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: Repairs

If it used to work, it can work again

  • Shaft Position Sensor: Trimpot Wrench

    With the shaft position sensor mounted in this position:

    Kenmore 158 Shaft position sensor - overview
    Kenmore 158 Shaft position sensor – overview

    There’s no way to get a screwdriver into the trimpot that adjusts the sensor’s trip point.

    A few minutes with tin snips, nibbling tool, and square file produced a small wrench:

    Trimpot Wrench
    Trimpot Wrench

    One side of the wrench has a 45° bend that made tweaking the pot just slightly easier.

    The proper trip point turned out to be about 90° away from where the trimpot started, with the level midway between the detection points for shiny metal tape and the cutout side of the counterweight.

  • Doorbell Switch Corrosion

    A friend, anticipating a stream of visitors for their freshly hatched baby, asked for help with a defunct remote doorbell. A bit of probing showed that shorting across the pushbutton switch contacts reliably triggered the bell, so I unsoldered it:

    Doorbell switch - intact
    Doorbell switch – intact

    A similar switch from the heap had a longer stem that was easy enough to shorten, so the repair didn’t take very long at all: ya gotta have stuff!

    An autopsy reveals the expected contact corrosion:

    Doorbell switch - parts
    Doorbell switch – parts

    Underexposing the image by about two stops retained some texture on the contact dome.

    The IC date codes suggest the box is over a decade old, which is as much life as one can expect from cheap consumer electronics, particularly with an unsealed switch placed outdoors.

    It’s probably good for another decade…

  • NYS DOT Patch Quality

    After years of neglect, an NYS DOT crew started a really nice repair job on the inside edge of the curve just north of our house. They milled out the deteriorated road surface, cleaned out the debris, and laid in a patch flush with the road surface. That’s quite unlike their usual shovel-some-cold-patch / hand-tamp / drive-over-it process, made familiar everywhere else around here.

    Unfortunately, for unknown reasons, they didn’t fill in the last two feet of the milled-out trench, leaving a tooth-shattering pair of perpendicular edges exactly where you’d least expect them:

    Rt 376 north of Heathbrook - unfinished patch
    Rt 376 north of Heathbrook – unfinished patch

    Ran out of asphalt? Lunch break? Called off to another emergency? We’ll never know.

    I sent a note, with that picture, to the NYS DOT Bicycle & Pedestrian Coordinator, asking what happened; perhaps they planned another layer atop the whole curve to seal the rest of the cracked pavement?

    The next day a crew filled in the hole, which I find far more than coincidental.

    Although it’s better than it was, there’s now a joint that will deteriorate more rapidly than the uniform asphalt layer they should have created.

    We’ll take what we get…

  • If You Can Get To BNC, You Can Get To Anything

    That’s what Mad Phil taught me, back in the day, and it’s still true:

    15 W Dummy Load - Stacked Adapters
    15 W Dummy Load – Stacked Adapters

    From the top:

    • 15 W dummy load with N female
    • N male to BNC female
    • BNC male to UHF female
    • UHF male to UHF male
    • UHF female on homebrew antenna mount

    Obviously, I don’t have enough adapters: I need one with N male to UHF male.

    I actually spent money to get from the reverse-polarity SMA connector on the Wouxun radios directly to UHF female, matching the cable to the antenna mount in one step.

    Sometimes an unsteady ziggurat of adapters isn’t appropriate.

  • FC1002 Frequency Counter Faceplate: BLAM!

    So I picked up the frequency counter and found this:

    FC1002 Frequency Counter - split shattered faceplate
    FC1002 Frequency Counter – split shattered faceplate

    The outer, previously cracked pieces of the faceplate split parallel to the front panel, separating into two layers, and popped free of their mount. The layer closest to the panel remains intact.

    The fragments were flexible and the bottom layer was rigid, suggesting the faceplate consisted of two parts, perhaps an acrylic (?) base with a soft silicone (?) poured atop it for armor and scratch protection.

    It still works fine and the acrylic (?) layer will suffice for my simple needs, despite being slightly marred by the cyanoacrylate glue I slobbered into the cracks.

    I definitely didn’t see that coming…

  • Eroded PTT Cable

    While installing new underseat packs (about which, more later) on my Tour Easy, I discovered a bight of PTT cable had been touching the top of the chain:

    Eroded PTT cable - Tour Easy
    Eroded PTT cable – Tour Easy

    The gentle ripples to the right of the worn-through section seem particularly nice; you couldn’t do that deliberately if you had to.

    This section of cable should have been taped to the upper frame bars. It’s hidden under the seat, just in front of the rear fender, and between the under-seat packs, so it’s basically invisible from any angle.

    Soooo, that probably explains a bit of the intermittent trouble I’d been having with the PTT switch, although most of it came from the corroded switch contacts.

    Rather than replace the whole cable, I cut out the eroded section, spliced the conductors, and taped it firmly back on the tubes.

  • Tour Easy: Push-to-Talk Switch Rework

    The handlebar-mounted PTT button for the amateur radio on my bike once again went toes-up, most like due to the accumlation of road dust and rainwater over the years. Rather than replace the switch, which would require peeling off a massive glob of hot melt glue and resoldering the wires, I just carved the tops off the rivets holding the cover in place, pried off the cover, and removed the button to reveal the top of the switch dome:

    Handlebar PTT switch - corroded dome
    Handlebar PTT switch – corroded dome

    Blech!

    The dome flexes outward to contact the (rather crusty) terminals on either side, so all the action happens under the dome.

    A lineup of the plastic button, the inverted dome, and the cover plate:

    Handlebar PTT switch - components
    Handlebar PTT switch – components

    The top and bottom of the dome show some grit: that’s where it contacted the switch terminals.

    Wiping the crud out of the switch body, scrubulating everything with contact cleaner, and putting it all back together restored the switch to working order. There’s (once again) a snippet of Kapton tape over the cover holding it in place, but I don’t expect this to last very long:

    Handlebar PTT switch - kapton cover
    Handlebar PTT switch – kapton cover

    But it works well enough for now …