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.
Things around the home & hearth
Some day, when all we know has crumbled to dust, somebody will unearth that plug and wonder “WTF was this all about?” Maybe the pipe and tank nearby will be a hint, but for all I know ABS will outlast even concrete.
This was our last sighting before the earth closed over it…
The new drain field works fine and, even better, it’ll be months before I need even think of mowing the front yard for the first time.
Insert obligatory Ozymandias reference here.
A bit of laparoscopic surgery on the front yard unearthed the drain line from the septic tank to the leach field. Drilling a 1-1/2 inch hole in the top of the pipe revealed that it’s 3/4 full of sludge, which is a Bad Thing: the leach field should get only liquid from the middle of the septic tank.
On the other paw, the house was built a bit over half a century ago and the records that came with it showed the tank was pumped two decades before we arrived. So it goes.
Rather than leave the hole in the pipe open until we get a new drain field, I built a plug that fit the 5 inch OD drain pipe and the 1-1/2 inch drilled hole.
The aluminum build plate produces a smooth surface that’s entirely irrelevant on this part. The ABS film covers the blind hole in the middle that will serve as a drill guide in the unlikely event I must remove the plug.
I’ll admit it looks a bit out of place down there, though. I slobbered urethane adhesive around the central pillar and across the saddle, plugged it in, put a rock on top, and the adhesive foamed into a sludge-tight seal. At least I hope that’s how it worked out; I’m not going to pop it off just to find out.
The solid model looks about like you’d expect:
Never let it be said that a Thing-O-Matic lacks practical applications…
The OpenSCAD source:
// Plug for septic drain field pipe hole
// Ed Nisley - KE4ZNU - Mar 2011
include </home/ed/Thing-O-Matic/lib/MCAD/units.scad>
// Extrusion values
ThreadThickness = 0.33;
ThreadWT = 1.75;
ThreadWidth = ThreadThickness * ThreadWT;
HoleWindage = ThreadWidth; // enlarge hole dia by extrusion width
// Pipe dimensions
PipeOD = 5 * inch; // which is *4* inch cast iron pipe
PipeWall = (3/8) * inch;
PipeID = PipeOD - 2*PipeWall;
PipeLength = 2*PipeOD; // for ease of viewing
HoleDia = (1 + 1/2) * inch; // from a 1-1/2 inch hole saw
PatchOD = 2*HoleDia;
PatchThick = 10.0; // a burly patch for a big old pipe
DrillDia = (1/4) * inch; // pilot hole for removal, just in case
// Convenience settings
Protrusion = 0.1; // extend holes beyond surfaces for visibility
// The central plug
module PlugBody() {
difference() {
cylinder(r=HoleDia/2,h=(PipeOD/2 + PatchThick));
rotate([90,90,0])
cylinder(r=PipeID/2,h=PipeLength,center=true);
}
}
// The shell on the pipe
module PlugShell() {
difference() {
cylinder(r=PatchOD/2,h=(PipeOD/2 + PatchThick));
rotate([90,90,0])
cylinder(r=PipeOD/2,h=PipeLength,center=true);
}
}
// Build it, with rotate/translate to put it flat on its back
rotate([0,180,0])
translate([0,0,-(PipeOD/2 + PatchThick)])
difference() {
union() {
PlugBody();
PlugShell();
}
translate([0,0,PipeOD/2])
cylinder(r=DrillDia/2,h=(PatchThick + Protrusion));
}
The hose on our aging Samsung Quiet Jet (used to be a Quiet Storm, but I suspect they lost a trademark fight) vacuum cleaner has been a constant nuisance. Most recently, the end toward the handle began splitting:
The fix consisted of a tight duct tape wrap, which has absolutely nothing to recommend it other than expediency.
When the same thing happened on the other end, I sealed it up and added a length of husky heatshrink tubing.
The flared end isn’t particularly decorative, but it serves to reduce the strain on the hose. Alas, there’s no practical way to do the same thing on the handle end.
The replacement cost for the hose roughly equals a new vacuum, so when we run out of bags, this one gets harvested for the shop’s Parts Heap.
The X10 RF Remote Control in the kitchen stopped working, which could mean only one thing: a set of dead AAA cells.
A negative terminal in the battery compartment showed the expected corrosion:
The corrosion evidently pushed the cell away from the terminal just enough to starve the remote.
The cells, on the other paw, looked just fine:
They’d been in there a year, sported a date code that’s still a few years in the future, and had a 1.3 V loaded output. Looks like that little bit of corrosion gave me enough of a heads-up to get the cells out before they rotted.
