An outlet thread failed on yet another garden hose Y valve:
Out of an abundance of curiosity, I battered the remaining parts out of the carcass:
One of these days, we must buy an assortment of new fittings …
Tag: Repairs
If it used to work, it can work again
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Another Garden Hose Y Valve Autopsy
Garden Fittings – Failed Y valve – detail Garden Fittings – Failed Y valve – autopsy -
HP 7475A Plotter: Ceramic-Tip Pen EOL
Ceramic-tip plotter pens draw wonderfully crisp lines:
Spirograph pattern – black ceramic pen – detail Eventually, though, the fiber tip wears flush with the ceramic shell, becomes slightly indented, and ceases to make its mark in the world:
HP 7475A Plotter – Ceramic pen – worn tip As the lady says, “Starting from zero, got nothing to lose”, so I applied a fine diamond file around the tip:
HP 7475A Plotter – Ceramic pen – filed tip Well, all I can say is it seemed like a good idea at the time.
Alas, even the newly exposed fiber didn’t make much of a mark on the paper and, as you’d expect, the ragged ceramic tip dragged painfully across the paper. I assume the fiber had filled with fossilized dry ink.
A New Old Stock bag of fiber-tip pens emerged from the Big Box o’ Pens while I was flailing around:
HP 7475A Plotter – NOS Green pen package I think the “812” in the lower right corner is a date code, most likely early in 1988, so the pens started their lifetime countdown at least three decades ago. They still work, though:
HP 7475A Plotter – NOS Green pens The plotter appeared at HV Open’s Mad Science Fair, because everybody loves a plotter!
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Dell UG679 Lithium Battery Teardown
The battery pack on my ancient Dell E1405 laptop finally died, so I tore it apart to see what horrors might lurk within:
Dell UG679 Lithium Battery – teardown The case snaps apart without too much effort, although the delicate single-use latches won’t survive the operation. These certainly didn’t, which didn’t bother me at all, as I already had a replacement battery on order.
One of the cells (in the front) seems to have leaked ever so slightly inside its wrapper:
Dell UG679 Lithium Battery – leaky cell The three cells in that 3P section seem to have failed open: they pass no current at all.
The other pair of 3P slices, charged at 4.2 V with a 700 mA current limit until the current dropped under 10 mA, still have some life:
Dell UG679 3P sections Perhaps recycling individual cells into LED glowies would be nice, as they have enough capacity remaining to run an Arduino for quite a while, and a 1S USB charger would make for a self-contained package.
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Mini-Lathe Cut-Off Tool Holder: Improved Clamp Screw
Apparently all mini-lathe cut–off tool holders suffer from the same problem:
Lathe Cutoff Tool – OEM swaged screw The clamp tightening screw is made from butter-soft Chinese steel with a swaged hex socket. As you’d expect, the hex wrench eventually (as in, after a few dozen adjustments, tops) rips the guts right out of the socket.
The screw has a M6×1.0 mm threads, but the thread around the hex recess is left-handed. While I could, in principle, print a 127 tooth change gear, rebuild the lathe’s banjo to accommodate it, then single-point a backassward M6 thread, it’s easier to just use a standard socket head cap screw:
Lathe Cutoff Tool – rebuilt screw The clamp screw passes through the block at an angle:
Lathe Cutoff Tool – blade view Fortunately, the screw is perpendicular to the angled side over on the left, making it easy to clamp in the Sherline’s vise:
Lathe Cutoff Tool – aligning to screw Using the laser aligner seemed like a good idea at the time, but the top of the screw wasn’t particularly well-centered on the hole’s axis. I couldn’t screw the left-hand part (with the socket) in from the bottom and center the block near its surface, because then I couldn’t extract the screw before proceeding.
I used a diamond burr to grind out a flat for the screw head:
Lathe Cutoff Tool – clearing screw recess The flat came from about twenty manual
G2 I-2.5full-circle passes, stepping down through the hard steel block 0.1 mm per pass, at a too-slow 4000 RPM and a too-fast 30 mm/min feed, with plenty of water squirted from one side into a shop vac snout on the other. The doodle in the background of the first picture shows a first pass at the layout, with the burr centered at X=-2.5; I actually did the grinding from X=+2.5 so most of the passes started in thin air.The screw head started just shy of 10 mm OD and the burr just over 5.2 mm, so the ensuing 5 mm circles created a flat barely large enough. If the flat were perfectly centered on the screw axis, I wouldn’t have had to grind out another millimeter on the left side (toward the bottom of the tool holder body), but it worked out OK:
Lathe Cutoff Tool – 6 mm SHCS test fit The trial fitting also showed the head stuck out ever so slightly beyond the far side of the block, where it would interfere with the blade, so I turned off 0.4 mm off its OD.
