Tag: Repairs

If it used to work, it can work again

Bird Feeder Unbending

At some point in its history, the left rail holding the wood perch on our industrial-strength “squirrel proof” seed feeder took a hit, most likely from being dropped:

Squirrel on bird feeder

I finally got a Round Tuit and un-bent the poor thing:

Bird feeder – rail un-bending

Because the bend happened at the base of the vertical strut holding the shutter, I clamped a Genuine Vise-Grip sheet metal pliers along the straight section. The Craftsman knock-off Vise-Grip then applied torque at the bend, rather than just making things worse, and some two-axis tweakage lined up the rail pretty well.

With the bend taken care of, I clamped the rail in the bench vise with some scrap wood around the strut:

Bird feeder – warped rail

A percussive adjustment jam session flattened the top flange, leaving both sections as flat as they’re gonna get.

While I was at it, I turned a pair of stepped aluminum washers for the new wood rod:

Bird feeder – parting off washer

Which looked about like you’d expect, including a little chatter from the cut off tool:

Bird feeder – perch hardware

Yeah, I drilled the wood rod on the lathe, too; I loves me some simple lathe action.

Reassemble in reverse order and it’s all good:

Bird feeder – perch installed

We’re supposed to bleach the feeder every week to kill off the bacteria causing House Finch Eye Disease and, while I can’t promise a weekly schedule, we’ll (try to) reduce the amount of crud on the feeder this year.

If you’ve got a feeder, sign up for Project Feederwatch and do some citizen science!

2018-11-13
SRAM X.9 Grip Shift Guts

The guts of the failed SRAM X.9 rear shifter from my Tour Easy:

SRAM X.9 grip shifter – innards

The identical rear shifter on Mary’s bike also seems to be wearing out, as it glides between two of her favorite click stops a bit too easily. You can see the spring peeking out to the right, beyond the white tube, and the notches forming the clicks.

AFAICT, the raised section between the notches is wearing down; there’s no repair for that sort of thing. I took this one apart to see what’s inside: now we know!

We’ve agreed to not replace the shifter until the situation gets worse. An X.0 shifter should arrive shortly; it appears identical except for deeper scallops around the grip.

2018-11-11

Kenmore Progressive Vacuum Tool Adapters: Third Failure

The adapter for an old Electrolux crevice tool (not the dust brush) snapped at the usual stress concentration after about three years:

Crevice tool adapter - broken vs PVC pipe — Crevice tool adapter – broken vs PVC pipe

The lower adapter is the new version, made from a length of 1 inch PVC pipe (that’s the ID, kinda-sorta) epoxied into a revised Kenmore adapter fitting.

The original OpenSCAD model provided the taper dimensions:

Electrolux Crevice Tool Adapter - PVC taper doodles — Electrolux Crevice Tool Adapter – PVC taper doodles

The taper isn’t quite as critical as it seems, because the crevice tool is an ancient molded plastic part, but a smidge over half a degree seemed like a good target.

Start by boring out the pipe ID until it’s Big Enough (or, equally, the walls aren’t Scary Thin) at 28 mm:

Crevice tool adapter - boring PVC — Crevice tool adapter – boring PVC

Alas, the mini-lathe’s craptastic compound has 2° graduations:

So I set the angle using a somewhat less craptastic protractor and angle gauge:

Crevice tool adapter - compound angle — Crevice tool adapter – compound angle

The little wedge of daylight near the gauge pivot is the difference between the normal perpendicular-to-the-spindle axis setting and half-a-degree-ish.

Turning PVC produces remarkably tenacious swarf:

Crevice tool adapter - PVC swarf — Crevice tool adapter – PVC swarf

The gash along the top comes from a utility knife; just pulling the swarf off didn’t work well at all.

The column of figures down the right side of the doodles shows successive approximations to the target angle, mostly achieved by percussive adjustment, eventually converging to about the right taper with the proper dimensions.

Cutting off the finished product with the (newly angled) cutoff bit:

Crevice tool adapter - cutoff — Crevice tool adapter – cutoff

And then It Just Worked™.

The OpenSCAD source code for all the adapters as a GitHub Gist:

	// Kenmore vacuum cleaner nozzle adapters
	// Ed Nisley KE4ZNU November 2015 and ongoing

	// Layout options

	Layout = "CrevicePipe"; // MaleFitting CoilWand FloorBrush
	// CreviceTool Crevice Pipe ScrubbyTool LuxBrush DustBrush

	//- Extrusion parameters must match reality!
	// Print with +1 shells and 3 solid layers

	ThreadThick = 0.25;
	ThreadWidth = 0.40;

	HoleWindage = 0.2;

	function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit);

	Protrusion = 0.1; // make holes end cleanly

	//———————-
	// Dimensions

	ID1 = 0; // for tapered tubes
	ID2 = 1;
	OD1 = 2;
	OD2 = 3;
	LENGTH = 4;

	OEMTube = [35.0,35.0,41.7,40.5,30.0]; // main fitting tube
	EndStop = [OEMTube[ID1],OEMTube[ID2],47.5,47.5,6.5]; // flange at end of main tube

	FittingOAL = OEMTube[LENGTH] + EndStop[LENGTH];

	$fn = 12*4;

	//———————-
	// 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);
	}


	//——————-
	// Male fitting on end of Kenmore tools
	// This slides into the end of the handle or wand and latches firmly in place

	module MaleFitting() {

	Latch = [40,11.5,5.0]; // rectangle latch opening
	EntryAngle = 45; // latch entry ramp
	EntrySides = 16;
	EntryHeight = 15.0; // lower edge on inside of fitting

