The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

Tag: Sewing

Fabric arts and machines

Staedtler Mars Masterbow 551 02 WP: Assembly & Tweakage

The corners of Mary’s current quilt project need a 16 inch diameter circle, but my Drawer o’ Drawing Tools that should hold the trammel (distinct from trommel) point & pencil for a steel rule came up empty. While the TEC drawing kit has an extension leg for its compass, IMO it’s entirely too flexy for general use.

Further heap probes produced a Staedtler Mars Masterbow 551 02 WP compass with a robust extension leg:

Staedtler Masterbow – 551 02 WP assembled

It was likely a surplus deal and, to the best of my knowledge, has never been used, so that picture documents how the extension leg fits into the compass. It arrived with the lead in that compass leg, causing some confusion.

The key is to remove the point from that leg, insert the extension leg into the hole, then tighten the screw to clamp the leg in place:

Staedtler Masterbow – leg socket

The collet holding the point was either manufactured incorrectly (which I find hard to believe, because Staedtler in a package embossed “Western Germany”) or suffered damage along the way, as the only point fitting into it stuck out much too far:

Staedtler Masterbow – bow collet wrong point

The small container in the top picture held two spare leads and two other points:

Staedtler Masterbow – point assortment

It turns out the blunt end of the bottom point should fit into the collet, but I had to ream the collet jaws with a (hand-turned in a pin vise) 2.1 mm drill to let that happen:

Staedtler Masterbow – bow collet resized

Then everything lined up correctly and drawing could proceed, although the collet closer doesn’t (seem to) contribute anything to the proceedings.

The thumbscrew adjustment on the compass makes it much more rigid, even with the extension leg sticking out there for an 8 inch span.

I can (now) put the lead in the bow collet and the point in the compass, but IMO it’s easier to hold the compass while drawing around the circle. Your mileage, in the unlikely event you have one of these, may vary.

They definitely don’t make them like that any more …

2026-03-25
Clover Mini-Iron Holder: Revised

The 3D printed Clover Mini-Iron holder served well over the last decade (!), even after one of Mary’s buddies misplaced the iron during a quilting bee:

Clover MCI-900 Mini Iron holder – melted

She asked for a new holder that put the iron at a higher angle for easier gripping, which required only slight tinkering to boot the OpenSCAD code into the current decade:

Clover MCI-900 Mini Iron holder – higher angle

The letters stand one layer proud of the surface just to see what that looked like. I think it’s a nice touch.

The alert reader will note the cord end isn’t quite snugged into its recess. In normal use, the cord hangs over the edge of the sewing table and pulls the iron into place.

I embiggened the base to fit an aluminum plate from the stockpile, because that same cord tends to pull the holder around on the table. The plate puts enough weight on the silicone rubber feet to hold it firmly in place.

A layer of good double-stick tape strips bonds the aluminum plate to the PETG iron holder, after I once again discovered that craft adhesive sheets do not bond to PETG.

2026-03-17

Crosman BB Bottle Cap

Mary made a frame weight to maintain tension on the fabric in the HQ Sixteen longarm:

It’s a sturdy cloth tube filled with BBs, somewhat like a grossly overweight door snake (a.k.a. draft stopper).

The bottle of 6000 copper-plated steel BBs arrived in an overwrap bag of the sort Amazon applies to all bottled products. This was a Good Thing, because the scrap of packing paper did nothing to cushion the bottle in an otherwise empty box. The bag contained most of the shattered cap and a few BBs, with escapees rattling around inside the box and surely a few left along the way.

So I conjured a replacement cap from TPU:

Crosman BB bottle cap - solid model - build view — Crosman BB bottle cap – solid model – build view

It fits around the bottle neck and snaps onto the spout just like the original:

Except this one is unbreakable.

The strapless TPU cap was a quick test to verify the fiddly shoulder snapping onto the bottle snout:

Crosman BB bottle cap - solid model - section view — Crosman BB bottle cap – solid model – section view

As it turned out, we poured all 6000 BBs (minus those few lost-in-transit strays) into the cloth tube, but the bottle will come in handy for something someday.

