Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
It turns out that an ordinary carbide glass drill works just fine on glazed clay pots. Use a low RPM and very slow feed, flood the scene with water, and drill from the other side after the point breaks through.
Glass drill for plant pot hole
The glaze inside the pot already had a flaw that let the water into the clay, from whence it seeped out through the unglazed lower rim. I suppose saturating the clay can’t possibly be good, but I’ve done this to many glazed pots over the years and none of them have ever complained, so it’s all good.
Strictly speaking, I do not have a beard: I simply do not shave (*). There being no money in selling Trimmers for the Non-shaving, a while back I bought a battery operated Beard Trimmer. The NiCd cells lasted for the predictable few years and recently gave up the ghost entirely: an overnight charged produced a weak buzz with no cutting action to speak of.
The case uses one-time snap-together latches, which makes dismantling it a challenge. Start by removing all the gimcrackery on the business end, then pry out the two latches holding the it-was-white-once cutting length adjustment ring. With that out of the way, undo the two latches inside the top and work your way down, prying the case halves apart in the way the overlap flange doesn’t like, so as to force the latches loose.
This picture shows the six latches, three on each side. The ones just to the right of the blue impeller require the most cursing:
Beard trimmer case and innards
The circuit board snaps out, with the two PCB contact areas clamped down by springy contacts leading to the motor.
Beard trimmer – battery charger PCB
The two NiCd cells boast of their High Energy, but they’re only 600 mAh. That’s actually too much for this high-drain, short-run application, as they don’t completely discharge. They’re held in place on the right end with a blob of hot melt glue:
Beard trimmer – NiCd cells
I unsoldered the cells and gave ’em a brute-force overnight charge at C/10 = 60 mA, then ran a discharge test (clicky for more dots):
Beard Trimmer – NiCd Discharge Test
Lookee that! The cells still deliver their rated capacity, even though they no longer worked with the stock charger. I repeated the slow-charge and discharge trick, which produced a perfectly overlapping trace.
Flushed with success, I unleashed the built-in charger overnight, then produced a third overlapping trace.
So they suffered from voltage depression, most likely due to never being completely discharged and then being overcharged far too often. That’s cured by a complete discharge and recharge, which worked perfectly.
I hack back the overgrowth when it gets bushy and recharge the trimmer when it seems to be getting weak, which used to take a week or two. That’s a bad way to maintain a NiCd battery, particularly as the PCB applies a very low load to keep its computronium running, but I have better things to do than babysit a beard trimmer. Honest.
Anyhow, assembly is in the reverse order and it’s perfectly happy again.
I probably won’t change my evil ways, so the next time I’m sure the battery will be really and truly dead.
(*) Not shaving adds about ten minutes a day to my life, which I regard as a fair tradeoff over the course of several decades. It also added a decade to my apparent age, Back In The Day when that mattered. Now it seems to knock off a decade, which isn’t entirely a Bad Thing.
Our Craftsman lawn mower has both a deadman grip for the motor (the Operator Presence Control Bar) and a Drive Control Lever that engages the rear wheel drive. The latter requires a death grip to keep the belt engaged, which means you (well, I) spend about two hours clenching the grip.
Lawn mower – compound leverage handle
I’ve long since flipped the control to the left side and added thick foam padding, but there’s no adjustment that reduces the death-grip requirement: you can change the engagement distance, not the spring constant.
Evidently the Sears engineers have much stronger hands than anyone in our family.
The doodad hose-clamped to the upright part of the mower handle is a basically a hinge that applies force to the tip of the red handle. The hinge axis lies far enough from the handle’s pivot so that holding the hinge against the handle requires very little force; at least it’s no longer a death grip.
Lawn mower – compound leverage handle engaged
It’s not an ideal solution, but it engages and (more importantly) disengages easily. I still don’t like mowing the lawn, but at least I don’t return with a crippled-up hand.
The hinge is actually a lock hasp, so it has a slot that slides neatly over the Drive Control Lever’s tab. I beat both sides into a more-or-less cylindrical form over a piece of pipe, while miraculously not bending the hinge pin.
Evidently the Sears engineers never actually used the damn mower for two hours at a time.
That comment prompted me to rummage around for one of my favorite photos: a much younger version of my Shop Assistant helping us shred leaves in the front yard.
Shop Assistant in Autumn leaf pile
She thinks it’s entirely right & proper to:
don safety goggles while doing anything even remotely eye-unsafe
wear a dust mask to mow the lawn
jam 30 dB foam plugs into her ears during thrash metal concerts
Mary quite deliberately brought home a pair of bedbugs… even knowing what we went through, you cannot imagine how dead those things had to be. She doesn’t just want them dead, she wants them extinct.
Anyhow.
Some pix, atop a scale with 0.5 mm divisions:
They were on loan from Cornell’s Co-op lab, having recently been distinguished from bat bugs.
Part of the spring ritual involves cleaning the maple seeds out of the gutters, which also gives me an opportunity to inspect things up there. This year brought a revolting discovery:
Rotted vent stack gasket
It seems the rubber (?) seals around all three vent stack pipes have disintegrated. Now, the contractor installed these as part of the re-roofing project late in the last millennium, so it’s not like they came with the house. They’re an exact match for what’s currently available at Home Depot and I have no reason to believe new ones will last any longer. Sheesh.
The correct fix involves removing the shingles around the existing aluminum plates, installing new plates, and then replacing the shingles. That seems unwarranted, seeing as how the aluminum remains nicely bonded to everything, so I slipped some solid polyethylene shields around the vent stacks, tucked them under the uphill shingles, and hope that’ll suffice.
The discoloration on the roof is getting worse, except downhill from the chimney’s copper flashing. You can see one of the ugly new black plastic vent seals over on the right:
Copper effect on roof discoloration
I suspect the copper ions kill off the fungus, so, invoking Science, I tucked a foot of copper wire under the ridge vent uphill from a patch of fungus:
Anti-fungal copper wire test
We’ll see if that makes any difference. I suppose the next time I’m up there I should tuck a strip of copper flashing under the shingle on the other side of the chimney to see if a bit more surface area will have more effect.
The switch on that screwdriver failed again, this time by having the internal switch mounting bosses disintegrate:
Cordless screwdriver – broken switch mounts
Not being one to worry about outside appearances, I simply drilled out the bosses to fit a pair of 4-40 screws, put the nuts inside, and it was all good:
Cordless screwdriver – switch with screws
Except that the switch now required an unseemly amount of force to operate in the forward direction. The switch is the cheapest possible collection of bent metal strips and injection molded plastic bits you can imagine, but with some bending and re-staking and general futzing around, it works fine again.
The Smell of Molten Projects in the Morning 