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.

Category: Oddities

Who’d’a thunk it?

Alligator Clip Lead Refurbishing

So this happened when I grabbed an alligator clip lead:

Dual Alligator Clip Collection

My coax cable and clip lead collection includes everything from “I’ve had it forever” to “Recent cheap crap”, including much of Mad Phil’s collection. Some of the recent crap included Chinese clip leads with what can charitably be described as marginal connections:

Alligator clips – bent wire

The insulation may provide some compliance in the crimp, but the alligator clip itself consists of cheap steel which won’t hold a crimp, even if it was crimped firmly to start with.

As a rule, the crimps aren’t particularly good:

Black Dual Alligator – as manufactured

The most obvious effect is high end-to-end resistance:

Black Dual Alligator – before – A

Yes, yes, 122 Ω in an alligator clip lead is high.

The test setup isn’t particularly intricate:

Black Dual Alligator – test setup

The lackadaisical crimps also have unstable resistances:

Black Dual Alligator – before – B

So I figured I may as well repair the lot of ’em.

I stripped the lead back to expose fresh copper, soldered it to the clip, then re-crimped the clip around the insulation for some token strain relief:

Black Dual Alligator – soldered

I won’t win any soldering awards, but the resistance is way better than before:

Black Dual Alligator – after

If more than half an ohm seems a tad high for a foot of copper wire, you’re right. My slightly magnetized bench screwdriver shows it’s not copper wire:

Copper-plated steel wire

I’d say it’s copper-plated steel, wouldn’t you?

Those of long memory will recall the non-standard ribbon cable I used as a 60 kHz loop antenna. In this case, the Chinese manufacturer figured nobody would notice or, likely, care. Given the crappy overall quality of the end product, it’s a fair assumption.

I was mildly tempted to replace the wire with good silicone-insulated copper, but came to my senses; those “high voltage” silicone test leads will be Good Enough for higher-current connections.

While I was at it, I pulled apart my entire collection just to see what was inside and fix the ailing ones. These clips date back to the dawn of time, with what started as excellent crimps:

Crimped Alligator Clips – as manufactured

Alas, after I-don’t-know-how-many decades, they’re not longer gas-tight, so I soaked a dollop of solder into each one:

Crimped Alligator Clips – soldered – Made In Japan

Chekkitout: “Made In Japan”.

Someone, perhaps me wearing a younger man’s clothes or, less likely, Mad Phil in a hurry, solved a similar problem with bigger blobs and no strain relief:

Crimped Alligator Clips – cut and soldered

So, now I have a slightly better collection of crappy alligator clip leads. The copper-plated steel wires will eventually fail, but it should become obvious when they do.

Test your clip leads today!

2019-08-19
City of Poughkeepsie Police Armor

Returning from a long ride, we spotted an unusual sign at the Vassar Farm entrance (clicky for more dots):

Vassar Farm – Poughkeepsie Police Training sign – 2019-08-12

Even more unusual was the sight of a matte black MRAP jouncing across the field:

Vassar Farm – Poughkeepsie Police MRAP – 2019-08-12

I hadn’t noticed an uptick of the insurgency around here, but I suppose it could happen.

It looks like a Cougar HE 6×6 MRAP on loan from the DLA 1033 Program to the City of Poughkeepsie Police Department. The flat top suggests they dismounted the CROWS gun, which seems a definite step down in no-knock capability.

Some poking around showed the Poughkeepsie Police Department acquired a 107 mm Mortar Carrier some years ago:

Marshall Project – Poughkeepsie 107 mm Mortar Carrier

The M106 is an impressive hunk of tracked armor, although it seems unsuited for urban warfare and would certainly scuff up the streets pretty badly. I don’t know if they scrapped the M106 in favor of the MRAP.

I’m hoping they don’t collaborate with the Dutchess County Sheriff’s Department to patrol the Rail Trail, even within the City limits.