If I had a 50 mm SHCS in hand, I’d have used it. Instead, I extended the threads of a 75 mm screw, then lopped off the end to the proper length. I’ll spare you the ordeal, including the moment when I reached for the cutoff tool to shorten the screw. A bag of such screws will arrive shortly, in preparation for future need.
Now the [deleted] cut-off holder works the way it should have from the beginning.
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Mower FOD
For reasons not relevant here, the lawn mower suffered some Foreign Object Damage:
Lawn Mower – bent blade mount I’m sure the hard stop loosened the tolerances along the shaft, but the mower fired right up (with that new blade!) and has no more vibration than usual, despite the seriously bent blade mount.
I no longer have a deep emotional attachment to lawn mowers, which is apparently common, as the label advises me there’s no need to change the oil:
Mower Engine – never change the oil Drive it ’til it drops …
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Houses Are Trouble: Electrical Service Division
The ancient utility pole on the north side of our property fell over a few hours after a thunderstorm rolled through:
Fallen Utility Pole – end view Fortunately, the wire clamps were upward and it just lay there without sparks or excitement. It feeds the vacant house out back, so restoring power wasn’t urgent.
Unfortunately, the lines neatly bisected Mary’s garden:
Fallen Utility Pole – garden view The utility crew arrived a few hours later, disconnected the triplex at the fallen pole, rolled it up, secured it to the source pole out front, and promised a different crew would replace the pole in a while:
Central Hudson truck – 2019-06-27 We agreed restoring service to other folks who needed it should take priority.
Mary’s been ducking the various cable TV / phone / FiOS cables ever since.
The pole has been God’s own toothpick for quite some time, as shown by this picture from 2001:
CHGE pole – rear – top Fortunately for us, its pole tag hadn’t fallen off in all those years:
CHGE Pole Tag – mid-north That little tag may save us ten large during this exquisite little inconvenience …
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Step2 Garden Seat: Replacement Seat
A pair of Step2 rolling garden seats (they have a new version) served in Mary’s gardens long enough to give their seat panels precarious cracks:
Step2 Seat – OEM seat The underside was giving way, too:
Step2 Seat – cracks We agreed the new seat could be much simpler, although it must still hinge upward, so I conjured a pair of hinges from the vasty digital deep:
Rolling Cart Hinges – solid model – bottom The woodpile disgorged a slab of 1/4 inch = 6 mm plywood (used in a defunct project) of just about the right size and we agreed a few holes wouldn’t be a problem for its projected ahem use case:
Step2 Seat – assembled The screw holes on the hinge tops will let me run machine screws all the way through, should that be necessary. So far, a quartet of self-tapping sheet metal (!) screws are holding firm.
Rolling Cart Hinges – solid model – top A closer look at the hinges in real life:
Step2 Seat – top view The solid model now caps the holes; I can drill them out should the need arise.
From the bottom:
Step2 Seat – bottom view Three coats of white exterior paint make it blindingly bright in the sun, although we expect a week or two in the garden will knock the shine right off:
Step2 Seat – painted After the first coat, I conjured a drying rack from a bamboo skewer, a cardboard flap, and some hot-melt glue:
Step2 Seat – drying fixture Three small scars on the seat bottom were deemed acceptable.
