Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
An embiggened version of the 8×8 inch fixture, built with MDF for improved durability & flatness:
Layered Paper 8×10in Gluing Fixture – block
That’s an 8×8 quilt pattern as a quick fit check. Should I cut more of those, I’d install rivnuts in the obvious locations:
Layered Paper 8×10in Gluing Fixture – front overview
The white layer is 1 mm thick chipboard with the rivnut heads flush at its surface:
Layered Paper 8×10in Gluing Fixture – front detail
The perspective makes the fit look much worse than it is.
The back side has squishy foam feet keeping the M3 screws off the table:
Layered Paper 8×10in Gluing Fixture – back detail
The large rectangle on the LightBurn tool layer helped align the 8×12 inch MDF stock. The smaller squares show where the 8×8 inch square will fit and confirmed the hole locations:
Gluing Fixture – 200×200-250mm – LightBurn layout
The LightBurn SVG layout is a GitHub Gist, which also includes the template layout for cutting Letter pages to fit the fixture.
The Home Master whole-house water filter setup that Came With The House™ has a sediment filter with a 6 to 12 months lifetime and a “catalytic carbon” filter that need replacing every 95000 gallons. Poughkeepsie City water isn’t particularly challenging and our average use suggests a three-year cycle for the carbon filter, so changing them every 18 months seems reasonable.
The filter headers have fingers to center the cartridges, which works well with the relentlessly cylindrical sediment filter. The header’s outlet orifice produces the indented ring around the central hole:
Sediment water filter – outlet
The water flows downward around the outside of the filter and upward through the central hole.
The carbon filter is about the same diameter, but has a smaller diameter around the outlet that apparently doesn’t engage the centering fingers:
Carbon water filter – off-center outlet
The white crud on the black rubber seal is another example of Nisley’s First Rule of Potable Water Plumbing:
Never ever look inside the pipes supplying your drinking water.
Having seen this happen twice, despite my best efforts to keep the filter housing vertical while tightening its screw threads in the header, I laser-cut four acrylic blocks to hold the filter in the center of the housing:
Carbon water filter – centering blocks
They’re 13 mm wide, 15 mm tall, and 6 mm thick, but the next time around they should be taller to help keep them vertical while sliding them into place.
We’ll know how well they worked in about 18 months.
The Kohler fill valve in the Main Bathroom’s Kohler toilet tank began leaking, but (unsurprisingly) the shutoff valve on its water pipe no longer completely shut off, thus converting a simple replacement into A Plumbing Project. Because toilet shutoff valves sit below all other valves / faucets / plumbing, the pipe can spew a generous amount of water straight up while you’re fumbling with the new valve, no matter how well you (think you) drained the pipes.
So I deployed scrap towels around the pipe, buttered the new valve threads with joint compound, applied various wrenches with appropriate muttering, and swapped the valves without damage to the premises:
Toilet shutoff valve – installed
AFAICT, the chromed pipe and corroded trim plate are original; no possible motivation can convince me to replace that plate. The tattered PTFE tape on the pipe suggests the valve I replaced might have been only a few decades old, albeit with a correspondingly deteriorated washer.
With the water shut off, I replaced the fill valve with a Fluidmaster valve from Box o’ Plumbing Stuff #3; it was new-in-box despite being maybe a decade old. Turned the water back on, fiddled with the float setting to match the Water Line level, and declared victory.
Which lasted until user feedback indicated the new fill valve wasn’t shutting off. After a fruitless day of fiddling about, I replaced the original seal with a repair part taken from Box #3:
Fluidmaster 242 Fill Valve Seal
The fill valve now works perfectly, for reasons having nothing do with the the appearance of either seal, and victory has once again been declared.
The 4-½ inch diameter semicircle is there because the larger half needed a handle for easier maneuvering. As with workshop clamps, quilters can never have enough rulers, so that curve will come in handy for something.
Unfortunately, I did not mirror-image the layout like this:
Semicircular Ruler – LightBurn layout
Which would make it correct when seen through the acrylic:
Semicircular Ruler – engraving
Given the very specific use case, I begged forgiveness and was not compelled to get it right.
