Posts Tagged Repairs
Bathroom Sink Stopper Rod
Posted by Ed in Home Ec, Machine Shop on 2017-10-14
After swapping the corroded steel rod end-for-end twice, I expected this would happen:
Bathroom Sink Stopper Rods
So now we know a chrome-plated steel rod will survive 16 years in a bathroom drain, at least if you’re willing to coddle the fool thing far more than seems reasonable.
I eased a slug of epoxy into the brass tube to seal the wet end. Given how little use the stopper gets, I hope it lasts forever …
SRAM Shift Indicator Repair: Polypropylene Sheet
Posted by Ed in Amateur Radio, Machine Shop, Recumbent Bicycling on 2017-10-13
Over the course of a few weeks, both of the indicators in the SRAM grip shifters on my bike snapped off. Having recently touched my parallel jaw clamp assortment, it occurred to me I could mold snippets of polypropylene sheet (saved from random clamshell packages for just such a purpose) around the nose of a clamp and come out pretty close to the final shape:
SRAM Shift Indicator – shaped replacements
A hot air gun set on LOW and held a foot away softened the polypro enough so a gloved thumb could squash it against the jaw. Too much heat shrinks the sheet into a blob, too little heat lets the sheet spring back to its original shape.
The flat tab of the original indicator is about 1 mm thick. I found a package of 47 mil = 1.2 mm sheet with one nice right-angle bend and ran with it.
Because I expect sunlight will fade any color other than black, that’s the Sharpie I applied.
They don’t look as awful as you might expect. The rear shifter, minus the cover:
SRAM Shift Indicator – rear detail
The front shifter, with cover installed and HT PTT button below the still-good Kapton tape:
SRAM Shift Indicator – front assembled
The transparent covers press the OEM indicators down and do the same for my homebrew tabs. I expect the Sharpie will wear quickly at those contact points; next time, I should tint the other side.
They’re rather subtle, I’ll grant you that.
Now, to see if they survive long enough to make the worry about a brighter color fading away a real problem…
Epson R380 Continuous Ink Supply: Tubing Failure
Posted by Ed in Home Ec, Machine Shop, PC Tweakage on 2017-10-11
After 4.5 years, one of the silicone tubes on the Epson R380’s continuous ink supply system broke:
Epson R380 – broken CISS tube
The yellow smudges in front of the tubing clamp and across the top suggest the total mess lying in wait between the cartridges. Donning my shop apron and wielding damp paper towels cleaned things up well enough.
I cut through all the tubes a few inches back from the clamp, pulled the stubs off the elbow connectors, reinstalled the fresh ends, and re-repaired the clamp with a new cable tie:
Epson R38 – CISS tubes
Although the failing yellow supply surely contributed to the problem, the printhead seems to be on its last legs after nearly nine years. IIRC, I got the printer for $15 after rebate, spent maybe four times that on CISS tanks, and perhaps $200 on good-quality ink in pint bottles, it doesn’t owe me much.
Maybe I shouldn’t buy ink in pint bottles any more.
Glass vs. Epoxy: Divot!
Posted by Ed in Electronics Workbench, Machine Shop, Science on 2017-10-10
The WS2812 RGB LED atop the Bowl of Fire Floodlight …
Reflector floodlight – purple phase
… failed in the usual way after a bit over a year of constant use.
I’d done an unusually good job of epoxying the ersatz heatsink in place:
Reflector floodlight – finned LED holder
I wrapped the bulb in a towel with only the heatsink sticking out, whacked the side of the heatsink parallel to the glass with a plastic-face hammer, and it popped right off:
Epoxy vs glass – divot
The missing piece of the epoxy ring turned out to be a divot ripped out of the glass, which I didn’t notice until I’d chipped the fragment off the aluminum, so no pictures.
Given the relative strengths of epoxy and glass, pulling a divot seems impossible, but folks doing 3D printing on glass platforms have been reporting exactly that failure for years. The prevailing theory seems to involve small scratches and defects in the glass surface, with subsequent weakening, and stresses applied to the epoxy perpendicular to the glass surface pulling the cracks apart.
Replacing the RGB LED will require drilling it out and probably a complete rewiring, because I seem to have made liberal use of epoxy inside the heatsink and brass tube.
Amateur Lock Picking
Posted by Ed in Administrivia, Machine Shop, Oddities on 2017-10-07
For reasons not relevant here, I was called upon to open a bulletin-board lock with a complete lack of keys:
Bulletin Board Lock – locked
It’s obviously not the highest security lock you’ve ever seen. Armed with a small screwdriver and an old darning needle, this took the better part of 30 seconds:
Bulletin Board Lock – opened
Actually, I devoted a few minutes to verify none of my collection of random keys would suffice.