The OpenSCAD source code as a GitHub Gist:

	// Crosman BB bottle cap
	// Ed Nisley – KE4ZNU
	// 2026-02-22

	include <BOSL2/std.scad>

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

	/* [Hidden] */

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

	HoleWindage = 0.2;
	Protrusion = 0.1;
	NumSides = 634;

	$fn=NumSides;

	WallThick = 1.0;

	Heights = [1.2,2.0,13.0,WallThick]; // for easy tweaking

	Ring = [34.5,39,WallThick];

	Strap = [70.0,5.0,Ring[LENGTH]];

	CapOAL = sum(Heights);

	//—–
	// Conjure it with magic numbers

	module Cap() {

	tube(Heights[0],id=16.8,wall=WallThick+0.6/2,anchor=BOTTOM) position(TOP)
	tube(Heights[1],id=17.4,wall=WallThick,anchor=BOTTOM) position(TOP)
	tube(Heights[2],id1=17.4,id2=14.0,wall=WallThick,anchor=BOTTOM) position(TOP)
	cyl(Heights[3],d=14.0+2*WallThick,rounding2=WallThick/2,anchor=BOTTOM) position(BOTTOM)
	cuboid(Strap,anchor=BOTTOM+LEFT) position(BOTTOM+RIGHT)
	left(1.0)
	tube(Ring[LENGTH],id=Ring[ID],od=Ring[OD],anchor=BOTTOM+LEFT);
	}

	//—–
	// Build things

	if (Layout == "Show") {
	Cap();
	}


	if (Layout == "Section") {
	difference() {
	Cap();
	down(Protrusion)
	cuboid(2*Strap.x,anchor=BOTTOM+LEFT+FRONT);
	}
	}

	if (Layout == "Build") {
	back(Strap.x/2)
	zrot(90)
	up(CapOAL)
	yrot(180)
	Cap();
	}

view raw Crosman BB bottle cap.scad hosted with ❤ by GitHub

2026-02-24

HQ Sixteen: Fabric Rod Bearings

The rods (a.k.a. tubes or poles) holding & guiding the quilt top / batting / backing fabric on Mary’s HQ Sixteen longarm quilting machine span the eleven feet of the table:

HQ Sixteen - table overview — HQ Sixteen – table overview

The two end plates are 1/4 inch steel plate with four punched holes for the rods / tubes, which look remarkably like EMT. The machine is two decades old and Mary is (at least) the third owner, so it’s no surprise the rods long ago wore through the white powder-coat paint on the plates and, during the course of a long quilting project, now deposit black dust on the table.

Black dust not being tolerable near a quilt-in-progress, Mary asked for an improvement.

The tube OD is 28.7 mm (so it’s probably 1 inch EMT) and the plate hole ID is 31.2 mm (likely a scant 1-¼ inch punch), leaving barely a millimeter of clearance all around. I wanted to make a bearing from suitably slippery Delrin / acetal, but figured 3D printed PETG would suffice for at least while.

The proper term is “bushing“, because it has no moving parts:

Rod Bearing Sleeve - solid model - show view — Rod Bearing Sleeve – solid model – show view

On the right side, the bushing rim must fit between the sprockets and the plate:

HQ Sixteen rod - right front — HQ Sixteen rod – right front

The spring-loaded pin holding the tube in place (visible on the inside bottom) sets the maximum length:

HQ Sixteen rod - right outer — HQ Sixteen rod – right outer

The left side has none of that, so I made the bushings a little longer:

HQ Sixteen rod - left inner — HQ Sixteen rod – left inner

The left-side bushings will need a better design should normal back-and-forth sliding push them out of place.

A touch of silicone grease around the plate holes makes those bushings / bearings turn sooo smooth.