Which, as always, required the Greatest Ratchet with a foot of extensions getting the 1-1/16 inch socket down to the rod:
Water Heater Powered Anode – socket wrench
Remember to:
Turn off the water heater power
Shut off the inlet and outlet valves
Open the drain valve to relieve the tank pressure
Only then loosen the anode rod
Seeing the first few inches justified extracting the rod:
Water Heater Powered Anode – old rod top
Due to low overhead clearance and inauspicious pipe locations, I had to hacksaw the bottom third off to extract the rod:
Water Heater Powered Anode – old rod overviewWater Heater Powered Anode – old rod bottom
With the rod out, draining a few gallons of water into a pan didn’t produce any notable gravel, so I didn’t do a complete flush. Much to my delight, the drain has a ball valve!
Given that this is a fancy water heater and I no longer regard anode rod maintenance as a fun-filled activity, I installed a Corro-Protec powered anode rod for cathodic protection without all the crud:
Water Heater Powered Anode – Corro-Protec parts
The wall wart proclaims 15 mA with a green LED indicating it’s hard at work:
Water Heater Powered Anode – Corro-Protec wall wart
The data plate on the back reports 24VDC 15mA, but, being me, I poked at it with a handful of resistors:
Corro-Protec power supply measurements
The electronics could be as simple as a 24 VDC wall wart feeding a 425 Ω series resistor and a transistor switch lighting the LED for currents a little over 6 mA.
A quick ohmmeter check shows the powered rod electrode is open-circuit with respect to the tank, as it should be without much applied voltage. Applying +24 VDC from the wall wart drives 15 mA into the water: the rod is hard at work.
I’ll take a look at it in a year or so just to see what’s going on in there …
Before turning the PVC conduit to the proper diameter for the Shopvac hose adapter, I set up a 20-50-32-80 change gear train for a 100 TPI finish. While the urethane adhesive cured in the hose, I fed the BC gear pair into my change gear generator:
Mini-lathe stacked change gears – 32-50T – solid model
It’s ready for the next time I cut something down to size:
Mini-lathe 100 TPI change gears
One reference suggests a 256 TPI finish for “general turning”, which works out to 20-80-20-80:
Mini-lathe stacked change gears – 20-80T – solid model
That’s just crazy talk, because the BC washer overlaps the D gear teeth:
Mini-lathe 256 TPI change gears
If all else fails and I really need a 256 TPI finish, lathes are pretty good at making washers.
The tapered adapter drags the OpenSCAD code into the BOSL2 era:
Spiral Hose – 1.25in nozzle adapter – solid model
The ID of the hose determined the OD of the lathe-turned PVC tube inside the 3D printed adapter, so a straight pipe would just slide right into both parts.
It would be possible to skip the 3D printing and make the adapter from a single piece of PVC:
Turn one end of the conduit to fit the hose ID
Maneuver the lathe compound to the required 1.05° half-angle
Turn the taper to fit the crevice tool
Clean up the original OD between the two sections
Just turning the whole pipe to a smaller OD and sliding the taper on was definitely easier, particularly given the mini-lathe’s cramped quarters with the compound nearly parallel to the bed.
A generous helping of JB PlasticBonder urethane adhesive bonds the PVC pipe inside the vacuum hose and the tapered adapter.
The as-printed taper perfectly fits the crevice tool shown in the picture and is one wrap of electrical tape smaller than another crevice tool of “the same size”. The Finesse variable handles that situation, should it matter to you.
The OpenSCAD source code:
// Shopvac spiral hose to 1.25 in nozzle
// Ed Nisley - KE4ZNU
// 2026-07-25
include <BOSL2/std.scad>
Finesse = 0.2; // [-0.5:0.1:0.5]
// PVC pipe liner final OD
PipeOD = 28.5;
/* [Hidden] */
NumSides = 4*3*4;
$fn=NumSides;
Protrusion = 0.1; // make holes end cleanly
HoleWindage = 0.2; // make holes large enough to fit
//----------------------
// Dimensions
TAPER_MIN = 0;
TAPER_MAX = 1;
TAPER_LENGTH = 2;
Tool = [30.0,31.1,30.0] + [Finesse,Finesse,0];
FlangeOD = 37.0;
FlangeLength = 5.0;
//render()
difference() {
union() {
cyl(FlangeLength,d=FlangeOD,anchor=BOTTOM) position(TOP)
cyl(Tool[TAPER_LENGTH],d1=Tool[TAPER_MAX],d2=Tool[TAPER_MIN],anchor=BOTTOM);
}
down(Protrusion)
cyl(2*Tool[TAPER_LENGTH] + FlangeLength,d=PipeOD + HoleWindage,anchor=BOTTOM);
}
The Smell of Molten Projects in the Morning 