RH, dropped to 22 %RH overnight, then returned to 25 %RH the next day:

PolyDryer TPU - 25 pct RH — PolyDryer TPU – 25 pct RH

Now that I’m watching more often, I’ve seen the meter glitch to 10% for a few seconds:

PolyDryer TPU - 10 pct RH glitch — PolyDryer TPU – 10 pct RH glitch

A humidity indicator card suggests the air is under 20 %RH:

PolyDryer TPU - humidity indicator card — PolyDryer TPU – humidity indicator card

It may be the filament can outgas water vapor as rapidly as the desiccant can remove it, but I expected the fan to make at least a little difference.

I have no idea what’s going on in those boxes.

2025-06-10

PolyDryer Humidity vs. Spool Fill

The Basement Shop has 50±5% relative humidity, with the top held down by a hulking dehumidifier (plus a box fan stirring the air) and the bottom supported by being a basement. As a result, the 3D printer filament stabilized at about 50% RH, which seemed to work well enough for PETG.

Adding TPU to the stable called for better humidity control, so I set up a bunch of PolyMaker PolyDryer boxes with Auto-rewind spindles.

After a few weeks, though, I didn’t expect this:

That’s activated alumina desiccant, mostly because it’s reputed to have more capacity and a lower ultimate humidity than silica gel, but it likely doesn’t make much difference.

In addition to 25 g of desiccant in the PolyDryer meter case, I dropped five teabags holding 10 g each in the bottom of the box for more capacity. I measure the desiccant by putting 75.0 g into a cup, putting 25.0 g in the PolyDryer meter box (aided by a Polydryer Desiccant Funnel), 10.0 g into four teabags, and whatever’s left into the fifth teabag, thus eliminating rounding errors in the smaller quantities.

The stabilized humidity inside the boxes seems to depend on the amount of filament on the spool:

Nearly full → 25% to 30% RH
Half full → 20%-ish RH
Nearly empty → 10% to 15% RH

I think the humidity level comes from the filament outgassing water vapor through its (limited) surface area on the outer layer around the spool. The difference between that rate and the desiccant’s ability to remove water vapor from the (unmoving) air in the box sets the stable humidity: more surface area → more water vapor → higher humidity.

After the filament eventually dries out, the humidity should decrease, but diffusion is a slow process. More likely, the humidity will remain stable as the printer pulls filament from the outer layer and exposes the somewhat wetter plastic within.

The heater and fan inside the PolyDryer base unit circulates hot air through the box around the spool, but depends on the desiccant to remove water vapor. Running the base unit for 6 or 12 hours makes little difference in the stabilized humidity, so I think the desiccant is doing the best it can as the filament outgasses more water vapor.

Using Air Exchanger vents seems to make no difference, likely because the desiccant must then pull more water vapor out of the incoming 50% RH basement air. A psychrometric chart says 50% RH air at 60 °F becomes 10% RH air at 120 °F, but moisture in the filament wrapped around the spool can’t escape any faster.

So, for example, a full spool of TPU starting at 25% RH:

PolyDryer humidity - TPU start — PolyDryer humidity – TPU start

Six hours of drying pulls it down to 22%:

PolyDryer humidity - TPU finish — PolyDryer humidity – TPU finish

After sitting overnight it’s back at 25%:

PolyDryer humidity - TPU after 14 hr — PolyDryer humidity – TPU after 14 hr

Admittedly, that was with the vents in place, but the closed box started at 25% RH after sitting around for a week or so following a similar drying cycle.

The desiccant had absorbed 4 g of water since I put it in, so it hasn’t been entirely idle.

Which suggests 75 g of activated alumina desiccant is workin’ hard and doin’ swell in there, with the filament acting as an essentially infinite reservoir of water vapor.

I haven’t noticed any particular difference in PETG print quality and the TPU hasn’t gotten enough mileage to notice much trouble, but reducing the MMU3 buffer clutter was totally worth the effort.

2025-06-02

HQ Sixteen: Nose Ring Lights

We don’t know what the proper term might be for this part of the machine, but it looks sorta like a nose and the lights form most of a ring around it, so I’m going with “Nose Ring Lights”:

The general idea is to put more light on the quilt than the Chin Light, which looked pretty good until the COB LED strip started flickering as the LEDs failed.

Handi-Quilter sells a ring light for machines manufactured a decade later than ours, but it uses a built-in USB jack this machine lacks.