Replacing the lock not being within my remit, I improvised a simple retainer from available materials:
Bulletin Board Lock – improvised strap retainer – front
Yes, the nylon cable tie will surely pull out of the latch:
Bulletin Board Lock – improvised strap retainer
And I admit the installation’s security has taken a definite downward step:
Bulletin Board Lock – push pin security
Some day, I’ll tote a wrench to the site, remove the lock, and improve the improvisation.
Replacing the lock seems mired in an intractable budgetary wrangle. Similar locks being five bucks on Amazon, I’m tempted to just make it happen, but doing so would apparently roil the decision-making stratum. I’m perfectly happy to remain an on-call techie devoid of political ambition.
Cheese Slicer: XTC-3D Epoxy Coating
Posted by Ed in Home Ec, Machine Shop on 2017-10-06
We have, as you might expect, a Favorite Cheese Slicer of no particular provenance. Being made of cheap pot metal, it left black smudges wherever it went and, decades ago, I coated it with bright red rubbery grip material. Recently, the coating became lumpy and peeling off the loose sections revealed a definite problem:
Cheese slicer – aluminum corrosion
Vigorous scrubbing with a foam sanding block and a Scotchbrite pad, interspersed with rotary wire brushing, removed the corrosion and left a slightly pitted metal frame. Protip: scrub under water and wire-brush with a vacuum hose to keep the dust under control.
A pair of 6-32 screws, nuts, and brass sleeves, with two oil dots protecting the frame threads, provided hand grips while I wiped it down with denatured alcohol and coated it with XTC-3D epoxy:
Cheese slicer – epoxy curing
Turns out the mixing stick worked quite well to cover the entire thing, as the epoxy does a great job of leveling itself. I suppose wasting a tiny brush would be more professional, but …
It quietly dripped excess epoxy into a strategically placed trash can for about ten minutes. I wiped off the final drip before the epoxy solidified, leaving a smooth layer over the end of the handle:
Cheese slicer – reassembled
It’s back in service and works as well as ever, with a handle now smooth to the touch. I suppose I could have tinted the epoxy to hide the metal, but we regard those corrosion pits as beausage.
I’ve slathered XTC-3D on some 3D printed parts, but have no idea how durable it is; this should serve as an accelerated survival test under rather harsh usage.
The instruction sheet says XTC-3D isn’t the most transparent epoxy they make and, indeed, the layer left in the mixing pan came out more hazy than I expected:
XTC-3D Epoxy – thin cured layer
They point out the haze doesn’t matter for thin surface coatings, which is certainly true.
Whirlpool Refrigerator Drawer Slide: Another Bracket
Posted by Ed in Home Ec, Machine Shop on 2017-10-05
Thirteen years after the original repair on the left side and eight years after I fixed the drawer slide on the right side, this happened:
Refrigerator shelf slide – failed parts
The general idea is to wrap a new bracket around the old bracket, because trying to remove the old one will probably cause more damage:
Refrigerator shelf slide – trial assembly
A pair of screws hold the new bracket to the shelf support:
Refrigerator shelf slide – support screw nut openings
Those two screws must support the entire weight of the drawer, which is exactly what broke the original all-plastic frame and slide.
The epoxy chip and transparent plastic sheet in the first picture spaced the old aluminum bracket away from the shelf support and reduced the space beyond the new bracket enough to require drilling access holes. Fortunately, they’re hidden inside the support frame, so nobody will ever know.
The shelf support is a huge floppy rectangle, so I clamped it to the bench vise while drilling the holes:
Refrigerator shelf slide – upright vise clamp
The new bracket is on the right, with a sheet of white acrylic spacing it away from the shelf support by exactly the same distance as the angled aluminum snippet replacing the failed epoxy & plastic on the broken part:
Refrigerator shelf slide – bracket parts
The two holes in the middle of the aluminum parts show that I used exactly the same angle brackets as raw material. It’ll be a sad day when I eventually use the last of those brackets.
Putting the parts together, with double-stick tape holding all the parts in place, shows how they fit:
Refrigerator shelf slide – repair trial assembly
And then it just snapped into place. I didn’t bother pretending solvent glue would help anything, nor did I apply any epoxy, so this whole thing hangs from those two 4-40 screws. On the other paw, their steel beats the original white plastic.
I devoutly hope to never rebuild the actual drawer slide, but these dimensions may help somebody else out of a jam:
Refrigerator shelf slide – dimensions
The vertical “40” dimension refers to the available space from the bottom of the white plastic part to the top of the shelf support frame; the new bracket is a tad shorter than that.
The plastic parts in that refrigerator have been a complete disappointment: were it not for my relentless repair jones, we’d likely be on our third or fourth refrigerator by now. Oddly, the cooling parts continue to chug along (*), without more than the occasional loud noise in the middle of the night.
We’re definitely doing our part to reduce our waste stream.
(*) The most recent freezer fan hasn’t failed yet!
Blowback