Tag: Repairs

If it used to work, it can work again

Monitor Arm Tilt Adjustment: Bad Part Repair

The tilt (it’s really “pitch”, but I can’t make a case for being that pedantic) adjustment on a recently arrived monitor stand / arm was nonfunctional, because the metal clamp had been bent about a millimeter too narrow to fit the plastic core. This is how it should look:

Monitor tilt adjustment – installed

As delivered, the plastic core was 32-ish mm wide and the gap at the base of the metal clamp was 31 mm, so the clamp arms stuck out at an angle on both ends of the core .

Because the cap screw bottomed out on the threads in the far side of the clamp, it couldn’t be tightened enough to force the clamp arms against the core.

Well, if the core is a millimeter too large for the clamp, shortening it should solve the problem; I can always shorten the screw if it comes to that.

Quick! To the mini-lathe:

Monitor tilt adjustment – lathe setup

Shaving half a millimeter from each side:

Monitor tilt adjustment – shaved

Twirling a deburring bit in each hole got rid of the swarf.

Rather than trimming the cap screw, a pair of fender washers keep it from bottoming out. With the core fitting into the clamp, the arms grip the core firmly on both sides with plenty of friction:

Monitor tilt adjustment – tweaked

I’ve bought this brand of arm before and the most recent pair have definitely been cheapnified from earlier ones. Because only one had a bad tilt clamp, the OEM may be in the middle of a changeover and shipped it with mismatched parts.

I wonder how many stands / arms get returned because they just don’t work?

2026-03-13
LED Garage Light: Autopsy

The hidden part of all three LED arrays in the dead garage light looked like this:

LED Garage Light – inadequate heatsink compound

Although the compound was still gooey, there wasn’t nearly enough of it. The few tendrils on the heatsink suggest the LED array had bowed upward, pulled away from the cast aluminum, and eliminated any direct conduction.

A bit of probing showed each LED array had 16 series groups of 4 parallel LEDS, with one group in each array failed open. That group was toward the end away from the inadequate heatsink compound: the LEDs died from heatstroke brought on by neglect.

The Drawer o’ LED Arrays disgorged a bag of surplus LEDs labeled “10 W 9-12 V 750 mA”:

LED Garage Light – epoxy replacement

It’s sitting on a generous blob of steel-filled JB Kwik epoxy that should do a great job of conducting heat. A bag of cheap constant-current supplies is on order.

Amazon has similar “10 W 9-12 V 350-450 mA” arrays.

Try as I might, I can’t get 10 W from those numbers, but I’ve never understood advertising math.

2026-03-10
Unbending Furnace Zone Drain Valve Knobs

For reasons long lost in our house’s history, two of the zone drain valves on the furnace apparently had something heavy fall on them from a great height:

Furnace zone drain valve – bashed knob

I was certain those knobs were made of brittle pot metal and would snap when I tried to un-bend them.

My weight bench being next to the furnace, I had plenty of opportunities to contemplate conjuring a 3D printed knob similar to the dumbbell nuts, but with the undamaged central part of the metal knob engaging the valve stem to avoid thermoplastic shapes around hot metal.

One can, of course, buy replacement knobs, but where’s the fun in that?

Expecting to cut most of the knob away, I applied needle-nose pliers to the rim and, mirabile dictu, not only did it not immediately snap, I managed to un-bend it into a reasonable facsimile of its original shape.

It wasn’t just beginner’s luck, because I did it again:

Furnace zone drain valve – unbent knobs

Both of those knobs have obvious fractures and aren’t the prettiest things you’ll ever see, but they don’t get a lot of use. I can say, without fear of contradiction, they’re in fine shape.

However, I’m certain those valves will need new washers if I ever turn those knobs …

2026-03-04
MTD Snowblower Muffler Bolt Bracket: Redux

Nearly eight years ago I replaced the OEM bracket locking the two long bolts on the MTD snowblower’s muffler to prevent them from loosening from vibration:

Snowblower muffler installed

Well, it happened again, with the top bolt working its way out, so those little crimps weren’t enough. As before, I watched it happen and saw the bolt fall sizzling into the snow.

Verily it is written: When brute force isn’t working, you’re not using enough of it:

MTD Snowblower muffler

I renewed the Never-Seez on both bolts and, for good measure, dabbed some on the third bolt securing the muffler bracket atop the engine block.

That machine really vibrates!

2026-03-02
Blackout

Some weeks ago Mary heard a loud bang just as the lights went out. Central Hudson crews arrived shortly thereafter and began examining the transformer serving the group of houses around us. I wandered over to ask questions and learned the bang came from a high-voltage fuse atop a pole 800 feet from our house.

With all the power cables underground, the crews were locating the transformer just upstream of the problem, with the intent of disconnecting it and restoring power to everybody else. That took a few hours for our service, but folks up the hill remained in the dark maybe six more hours.

The paint on the transformer enclosures has been weathering for many decades, but I spotted this one up the hill that looks different from all the rest:

Scorched utility transformer housing

The scorched half of the enclosure pivots upward to reveal the high-voltage disconnect switch, fuses, and low-voltage connections. This one is across the street from our house:

Neighborhood distribution transformer

I think something went badly wrong in there and the transformer overheated to the point of insulation failure, whereupon the short circuit blew the HV fuse half a mile away down the hill.

I hope it’s not the beginning of a trend …

2026-02-25

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

Snowplow vs. Streetlight

Spotted on one of our regular walks up the hill:

Damaged pole – snow tracks

Vassar College sent a plow along the walking path linking the campus with the faculty enclave on Old Silvermine Place, but the clearance between the lamp pole and the boulder blocking the entrance wasn’t quite adequate.

Some days later, the light fixture was missing and the power cable sported three cheerful wire nuts:

Damaged pole – wire nuts

Another pole has been lying flat on the ground for (at least) the last two years and I’ve always wondered if its wires (within easy reach) were live under their nuts. Knowing the lamp power is 277 VAC from a 480 VAC three-phase service, I’m disinclined to find out.

Yes, I notice such things.

2026-02-16