One of two (apparently) unused M4 holes on the left side of the machine frame suggested a mounting point for a 3D printed bracket:

HQ Sixteen Nose Ring Lights - solid model — HQ Sixteen Nose Ring Lights – solid model

The ramp matches the 3° (-ish) mold draft of the machine frame, which I initially ignored by angling the tab, but a tilted frame looked awful; it’s now aligned with local horizontal..

A few iterations got all the pieces & holes in their proper places:

HQ Sixteen Nose Ring lights - iterations — HQ Sixteen Nose Ring lights – iterations

The smaller (rampless) bracket has three LED strips, but a quick test showed more light would be better:

HQ Sixteen Nose Ring lights - bottom view — HQ Sixteen Nose Ring lights – bottom view

The lack of a transparent-ish cover is obviously unsuitable for a commercial product, but the key design goal is to not interfere with spreading as much light as possible across as much of the quilt as possible. The black JB Weld Plastic Bonder blobs keep the 24 VDC supply out of harm’s way, which is as good as it needs to be for now.

The bracket has three sides, because the right side of the machine has all the thread guide hardware. Putting anything over there seemed likely to interfere with either thread movement or fingers making adjustments.

Fortunately, the wider bracket doesn’t stick out too far beyond the machine frame and the doubled LED strips create a much smoother light pool:

HQ Sixteen Nose Ring lights - left front view — HQ Sixteen Nose Ring lights – left front view

Yes, the quilt is focused and the LED frame is blurred.

The larger light-emitting area reduces the shadow under the left rod (supporting the ruler foot) enough to be unobjectionable.

A 0.2 mm layer thickness transforms the smooth ramp into stair steps:

HQ Sixteen Nose Ring Lights - PrusaSlicer — HQ Sixteen Nose Ring Lights – PrusaSlicer

They’re inconspicuous after the bracket is installed.

The Chin Light ran on 12 V and these strips require 24 V, so the OpenSCAD code creates a pair of endcaps for the new supply, which is of course completely different than the old supply. Setting that up must await quilt completion.

The OpenSCAD source code as a GitHub Gist:

	// HQ Sixteen Nose Ring Lights
	// Ed Nisley – KE4ZNU
	// 2025-05-23

	include <BOSL2/std.scad>

	Layout = "Show"; // [Show,Build,NosePlan,PowerCap]

	// Number of side-by-side LED strips
	Strips = 2;

	/* [Hidden] */

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

	$fn=NumSides;

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

	Gap = 5.0;

	WallThick = 5.0; // default thickness for things

	NoseRadius = 6.0; // corner roundoff

	NoseOA = [44.0,36.5]; // overall nose size
	NoseAngles = [87,87]; // front & rear inward angles wrt left side

	NoseCenters = [ // centers of circles defining the nose corners
	[NoseRadius, NoseOA.y/2 – NoseRadius],
	[NoseRadius,-(NoseOA.y/2 – NoseRadius)],
	[NoseOA.x – NoseRadius, NoseOA.y/2 – NoseRadius – (NoseOA.x – 2NoseRadius)tan(90 – NoseAngles[0])],
	[NoseOA.x – NoseRadius,-(NoseOA.y/2 – NoseRadius – (NoseOA.x – 2NoseRadius)tan(90 – NoseAngles[1]))],
	];

	LEDMargin = 1.0;
	LEDStrip = [41.5 + LEDMargin,8.0 + LEDMargin,1.8 + 0.2]; // 24 V COB LED strip unit + windage
	LEDBaseOA = [LEDStrip.x + StripsLEDStrip.y,NoseOA.y + 2Strips*LEDStrip.y,WallThick]; // LED mount

	DraftAngle = 3.0; // angle of frame wrt horizontal at right end of nose
	DraftWedge = [NoseOA.x,NoseOA.y + 2LEDStrip.y,NoseOA.xtan(DraftAngle)];

	HoleOffset = [-10.0,5.5,DraftWedge.z + 10.0]; // from left front corner of nose
	HolePosition = HoleOffset + [0,-NoseOA.y/2,WallThick]; // absolute coordinates from origin

	Screw = [4.0 + HoleWindage,9.0,2.0]; // LENGTH=button head

	Bracket = [WallThick,Screw[OD] + 4.0,HoleOffset.z + Screw[OD/2] + 2.0 + WallThick];

	Supply = [46.0,30.0,21.0]; // 24 VDC power supply
	SupplyScrewOffset = 5.0; // … M4 screw hole from end of supply case