The OpenSCAD source code as a GitHub Gist:
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters// Hinge brackets for rolling garden stool // Ed Nisley – KE4ZNU – 2019-06 Layout = "Build"; // [Block,Build,Show] Support = true; /* [Hidden] */ ThreadThick = 0.20; ThreadWidth = 0.40; HoleWindage = 0.2; Protrusion = 0.1; // make holes end cleanly ID = 0; OD = 1; LENGTH = 2; //———————- // Dimensions SeatThick = 6.0; // seat panel above cart body HingePin = [11.5,12.0,7.0]; // ID = tip OD = base HingeOffset = 8.0; // hinge axis above cart body (larger than radius!) HingeBolster = [5.0,24.0,SeatThick]; // backing block below hinge Block = [25.0,HingeOffset + 30.0,23.0]; // Z = above cart body Screw = [3.8,11.0,2.5]; // self-tapping #8 OD=head LENGTH=head thickness ScrewOC = 15.0; // spacing > greater than head OD ScrewOffset = Block.y/2 – (ScrewOC/2 + Screw[OD]/2 + HingeOffset); // space for head behind hinge BlockRadius = 7.0; // corner rounding //———————- // Useful routines module PolyCyl(Dia,Height,ForceSides=0) { // based on nophead's polyholes Sides = (ForceSides != 0) ? ForceSides : (ceil(Dia) + 2); FixDia = Dia / cos(180/Sides); cylinder(r=(FixDia + HoleWindage)/2, h=Height, $fn=Sides); } // Basic block shape // X axis collinear with hinge axes, hinge base at X=0 module HingeBlock() { PinSides = 3*4; PinSupport = [HingePin[LENGTH] – 2*ThreadWidth,0.6*HingeOffset,HingePin[OD]]; // pre-rotated union() { translate([Protrusion,Block.y/2 – HingeOffset,HingeOffset]) rotate([0,-90,0]) rotate(180/PinSides) cylinder(d=HingePin[OD],h=HingePin[LENGTH] + Protrusion,$fn=PinSides); difference() { hull() { translate([Block.x – BlockRadius,-(Block.y/2 – BlockRadius),Block.z – BlockRadius]) rotate(180/PinSides) sphere(r=BlockRadius/cos(180/PinSides),$fn=PinSides); translate([0,-(Block.y/2 – BlockRadius),Block.z – BlockRadius]) rotate([0,90,0]) rotate(180/PinSides) cylinder(r=BlockRadius/cos(180/PinSides),h=Block.x/2,$fn=PinSides); translate([Block.x – BlockRadius,(Block.y/2 – BlockRadius),Block.z – BlockRadius]) sphere(r=BlockRadius/cos(180/PinSides),$fn=PinSides); translate([0,(Block.y/2 – BlockRadius),Block.z – BlockRadius]) rotate([0,90,0]) rotate(180/PinSides) cylinder(r=BlockRadius/cos(180/PinSides),h=Block.x/2,$fn=PinSides); translate([0,-Block.y/2,0]) cube([Block.x,Block.y – HingeOffset,Block.z/2],center=false); translate([0,Block.y/2 – HingeOffset,HingeOffset]) rotate([0,90,0]) rotate(180/PinSides) cylinder(r=HingeOffset/cos(180/PinSides),h=Block.x,$fn=PinSides); } translate([Block.x/2 + HingeBolster.x,0,(SeatThick – Protrusion)/2]) cube([Block.x,2*Block.y,SeatThick + Protrusion],center=true); translate([0,-HingeBolster.y,(SeatThick – Protrusion)/2]) cube([3*Block.x,Block.y,SeatThick + Protrusion],center=true); for (j=[-1,1]) translate([Block.x/2,j*ScrewOC/2 + ScrewOffset,-4*ThreadThick]) rotate(180/8) PolyCyl(Screw[ID],Block.z,8); } } if (Support) { // totally ad-hoc color("Yellow") render(convexity=4) difference() { translate([-(PinSupport.x/2 + 2*ThreadWidth),Block.y/2 – PinSupport.y/2,HingeOffset]) cube(PinSupport,center=true); translate([Protrusion,Block.y/2 – HingeOffset,HingeOffset]) rotate([0,-90,0]) rotate(180/PinSides) cylinder(d=HingePin[OD] + 2*ThreadThick,h=2*HingePin[LENGTH],$fn=PinSides); for (i=[-1:1]) translate([i*4*ThreadWidth – HingePin[LENGTH]/2, Block.y/2 – (PinSupport.y + 1*ThreadThick), HingeOffset]) cube([2*ThreadWidth,2*PinSupport.y,2*PinSupport.z],center=true); } } } module Blocks(Hand = "Left") { if (Hand == "Left") HingeBlock(); else mirror([1,0,0]) HingeBlock(); } //- Build it if (Layout == "Block") HingeBlock(); if (Layout == "Show") { translate([1.5*HingePin[LENGTH],0,0]) Blocks("Left"); translate([-1.5*HingePin[LENGTH],0,0]) Blocks("Right"); } if (Layout == "Build") { translate([0,-Block.z/2,Block.y/2]) rotate([-90,0,0]) { translate([1.5*HingePin[LENGTH],0,0]) Blocks("Left"); translate([-1.5*HingePin[LENGTH],0,0]) Blocks("Right"); } } This original doodle gives the key dimensions, apart from the rounded rear edge required so the seat can pivot vertically upward:
Cart Hinge – dimension doodle The second seat looks just like this one, so life is good …