2019-08-17
Monthly Image: A Tree Full of Turtles

Spotted along Robinson Lane:

Tree full of turtles

A closer look at the same number of pixels:

Tree full of turtles – detail

The little one way over on the left is definitely having an adventure!

I’d read of goats climbing trees, but never turtles.

2019-08-15
Mystery Knife / Chisel

I recovered a tool from an intersection during the homeward leg of a bike ride:

Mystery chisel knife – overview

The scabbard is a bit the worse for having been run over by traffic, but the knife is still in good shape.

The back of the blade has been well and truly mushroomed:

Mystery chisel knife – battered back

The blade edge doesn’t have nearly as much damage as you’d (well, I’d) expect from all the hammering on the back and sides:

Mystery chisel knife – blade edge

The molded handle suggests it’s a commercial product, but it has no branding, no maker’s mark, no identification of any kind.

Google Image Search returns useless views of tail lights and rifles. Here, try it for yourself:

Mystery chisel knife

I have no idea what it’s used for.

Do you?

[Update: It’s a Bell System Cable-Sheath Splitting Knife, made by Klein Tools. More details in the comments … ]

2019-08-10
Warm-White LED Strip: FAIL

The roll of warm-white LEDs I used for the first sewing machine lights has evidently aged out:

Failed warm-white LED strip

They’ve been wrapped on their original roll, tucked in an antistatic bag, for the last five years, so it’s not as if they’ve been constantly abused.

All the cool-white LEDs on an adjacent roll in the same bag still work perfectly, so you’re looking at inherent vice.

I harvested the three longest functional sections and dumped the remainder in the electronics recycling box.

COB LEDs provide much more light, if only because they run at higher power densities, and seem to be much better cost-performers:

Juki TL-2010Q COB LED – installed – rear view

Admittedly, I haven’t looked at the RGB LED strips in a while, either.

2019-08-05
Monthly Science: Organ Pipe Mud Dauber Emergence

An industrious pair of Organ Pipe Mud Dauber Wasps assembled their nest last August:

Organ Pipe Mud Dauber Wasp Nest – side view

Their offspring began emerging in early July, with our first picture on 3 July. I’ll leave the image file dates in place so you can reach your own conclusions:

IMG_20190703_184657 – Organ Pipe Mud Dauber Nest – right

We think a titmouse (a known predator) pecked some holes, including the upper hole on the middle tube, as they seemed to expose solid (and presumably inedible) chitin from the outside:

IMG_20190703_184647 – Organ Pipe Mud Dauber Nest – left

More holes appeared in a few days:

IMG_20190709_172632 – Organ Pipe Mud Dauber Nest – right

The irregular spacing along each tube suggests they don’t emerge in the reverse order of installation:

IMG_20190709_172623 – Organ Pipe Mud Dauber Nest – left

Three days later:

IMG_20190712_181634 – Organ Pipe Mud Dauber Nest – right

IMG_20190712_181625 – Organ Pipe Mud Dauber Nest – left

Two weeks after the first holes appeared:

IMG_20190717_172908 – Organ Pipe Mud Dauber Nest – right

IMG_20190717_172922 – Organ Pipe Mud Dauber Nest – left

No more holes have appeared since then, so it seems one young wasp emerges every few days.

This nest produced about a dozen wasps, with perhaps as many launch failures. We’ll (try to) remove it and examine the contents in a few months.

We expect they’ll start building nests all over the house in another month …

Update: Fortunately for us, no nests appeared before the first freeze, so the wasps are holed up elsewhere for the winter.

2019-08-01
Walmart Wiper Selector: FAIL

After five years, I figured it’d be a Good Idea™ to replace the Forester’s wiper blades. Being in the Walmart at the time, I tried to use their helpful Wiper Selector gadget:

Walmart Wiper Selector

You’d think whoever is responsible for updating / replacing such things would have done so several times during the last eight years.

2019-07-28