	CapWall = 3.0;
	CapRadius = CapWall – 1.0;
	CapInset = 1.0;
	CapOA = [20.0,Supply.y + 2*CapWall,Supply.z + CapWall]; // x & y to cover existing holes

	//———-
	// Define Shapes

	//—– 2D outline of nose piece just under frame casting

	module NosePlan() {
	hull()
	for (p = NoseCenters)
	translate(p) circle(r=NoseRadius);
	}

	//—– LED mounting plate

	module Mount() {

	union() {
	difference() {
	union() {
	right(LEDBaseOA.x/2 – Strips*LEDStrip.y)
	cuboid(LEDBaseOA,rounding=WallThick/2,except=BOTTOM,anchor=BOTTOM);
	up(LEDBaseOA.z) left(-HoleOffset.x/2)
	yrot(DraftAngle)
	cuboid(DraftWedge,rounding=WallThick/2,edges="Z",anchor=LEFT+BOTTOM);
	}
	down(Protrusion)
	linear_extrude(LEDBaseOA.z + DraftWedge.z + Protrusion)
	NosePlan();
	if (Strips > 1)
	translate([HolePosition.x – Bracket.x/2,HolePosition.y – Bracket.y,-Protrusion])
	cyl(LEDBaseOA.z + 2*Protrusion,d=4.0,anchor=BOTTOM);
	}
	difference() {
	union() {
	translate([HolePosition.x,HolePosition.y,(Bracket.x/2)*sin(DraftAngle)])
	left(Bracket.x)
	cuboid(Bracket,rounding=WallThick/2,edges=LEFT,anchor=BOTTOM+LEFT);
	translate([HolePosition.x – Bracket.x/2,HolePosition.y,0]) // rounding filler
	cuboid([LEDStrip.y,Bracket.y,WallThick],anchor=BOTTOM+LEFT);
	}
	translate(HolePosition)
	xrot(180/6) xcyl(l=NoseOA.x,d=Screw[ID],$fn=6);
	}
	}
	}

	//—– Endcap for power supply

	module EndCap() {

	difference() {
	cuboid(CapOA,rounding=CapRadius,except=BOTTOM,anchor=LEFT+BOTTOM);
	right(CapOA.x – CapWall) down(Protrusion)
	cuboid(Supply + [0,0,Protrusion],anchor=RIGHT+BOTTOM);
	right(CapInset + SupplyScrewOffset)
	zcyl(l=2*CapOA.z,d=Screw[ID],$fn=6,anchor=BOTTOM);
	}

	}


	//———-
	// Build things

	if (Layout == "NosePlan") {
	NosePlan();
	}

	if (Layout == "PowerCap") {
	EndCap();
	}

	if (Layout == "Show") {
	Mount();

	ctr = 80;
	ofs = Supply.x/2 – CapInset;
	left(ctr – ofs)
	EndCap();
	left(ctr + ofs)
	xflip()
	EndCap();
	color("Silver",0.6)
	left (ctr)
	cuboid(Supply,anchor=BOTTOM);
	}

	if (Layout == "Build") {
	Mount();
	back((LEDBaseOA.y + CapOA.y)/2 + Gap) right(Gap) up(CapOA.z) zflip()
	EndCap();
	back((LEDBaseOA.y + CapOA.y)/2 + Gap) left(Gap) zrot(180) up(CapOA.z) zflip()
	EndCap();
	}

view raw HQ Sixteen Nose Ring Lights.scad hosted with ❤ by GitHub

2025-05-30

Sears Humidifier: Lid Hinge Re-repair

The longsuffering Sears Humidifier that Came With The House once again has functioning hinges:

Sears Humidifier - lid hinge gluing setup — Sears Humidifier – lid hinge gluing setup

That’s the gluing “fixture” with enough steel piled on the lid to keep it from moving and machinist vises pushing / holding the hinge fragments in place.

I used the same technique as before, with duct tape aligning the loose pieces and JB Plastic Bonder sticking them together:

Sears Humidifier - right hinge outboard — Sears Humidifier – right hinge outboard

The other side of that hinge shows the broken section at the end of the molded void:

Sears Humidifier - right hinge inboard — Sears Humidifier – right hinge inboard

The other hinge has a 3D printed replacement end:

Sears Humidifier - left hinge inboard — Sears Humidifier – left hinge inboard

The other side shows there’s not much of the original hinge left:

Sears Humidifier - left hinge outboard — Sears Humidifier – left hinge outboard

I very carefully installed the lid on the newly cleaned humidifier in the Basement Shop, where it flips up and down like anything.

