Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
The steel lump inside the base is the OEM weight that, in addition to two pounds of transformer, kept the whole affair from toppling over.
The transformer inside the DC supply weighs basically nothing:
LED Desk Lamp – Driver PCB
The original 12 VAC transformer powered a 50 W halogen bulb and loafed along at 14.7 VAC (yes, RMS) into the 4 W LED. The light is somewhat dimmer at 12 VDC, but not enough to worry about.
The Greatest Shopvac emitted an intense smell of electrical death while inhaling fuzzballs from the Basement Shop stairs, prompting me to tear it down. For the record, it’s a Genuine Shop·Vac QSP 10 (Quiet Super Power):
Shopvac QSP – label
Removing the handle and upper plate reveals a slab of (presumably) sound-deadening foam over the motor cooling fan. As far as I can tell, the last job this vacuum had before the previous owner discarded it was inhaling drywall dust without a filter:
Shopvac QSP – upper sound baffle
Flipping the motor assembly over and removing the bottom plate revealed a pair of equally solidified foam slabs baffling the main exhaust path:
Shopvac QSP – sound baffle foam
They eventually became Clean Enough™ after protracted rinsing, so maybe the thing now runs as quietly as the name would lead you to believe, if you believed in names.
Disconnecting and extracting the motor revealed the razor-sharp impeller disk. A shop rag prevents lacerations while torquing off the nut holding it to the shaft:
Shopvac QSP – impeller nut
Rust on the washer below the impeller, along with the layer of caked white cement, suggested water accompanied the drywall dust:
Shopvac QSP – impeller washer
Gentle suasion from the Designated Prydriver eventually eased the washer off the shaft and freed the motor:
Shopvac QSP – motor brush layout
It’s an old-school series-wound brushed universal motor. The plastic plate in the middle of the picture has a helical spring pressing the carbon brush against the commutator:
Shopvac QSP – motor brush detail
The rotor turned … reluctantly with the brushes in place and spun freely without them, suggesting the horrible smell of electrical death came from arcing across the gunk accumulated on the commutator:
Shopvac QSP – commutator as found
Many iterations of diligent scrubbing with denatured alcohol on cotton swabs and old t-shirt snippets got rid of the crud, although that commutator will never look all shiny-clean again:
Shopvac QSP – commutator cleaned
At least the brushes aren’t glued to it!
Reassembly is in reverse order, although I took the liberty of splicing a few inches of wire into the switch leads, because I’m not working under factory conditions with all the proper assembly fixtures:
Shopvac QSP – extended wires
The motor passed the smoke test and no longer smells like death, so it’s at least as good as it ever was.
It may run quieter with clean foam baffles, but I still turn off my power ears or don hearing protection when I fire up any shop vacuum.
The CNC 3018 Z-axis stage has a plastic clamp holding the spindle motor, so I just duplicated the motor diameter in the mounts for my diamond drag bit, cheap pen, and fancy pen holders. For obvious reasons, I tend to err on the small side for anything intended to fit into anything else, which led to each of the holders sporting a small strip of tape to soak up the difference.
While poking around the 3018, I once again noticed the clamp’s crappy fit around the holder:
CNC3018 tool clamp – top
The inside should be circular, but it’s definitely not:
CNC3018 tool clamp – top detail
The end of the 30 mm M3 SHCS bottoms out before the clamp closes, although I’ve managed to crank the screw tight enough to put enough of a dent in there to snug the clamp:
CNC3018 tool clamp – side
Some awkward scraping and filing eroded enough of the plastic to let a 25 mm SHCS close the clamp firmly around the holder:
CNC3018 tool clamp – revised
The tool holders now slide in easily with the screw released and fit firmly with the screw tightened a reasonable amount, minus the tape snippets shimming the difference.
If I had the courage of my convictions, I’d take it all apart, bore the clamp out to a circular profile, realign the clamp screw passage to suit, then rebuild all those tool holders for the new diameter; it now works well enough to tamp that project down.
The blade on one of the Jonas vegetable peelers cracked, which suggests it’s the counterfeit version:
Jonas Peeler – cracked blade
I grooved the metal pin running through the handle:
Jonas Peeler – shaft grooving
A brass tube from the Little Tray o’ Cutoffs and some epoxy should hold things together forevermore:
Jonas Peeler – epoxy
The rainbow colors come from an instantly aborted attempt to silver-solder the parts together. The fact that I even tried a stunt like that shows I’m definitely not the brightest bulb in the chandelier these days.
It turns out the somewhat corroded square shaft is aluminum, neither the cheap steel I expected nor the stainless steel it should be. Perhaps OXO cost-reduced the shaft, discovered aluminum is a poor choice in a saline environment, and changed the packaging to compensate?
Removing / installing the Jesus clip requires careful whacking with a hollow-tip punch against the shaft, with the whole affair laid flat on shop towels, the handle held down to prevent rotation, and the wrap-around body capturing the escaping clip.
Shaft corrosion as of Summer 2020:
OXO Salt Mill – corrosion
Soaking the body in hot water got rid of salt crusts and filled the shell with water. There being no way to completely dry the thing, I parked it in the sun for a day, refilled it, and was unsurprised when the (dried) salt turned into an assortment of moist crystals.
I’ll be talking about e-bikes and the solid modeling required to hang a Bafang motor and battery on your favorite bike for the Poughkeepsie Chapter of the ACM at 1930 EDT this evening:
Bafang Battery Mount – Show view
It’s a Zoom meeting, so (in the unlikely event you have nothing better to do) you could actually “attend”. The ACM meeting description and the Meetup announcement will get you there.
A PDF of the presentation slides (remember slides?) includes copious linkies to sources / blog posts / distractions:
The Smell of Molten Projects in the Morning 