The OpenSCAD source code as a GitHub Gist:

	// Bearing sleeve for HQ Sixteen table rods
	// Ed Nisley – KE4ZNU
	// 2026-02-20

	include <BOSL2/std.scad>

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

	/* [Hidden] */

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

	HoleWindage = 0.2;
	Protrusion = 0.1;
	NumSides = 832*4;

	$fn=NumSides;

	Rod = [25.0,28.7,100.0]; // very short rod

	Sleeve = [Rod[OD] + 0.3,31.2 – 0.2,9.0]; // LENGTH = overall
	Rim = [Sleeve[ID],Sleeve[OD] + 6.0,0.6];

	IdlerLength = 15.0;

	NumSlots = 2*4;
	Kerf = 1.0;

	Gap = 5.0;

	module Bearing(oal) {

	difference() {
	union() {
	tube(oal,id=Sleeve[ID],od=Sleeve[OD],anchor=BOTTOM);
	tube(Rim[LENGTH],id=Rim[ID],od=Rim[OD],anchor=BOTTOM);
	}
	for (a=[0:NumSlots-1])
	zrot(a*360/NumSlots)
	up(oal/4 + Rim[LENGTH])
	right(Sleeve[ID]/2)
	cuboid([Sleeve[OD],Kerf,oal],anchor=BOTTOM);
	}

	}


	//—–
	// Build things

	if (Layout == "Show") {
	color("Gray",0.5)
	xcyl(Rod[LENGTH],d=Rod[OD]);
	right(Rod[LENGTH]/3)
	yrot(90)
	Bearing(Sleeve[LENGTH]);
	left(Rod[LENGTH]/3)
	yrot(90)
	Bearing(IdlerLength);
	}

	if (Layout == "Build") {
	right(Rim[OD]/2 + Gap/2)
	Bearing(Sleeve[LENGTH]);
	left(Rim[OD]/2 + Gap/2)
	Bearing(IdlerLength);


	}

view raw Rod Bearing Sleeve.scad hosted with ❤ by GitHub

2026-02-23

Wind Pants Zipper Tab Repair

Unbelievably, the ankle zipper tab broke off in my hand:

Wind Pants Zipper Tab – broken

It’s one of those zippers where the tab releases a lock preventing the zipper from coming unzipped. Mary noped out of removing and replacing the entire zipper.

Trimming a snippet of aluminum miniblind from the Small Box o’ Flat Stuff and two dots of JB Kwikweld epoxy seemed appropriate:

Wind Pants Zipper Tab – clamping

Ugly, but serviceable:

Wind Pants Zipper Tab – repaired

The stray epoxy scraped off under fingernail pressure over the next two days and the pants are ready for the next snowfall.

2025-12-31
USB Charger: Safety FAIL

Mary reported a problem unplugging the USB charger powering the light pad (the successor to the pad I repaired) she uses for quilting layouts:

USB Charger – as found

Yes, that blade is sticking out of the hot (“Line”) side of the outlet.

The only way into the charger was through its other end:

USB charger – interior top

Because I had no intention of returning it to service, I tried pushing the errant blade back in place, only to have it overshoot the mark and bulldoze various parts aside:

USB charger – PCB blade contacts

The two upright shapes contact the blades, but do not lock them in place. The PCB pulled easily out of the case, with no objection from the remaining (“Neutral”) blade.

The blades are simple steel bars press-fit into the plastic case, without holes / dimples / notches to lock them into the plastic. As far as I could tell, they were not molded in place.

I tossed the corpse into the e-waste box, extracted another USB charger from the Box o’ USB Chargers and returned the light pad to service.

I do have a few Genuine UL Listed USB chargers, but these are not among them.

2025-09-25
Sewing Notions Drawer Pull Rethreading

A small sewing notions cabinet, once my mother’s, now holds some of Mary’s supplies and, a few days ago, had one of its drawer pulls fall off. While preemptively tightening all the screws, I found one no longer held onto its pull:

Notions drawer pull – parts

They don’t make drawer pulls like that any more!

As I see things, it can be forgiven for losing its grip after nearly a century.

Thread the screw in as far as it will go and lay the pull flat on the bench vise anvil:

Notions drawer pull – hammering setup

A few gentle whacks with a pin punch on top and bottom, plus a tap on each side, compressed the pull’s remaining threads around & into the screw:

Notions drawer pull – reshaped

Put it back in its drawer, snug the screw, and it’s all good.

That should suffice for at least the remainder of its first century …

2025-07-24