Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
I know it’s still good, because the label has its 4 lb 7 oz refilled gross weight stamped into it, which is exactly what it weighs today.
Walter Smith Welding Supplies may still be in business, perhaps in Poughkeepsie, but their former 18 Downs St location in Kingston has become Noble Gas Solutions:
Noble Gas Solutions – 18 Downs St Kingston – 2019
Back then, you could call Smith Welding at a four digit phone number in Kingston: 5061. Nowadays, you must call Noble Gas with three more digits: 338-5061. As Charles Stross observed, something like 70% of the future is already in place, because infrastructure is so tenacious.
Heck, just look at that Quonset hut!
Keep calm and extinguish on:
Fyre Freez extinguisher – step 4
Two thoughts spring to mind:
Most kitchen fires start waist-high (it’s the late 1950s: where else would she be?)
She’s gonna lose skin on that metal tank
Seems to me a Fyre Freez will get cold enough to freeze skin while discharging, but I admit to not having actually tried it.
Anyhow, given the overall basement decor, the brackets have the right general style:
Fyre Freez extinguisher – bracket detail
Here’s hoping its future will be as dull as its past …
This conversation started during the few hours when I had to turn off my phone’s incoming-call whitelist filter:
Cash Home Sale SMS
Seems to me a cash-for-house buyer who believes anything the seller says about the property is both new to the “real estate” biz and not destined for a long career. Obviously, the whole exchange attempts to increase my engagement and make me agree with everything going on.
Now, should you happen to be moving to the Mid-Hudson Valley and need a really nice shop with an attached house, let me know: we can work out a better deal.
Protip: if you’re in a position to stack seven thousand Benjamins on our kitchen table, don’t get between us and and the horizon.
There is a reason all my calls and texts go through a whitelist filter.
For reasons not relevant here, a new medication has entered the house, accompanied by its Drug Fact Sheet (blurred because you do not have a Need To Know):
Drug Fact Sheet
The background squares are a scant one foot across.
The other side of the sheet is equally dense.
One should review this with each refill to check for new or changed information. Of course, there are no change bars or similar hints.
It might kill ya or cure ya, but you’ll never figure it out from that torrent of verbiage: just like software EULAs, nobody can possibly read and comprehend that stuff.
It’s easy to find the two front screws holding the top in place, although you’ll need either a bendy or offset screwdriver to remove them:
Sears Progressive Vacuum – front case screws
Pull up hard on the cord retraction plunger to remove it, revealing the two rear screws:
Sears Progressive Vacuum – rear case screws
Extract the wires and motor control PCB from their niches:
Sears Progressive Vacuum – motor assembly overview
Prying the latch in the middle of the rear panel (over on the right) releases the motor assembly, which you can then wiggle-n-jiggle upward and out:
Sears Progressive Vacuum – extracting motor assembly
Disconnect the wires, peel off various foam bits, and extract the motor from its carapace. Measure the blower diameter and cut a suitable plywood clamp for the bench vise:
Sears Progressive Vacuum – custom motor clamp
I loves me some good laser cutter action, even when the plywood crate the laser came in doesn’t have much to recommend it:
Sears Progressive Vacuum – failed plywood clamp
I vaguely recall reading the purple tinge comes from the bromine vapor used to dis-insect the wood during manufacturing, before shipping it halfway around the planet.
One area of the commutator looks like it’s in bad shape:
Sears Progressive Vacuum – as-found commutator
Clean the commutator bars in the desperate hope it’s just random crud, even though that seems unlikely, then connect a widowmaker cord to the motor terminals:
Sears Progressive Vacuum – widowmaker line cord
Use a Variac to spin the motor at a (relatively) low speed while watching the brushes and commutator:
Sears Progressive Vacuum – commutator sparking
Now, that is not a nominal outcome.
The cleaned commutator again shows signs of distress:
Sears Progressive Vacuum – scarred commutator
Indeed, measuring the resistance across the line cord terminals shows a shorted winding: 0.0 Ω with the brushes aligned on the bars just antispinward of the scars.
So the motor is definitely, irretrievably dead.
Extracting the brushes shows the arcs have eroded their spinward edges:
Sears Progressive Vacuum – eroded motor brushes
The dark smudge on the windings seems due to internal problems, rather than just the arcs, because the wiring crossing between the commutator and the smudge remains clean:
Sears Progressive Vacuum – charred motor windings
One can buy a used motor assembly on eBay for about $40, with no assurance it doesn’t also have a shorted winding.
Burn some holes and draw lines 10 mm in from the physical corners, like this:
LB Camera Cal – corner target
Burn holes and lay in a 10 mm grid at the center point:
LB Camera Cal – center grid
The center grid as seen through the camera:
LB Camera Cal – center grid overlay
That’s after adjusting the X and Y offset to align the center of the imaged grid with the center of the design grid. That’s using the non-faded image to make the target lines more visible.
The corner markers don’t quite line up with the grid, but they’re not off by much (using the faded image to make the grid more visible):
You could, of course, split the difference among all five sites, but I think having the middle of the platform be more accurate than the far corners makes more sense.
Early on, I stuck a camera to the lid of my OMTech 60 W laser:
OMTech Laser – camera mount
The uncorrected view from the camera (through VLC):
LB Uncorrected Camera View
After calibration and alignment, LightBurn underlays this view of the platform behind the workspace:
LB Corrected Camera View
The correction depends critically on the camera maintaining its position / orientation / focus, which turns out to be a bad assumption for the camera I’ve been using, because the (metal) focus locking screw binds directly on the (metal) lens threads. This works, until vibrations slightly loosen the screw and the lens shifts ever so slightly.
After noticing the focus had shifted again, I tucked a snippet of silicone insulation from some 30 AWG hookup wire into the screw hole to compress against the lens thread, then re-did the entire sequence with some attention to detail.
Pulsing the laser in each corner produced pinholes exactly 700×500 mm apart. One diagonal is 859.0 mm and the other is 861.5 mm, pretty close to the ideal 860.2 mm.
Next, to measure the offsets from some known positions …
Mary left the sticky card traps in the onion patch until the last onions came out, clustered them around the leeks, and collected them long after the season was over.
I count maybe twenty flies that might be onion maggot flies or cabbage maggot flies.
The cards protected the onion crop, failed miserably for the leeks, and did nothing for the nearby cabbages. Deploying the cards while planting worked very well, refreshing them after a month continued the protection, but the main fly season seems to end shortly thereafter.
All the sticky cards as a slideshow, starting with the three along the border fence:
VCCG Onion Card – fence A – 2022-11
VCCG Onion Card – fence B – 2022-11
VCCG Onion Card – fence C – 2022-11
VCCG Onion Card – plot A – 2022-11
VCCG Onion Card – plot B – 2022-11
VCCG Onion Card – plot C – 2022-11
VCCG Onion Card – plot D – 2022-11
The cards remain sticky to my fingers, but an adroit fly could skate over the debris field and emerge unscathed.
The Smell of Molten Projects in the Morning 