At the start of this year’s humidification season, I will very carefully carry the lid up the basement stairs to the Sewing Room and we’ll see how long it survives in actual use.

2025-05-28

3D Printer Filament Spool Washers

The auto-rewind spindles for PolyDryer boxes fit a variety of spools, but recessed hubs like this require a pair of washers to center the spindles:

Filament spool washers - recessed hub — Filament spool washers – recessed hub

They’re laser-cut, although you could print them easily enough:

Filament spool washers - recessed hub - installed — Filament spool washers – recessed hub – installed

The size for that particular spool:

OD = 80 mm
Flange side ID = 51 mm
Nut side ID = 43
Thickness = ¼ inch, near enough

Other spools required a 3 mm shim on the flange side to sit centered in the PolyDryer boxes. Those are basically identical what you see above, with a 72 mm OD matching the flange.

The PETG-CF filament arrived on cardboard spools, which are apparently the new hotness:

Filament spool washers - printed — Filament spool washers – printed

The 56 mm spool ID requires adapters on both sides, with the flange side getting a 4 mm shim:

Filament spool washers - printed shim - flange side — Filament spool washers – printed shim – flange side

That skootches the spool over against the 1 mm shim on the nut side:

Filament spool washers - printed - nut side — Filament spool washers – printed – nut side

It would be possible to modify the auto-rewind spindle diameters to suit, if you were a dab hand with Fusion360, but the variety of hubs around here tells me a set of cheap adapters & shims makes more sense.

You should not assume anything will fit the spools you have, no matter how much they resemble what you see above.

The OpenSCAD source code as a GitHub Gist:

	// Polymaker PolyDryer auto-rewind spool washers
	// Ed Nisley – KE4ZNU
	// 2025-05-20

	include <BOSL2/std.scad>

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


	/* [Hidden] */

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

	$fn=NumSides;

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

	Gap = 5.0; // Build separation
	SpoolWidth = 20.0; // Show separation

	FlangeOD = 72.0; // auto-rewind spindle
	FlangeHubOD = 50.5 + 1.0;
	NutOD = 77.0;
	NutHubOD = 42.0 + 1.0;


	//———-
	// Define Shapes

	module EryOneCF(Side = "Flange") {

	SpoolID = 56.0 – 1.0;
	SpoolSideThick = 3.0;

	if (Side == "Flange")
	tube(4.0,od=FlangeOD,id=FlangeHubOD,anchor=BOTTOM) // flange side
	position(TOP)
	tube(SpoolSideThick,od=SpoolID,id=FlangeHubOD,anchor=BOTTOM);

	if (Side == "Nut")
	tube(1.0,od=NutOD,id=43.0,anchor=BOTTOM) // nut side
	position(TOP)
	tube(SpoolSideThick,od=SpoolID,id=NutHubOD,anchor=BOTTOM);

	}



	//———-
	// Build things

	if (Layout == "Show") {
	left(SpoolWidth/2) yrot(90) EryOneCF("Flange");
	right(SpoolWidth/2) yrot(-90) EryOneCF("Nut");
	}

	if (Layout == "Build") {
	left((FlangeOD + Gap)/2) EryOneCF("Flange");
	right((NutOD + Gap)/2) EryOneCF("Nut");
	}

view raw PolyDryer spool washers.scad hosted with ❤ by GitHub

2025-05-21

3D Printed 20×102mm Cartridge

Having accumulated a box of empty 12 gram CO₂ capsules and having already done Too Many bomb fins:

The capsule is obviously the wrong shape, too short, and only 19 mm diameter, but it’s the thought that counts.

Apply the contour gauge to a genuine slightly battered 20×102mm cartridge:

Scan the sketch, import into Inkscape, rotate the image to correct the case taper angle vs. the page, lay lines & curves around the perimeter, align half of it at the page origin to work with OpenSCAD, export as SVG:

Cartridge - 20x102mm outline - Inkscape layout — Cartridge – 20x102mm outline – Inkscape layout

Import into OpenSCAD, let rotate_extrude do the heavy lifting, and remove some pieces:

Cartridge Case - build view solid model — Cartridge Case – build view solid model

The little disk represents a fired primer you’d print separately in a different color and glue into the pocket shown in this cutaway view:

Cartridge Case - cutaway solid model — Cartridge Case – cutaway solid model

The interior void could hold sand for additional heft, as the whole thing is obviously nose-heavy; that’s certainly in the nature of fine tuning. Obviously, we are not dealing with anything that could go bang.