Eks forced me to take a pile of crap useful make-froms, including a gooseneck task lamp that was probably bolted onto a machine tool in its former life. It sported a 20 W halogen bulb, but looked to be just about exactly the right size for those LED floodlights, which is why I didn’t put up much of a fuss about taking it off his hands.
The LED lamps are much bigger than the halogen bulb, but they fit neatly into the housing diameter. All they needed was a bit more front-to-back room, which looked a lot like a chunk of PVC pipe. The housing screws together with a 1.5 mm thread that I can’t produce on my inch lathe; I’m still not set up for thread milling. This being a low-stress application with a lamp that ought to outlast me, I figured I’d just make the belly band slip-fit the two threads, glue it in place, and move on.
I sawed off a length of PVC pipe, faced off the ends in the lathe, then CNC milled a recess to clear the male threads on the gooseneck part (I hate precision boring in the lathe). Given the rather tenuous grasp of that 3-jaw chuck, I made two passes around the perimeter: pipe ID 52.1, thread OD 54.5, remove 1.2 mm all around, about 9 mm down.
On the other end, the female thread ID = 52.2 and the pipe ID = 52.1, so I glued another ring of PVC pipe inside to provide enough meat to turn it down. Once again, saw off a ring, face the ends, then cut out a segment so that the OD circumference of the inner ring is just slightly smaller than the ID circumference of the outer pipe. The result looked like this:
Apply a heat gun to the inner ring until it’s soft enough to stuff into the pipe, clamp it until it hardens, apply PVC cement, and clamp overnight. Contrary to appearances, the ends of the two pipes are flush at the surface. Once again, you cannot have too many clamps:
Turning down the outside to fit the threads shows just how little meat was left on that pipe:
While it was chucked up (and despite my dislike of boring) I bored a bevel to accept the LED lamp and adjusted the OD so the lamp fit snugly between the end of the belly band and the lens holder on the front of the housing:
The switch comes from the Parts Heap. A D drill puts a slightly undersized hole that’s just right for the threaded switch; I simply turned it in by hand. A length of zip cord carries the power up the gooseneck, where various ends get soldered to the switch and lamp.
I applied some hot-melt glue to the threads and pushed everything together:
The glass lens on the front fits in a molded holder with an annular air gap. The LED lamp housing has all those fancy cooling fins against the inner pipe, so there’s a bit of cooling air flow around the lamp and out through the rear black section. A thermocouple reports the lamp temperature gets up around 75 °C in a 14 °C shop; a 50 °C rise might be a tad warm in the summer, but we’ll see what happens.
The power supply came from the Parts Heap: a 12 V 1 A wall switching power supply in the shape of a wall wart. For now, the zip cord from the lamp terminates in a coaxial power jack that (amazingly enough) fits the wart’s connector, but I’ll eventually put a box in there somewhere.
Clamped the butt end of the gooseneck to the backsplash on the countertop under the mill and It Just Works!
I picked up a pair of 12 V 4 W 3-LED floodlights (datasheet, newer datasheet, and catalog) with 34 degree and 24 degree beams from All Electronics, with the intent of making some task lighting fixtures for the shop. Somebody decommissioned the lamps by snipping off a pin, so they’re not immediately useful.
The back pulls off with a bit of difficulty, after removing the two obvious screws and holding the connector body in place while pulling. I didn’t try to remove the circuit board, which would require unsoldering the clearly marked Anode and Cathode LED wires that enter from the bottom of the board.
I plan to build these lamps right into the fixtures, so soldering a wire directly onto the pin makes sense; I expect they’ll outlast my usage and a socket won’t add any value. As an intermediate step, I soldered a short brass tube onto the pin stump:
In new condition, these retail somewhere beyond $60, so cutting 6 mm from one pin shaved about fifty bucks off the price. I suspect they were extracted from somebody’s shiny new, recently abandoned, and probably foreclosed, office complex and were ruined to prevent resale-as-new. The fact that the reflectors got a bit scuffed up along the way wouldn’t help their value any, either.
They draw 330-odd mA from a 12 V supply, run from AC or DC (either polarity), and seem to have a constant-current driver inside. I wouldn’t buy ’em new, but for eight bucks a pop they’re a pretty good deal.
I’m not sure whether all unit prices must be converted to “per 100 count” or not, but it really doesn’t work out well for CFL bulbs (clicky for more dots):
That’s $549.50 per 100 bulbs, if you can’t make it out.
On the shelf below, however, a single-bulb pack priced out to $979 per 100 count, so the 2-pack is definitely a better deal!
The Smell of Molten Projects in the Morning 