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: Home Ec

Things around the home & hearth

Satco PAR30 LED Spotlight Teardown

One of those LED spotlights may have barely outlasted its worthless warranty, but not by much, and has been languishing on the back of the bench with “Flickers hot” scrawled on its side.

The metal base didn’t respond to twisting, so I slit the threads with a cutoff wheel:

Satco PAR30 – thread slit

Applying the screwdriver removed the base to reveal a silicone rubber casting:

Satco PAR30 – thread silicone

The small wire emerging near the edge of the plastic case seems to be the neutral contact to the shell, with a poor enough joint to suggest it might have been why the lamp flickered when it got hot.

Some brute force snapped the silicone off at the bottom of the plastic case and broke the two wires bringing AC to the PCB:

Satco PAR30 – thread silicone base

Digging around inside produced a debris field of silicone crumbs, broken resistors, torn caps, and various other components, with zero progress toward removing the shell:

Satco PAR30 – silicone extraction

A little lathe work converted a chunk of PVC pipe into a crude mandrel supporting the mangled case:

Satco PAR30 – base cutting setup

A few millimeters of sissy cuts released a silicone O-ring sealing the shell against the reflector:

Satco PAR30 – O-ring seal

Continuing the cuts eventually revealed the three screws holding the shell to the reflector and the two wires powering the LED:

Satco PAR30 – reflector separated

Chopping off the screws with a diagonal cutter freed the shell and revealed the top of the PCB:

Satco PAR30 – electronics top

It really does have a surprising number of components!

Those three screws connected the LED panel / heatsink to the shell through the back of the double-walled reflector. More brute force peeled the outer shell away and released the panel:

Satco PAR30 – lens assembly

Each of the 5050 packages contains a pair of white LEDs with 5.2 V forward drop for the pair, at the very low test current. They’re all in series, so you’re looking at well over 60 V total forward drop:

Satco PAR30 – LED panel detail

Note that the wiring, which nobody will ever see, follows the electrical color code of white = common and gray = hot.

Perhaps I should turn the lens into an interesting art object …

2021-05-04
Pixel 3a Boot Failure

Attempting to rub a smudge off the phone’s screen while it was booting causes problems:

Pixel 3a boot fail

Rebooting that sucker cleared the problem, so it wasn’t permanently fatal.

Whew!

2021-04-25
Miniblind Mounting Brackets: Version 4

Miniblinds don’t last forever:

Miniblind failure

The plastic frame failed at the pull cord opening, obviously a weak and, alas, non-repairable point.

A quick trip to Lowe’s produced a new miniblind with mounting hardware completely different from the old one. This came as no surprise, as every new miniblind differs from all previous ones; miniblind mounting hardware is not strongly conserved.

The broken frame fit into the plastic end caps mounted just beyond the scarred paint marking the bracket location required for the previous miniblind:

Miniblind bracket – V3

Note that the caps mount with a single screw in the homebrew bracket’s face, which has two holes to match the previous-previous cap.

Also note how the curved moulding strips around the 1955-era windows in this house do not fit any contemporary miniblind hardware, thus requiring Quality Shop Time with every installation.

Although the shiny new hardware had two slots, they neither lined up with the existing bracket holes nor extended quite far enough vertically. I lined things up, marked and drilled a single midline hole in both the new hardware and the old bracket, and reused the old screw and nut:

Miniblind bracket – V4 side

Moving the bracket back to its previous-previous location exposed the scarred paint under the previous position:

Miniblind bracket – V4 front

Fortunately, it’s hidden by the installed miniblind.

That was, all things considered, easy …

2021-04-24
Kenmore Dryer Temperature Selector Puzzle
On rare occasions, our longsuffering and much-repaired Kenmore clothes dryer will sometimes not fully dry a load, as if the heater didn’t turn on. Setting the temperature selector to High:

Kenmore dryer temperature selector – front panel

Then resetting the cycle timer to the spot marked with the otherwise unlabeled asterisk to activate the humidity sensor gets the job done:

Kenmore dryer cycle select dial

We normally crank the knob to the asterisk, leave the temperature set to Normal, and mostly it works.

After perusing the wiring diagram:

Kenmore clothes dryer 110.96282100 – wiring diagram

I thought perhaps the temperature selector had become intermittent, along the lines of the temperature control knob on the oven, so I turned off the breaker, verified the dryer was disconnected, and popped the top:

Kenmore dryer temperature selector – part detail

It turns out that part is no longer available from any of the usual sources; one describes their inventory as both “used” and “out of stock”; if it’s dead, a resurrection will be in order.