It builds just like you’d expect:

20x102mm cartridge - printing — 20x102mm cartridge – printing

Dab some adhesive on the capsule tip, ditto for the primer, stick them in place, and it’s all good.

I like the gray PETG-CF version:

20x102mm cartridges - blue gray PETG-CF — 20x102mm cartridges – blue gray PETG-CF

Maybe not such a good idea in this day & age. Print responsibly, as they say.

Update

Print a sabot to fit a CO₂ capsule into a genuine steel cartridge.

The solid model:

Cartridge Case - sabot solid model — Cartridge Case – sabot solid model

The OpenSCAD making it happen:

module Sabot() {
tube(SabotOA[LENGTH],id=SabotOA[ID],od=SabotOA[OD],anchor=BOTTOM)
    position(BOTTOM)
      tube(SabotOA[LENGTH]/2,id=SabotOA[ID],od=CartridgeOA[ID],anchor=BOTTOM);
}

The result:

The OpenSCAD source code (minus the sabot) and outline as a GitHub Gist:

Sorry, something went wrong. Reload?

Sorry, we cannot display this file.

Sorry, this file is invalid so it cannot be displayed.

view raw Cartridge – 20x102mm outline.svg hosted with ❤ by GitHub

	// 20x102mm cartridge
	// Ed Nisley – KE4ZNU
	// 2025-05-18

	include <BOSL2/std.scad>

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

	Powder = true; // build internal void

	/* [Hidden] */

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

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

	$fn = NumSides;

	CartridgeOA = [21.0,29.5,101.4]; // must match SVG pretty closely

	PrimerOA = [2.0,8.0,2.0];

	CapsuleTip = [7.5,7.5,5.0];
	Capsule = [7.5,18.8 + HoleWindage,83];
	SeatingDepth = 25.0;

	Void = [CartridgeOA[ID]- 4.0,CartridgeOA[OD]- 4.0,CartridgeOA[LENGTH] – SeatingDepth – 4*PrimerOA[LENGTH]];

	//———-
	// Define shapes

	module Cartridge() {

	difference() {
	rotate_extrude()
	import("Cartridge – 20x102mm outline.svg",layer="Cartridge Aligned Half");
	up(PrimerOA[LENGTH])
	cyl(PrimerOA[LENGTH] + Protrusion,d=PrimerOA[OD],anchor=TOP);
	up(CartridgeOA[LENGTH] + CapsuleTip[LENGTH])
	cyl(SeatingDepth,d=Capsule[OD],anchor=TOP);
	up(CartridgeOA[LENGTH] – SeatingDepth)
	cyl(Void[LENGTH],d=CapsuleTip[OD],anchor=BOTTOM);
	if (Powder) {
	up(Void[LENGTH]/2)
	cyl(Void[LENGTH],d=CapsuleTip[OD],anchor=BOTTOM);
	up(2*PrimerOA[LENGTH])
	cyl(Void[LENGTH],d=Void[OD],rounding=Void[OD]/2,anchor=BOTTOM);
	down(Protrusion)
	cyl(Void[LENGTH],d=PrimerOA[ID],anchor=BOTTOM);
	}
	}

	}

	module Primer() {
	difference() {
	cyl(PrimerOA[LENGTH] – Protrusion,d=PrimerOA[OD] – HoleWindage,anchor=BOTTOM);
	up(PrimerOA[LENGTH])
	spheroid(d=PrimerOA[ID]);
	}
	}


	//———-
	// Build things

	if (Layout == "Show")
	//render()
	difference() {
	Cartridge();
	cuboid(3*CartridgeOA[LENGTH],anchor=LEFT+BACK);
	}

	if (Layout == "Build") {
	Cartridge();
	right(CartridgeOA[OD])
	Primer();
	}

view raw Cartridge 20x102mm.scad hosted with ❤ by GitHub

2025-05-20

Tag: MK4

WS-5000 Anemometer Bird Spike Ring

PolyDryer Internal Fan Puzzle

PolyDryer Humidity vs. Spool Fill

HQ Sixteen: Nose Ring Lights

Sears Humidifier: Lid Hinge Re-repair

3D Printer Filament Spool Washers

3D Printed 20×102mm Cartridge