The selector knob has three positions:
- Low = 0 Ω, as in a closed switch
- Medium = 5.8 kΩ, most likely a fixed resistor
- High = open circuit, as in an open switch
The Low and High positions meet the limits shown in the diagram and Medium falls in between, so it seems to be working as designed. If it intermittently fails as a short, then the clothes would get Low heat and (I think) would emerge somewhat more dry than we notice.

I put it all back together, but we won’t know for a while if my laying-on-of-hands non-repair had any effect.

One terrifying possibility, which we reject out of hand, is that we occasionally forget to crank the cycle knob around to the asterisk before punching the Start button. That would explain all the observed facts and contradict none, but is inconceivable.
2021-04-11
Bypass Lopper Bumper

I used the long-handled bypass lopper to harvest the 3D printed soaker hose splices and clamps, which made the sad state of the lopper’s bumper painfully obvious:

Bypass Lopper – OEM bumper

Contrary to what you might think, those rivets never had a head on this side and the bumper seems to be held in place by an interference fit with the plastic handle cover.

A bit of cutoff wheel work removed the crimped end on the 5 mm stud holding the bumper to the pot-metal dingus:

Bypass Lopper – shaft cut

Whacking it with a punch separated all the parts:

Bypass Lopper – bumper parts

The gray thing is a silicone rubber vibration isolator that’s a bit too large in all dimensions, but surely Close Enough™ for present purposes.

A length of 5 mm shaft became the new stud, with M3×0.5 threads tapped into both ends and a pair of random screws held in place with red Loctite:

Bypass Lopper – epoxy curing

There are no pix of the drilling and threading, as it was accomplished after a shiny-new 2.7 mm “titanium” metric drill from a not-dirt-cheap set shattered in the shaft:

Shattered metric drill

The blue color on the flutes is Sharpie to remind me it’s defunct. I completed the mission using a #36 drill with no further excitement.

The dingus is now held to the lopper with JB Weld and, should that fail, I’ll drill-n-tap the rivets and be done with it.

2021-04-10
Thermal Laminator Un-jamming

My AmazonBasics laminator wrapped a small card around one of its rollers and jammed solid:

AmazonBasics laminator – interior bottom

The lever sticking out on the lower right (above) drives the rollers in reverse by moving the motor from one gear to the other:

AmazonBasics laminator – roller gears

Obviously, reverse gear wouldn’t get me anywhere, but dismantling the rollers required cutting the junction between the heating elements running through the aluminum extrusions:

AmazonBasics laminator – heater junction

I spliced a few inches of wire onto those leads. If there’s a next time, I can cut the splice in the middle and use a wire nut.

The white plastic curl in the lower right showed they ran a deburring tool around the exit slot and called it Good Enough™.

The gears slide off the roller shafts and the rollers out of the extrusions, after which removing the tightly wrapped and completely useless card posed no problem.

One lone, short, and eagerly self-tapping screw holds each plastic end plate to the extrusion, so be careful about cross-threading.

All in all, this was easy enough, although I’m sure I was supposed to just throw the laminator away and buy a new one.

Update: If you dislodged some of the wires, a few more pix of the interior may come in handy.

2021-03-28
Defensive Driving Course

This year was my turn to take an online Defensive Driving Course to knock a few percent off our automobile insurance premium. It’s admittedly difficult to make traffic law interesting, but this was the worst-written, poorest-edited, and most factually incorrect course I have ever had the misfortune to waste eight hours of my life taking.

For example:

Emergency signals, also called emergency flashers or hazard warning devices, are flashing red lights found on the front and rear of the vehicle

No, they’re amber on both ends of the vehicle. Flashing red on the front is reserved for vehicles with police and firefighters inside.

… material used to block the sun from coming into a vehicle through the windshield and windows must have a luminous transmittance of less than 70%. That means the material must allow at least 30% of the light to pass through it

No, lower transmittance means less light passing through the glass.

I think the author and editors live in a part of the world once colonized by the British Empire:

Driving class – mirror-image roadway crossing

Here in New York State, we drive on the right.

Update: scruss recalls the image in an old UK driving manual. It describes a type of pedestrian crossing unknown in the US.

The sign recognition lesson claimed this sign marks a section of road with two-lane traffic:

Driving class – 2-lane traffic

NYS DMV sa y s it actually indicates two-way traffic on an undivided road.

The course says this sign marks the point where the two-lane section ends:

Driving class – lane reductIon

It really means a divided highway ends and two-way traffic begins.

The course definitely offered amusing incorrect answers:

Driving class – slippery area

The sign really means slippery when wet, but I suppose that’s in the nature of fine tuning.

The closing page of the course told me I could take a survey, but, somehow, the survey never appeared.

2021-03-27