	KeyRadius = 1.0;

	translate([0,0,6.5])
	difference() {
	union() {
	cylinder(d1=OEMTube[OD1],d2=OEMTube[OD2],h=OEMTube[LENGTH]); // main tube

	hull() // insertion guide
	for (i=[-(6.0/2 – KeyRadius),(6.0/2 – KeyRadius)],
	j=[-(28.0/2 – KeyRadius),(28.0/2 – KeyRadius)],
	k=[-(26.0/2 – KeyRadius),(26.0/2 – KeyRadius)])
	translate([(i – (OEMTube[ID1]/2 + OEMTube[OD1]/2)/2 + 6.0/2),j,(k + 26.0/2 – 1.0)])
	sphere(r=KeyRadius,$fn=8);

	translate([0,0,-EndStop[LENGTH]]) // wand tube butts against this
	cylinder(d=EndStop[OD1],h=EndStop[LENGTH] + Protrusion);
	}

	translate([0,0,-OEMTube[LENGTH]]) // main bore
	cylinder(d=OEMTube[ID1],h=2OEMTube[LENGTH] + 2Protrusion);

	translate([0,-11.5/2,23.0 – 5.0]) // latch opening
	cube(Latch);

	translate([OEMTube[ID1]/2 + EntryHeight/tan(90-EntryAngle),0,0]) // latch ramp
	translate([(Latch[1]/cos(180/EntrySides))cos(EntryAngle)/2,0,(Latch[1]/cos(180/EntrySides))sin(EntryAngle)/2])
	rotate([0,-EntryAngle,0])
	intersection() {
	rotate(180/EntrySides)
	PolyCyl(Latch[1],Latch[0],EntrySides);
	translate([-(2*Latch[0])/2,0,-Protrusion])
	cube(2*Latch[0],center=true);
	}
	}
	}

	//——————-
	// Refrigerator evaporator coil wand

	module CoilWand() {

	union() {
	translate([0,0,50.0])
	rotate([180,0,0])
	difference() {
	cylinder(d1=EndStop[OD1],d2=42.0,h=50.0);
	translate([0,0,-Protrusion])
	cylinder(d1=35.0,d2=35.8,h=100);
	}
	translate([0,0,50.0 – Protrusion])
	MaleFitting();
	}
	}


	//——————-
	// Samsung floor brush

	module FloorBrush() {

	union() {
	translate([0,0,60.0])
	rotate([180,0,0])
	difference() {
	union() {
	cylinder(d1=EndStop[OD1],d2=32.4,h=10.0);
	translate([0,0,10.0 – Protrusion])
	cylinder(d1=32.4,d2=30.7,h=50.0 + Protrusion);
	}
	translate([0,0,-Protrusion])
	cylinder(d1=28.0,d2=24.0,h=100);
	}
	translate([0,0,60.0 – Protrusion])
	MaleFitting();
	}
	}

	//——————-
	// Crevice tool

	module CreviceTool() {

	union() {
	translate([0,0,60.0])
	rotate([180,0,0])
	difference() {
	union() {
	cylinder(d1=EndStop[OD1],d2=32.0,h=10.0);
	translate([0,0,10.0 – Protrusion])
	cylinder(d1=32.0,d2=30.4,h=50.0 + Protrusion);
	}
	translate([0,0,-Protrusion])
	cylinder(d1=28.0,d2=24.0,h=100);
	}
	translate([0,0,60.0 – Protrusion])
	MaleFitting();
	}
	}


	//——————-
	// Crevice tool
	// Hacked for 1 inch Schedule 40 PVC pipe stiffening tube

	module CrevicePipe() {

	PipeOD = 33.5;

	union() {
	translate([0,0,10.0])
	rotate([180,0,0])
	difference() {
	cylinder(d1=EndStop[OD1],d2=PipeOD+28ThreadWidth,h=10.0);
	translate([0,0,-Protrusion])
	cylinder(d=PipeOD,h=100);
	}
	translate([0,0,10.0])
	MaleFitting();
	}
	}


	//——————-
	// Mystery brush

	module ScrubbyTool() {

	union() {
	translate([0,0,60.0])
	rotate([180,0,0])
	difference() {
	union() {
	cylinder(d1=EndStop[OD1],d2=31.8,h=10.0);
	translate([0,0,10.0 – Protrusion])
	cylinder(d1=31.8,d2=31.0,h=50.0 + Protrusion);
	}
	translate([0,0,-Protrusion])
	cylinder(d1=26.0,d2=24.0,h=100);
	}
	translate([0,0,60.0 – Protrusion])
	MaleFitting();
	}
	}

	//——————-
	// eBay horsehair dusting brush
	// Hacked for 3/4" Schedule 40 PVC stiffening tube
	// eBay: 30.0 32.0 30.0
	// Shopvac: 30.3 31.0 25.0
	// Must build snout down with brim to avoid support

	module DustBrush() {

	PipeOD = 27.0; // stiffening pipe
	Snout = [0,0, 31.0, 30.3, 25.0];
	TaperLength = 10.0; // transition cone from fitting to snout

	union() {
	translate([0,0,Snout[LENGTH] + TaperLength])
	rotate([180,0,0])
	difference() {
	union() {
	cylinder(d1=EndStop[OD1],d2=Snout[OD1],h=TaperLength);
	translate([0,0,TaperLength – Protrusion])
	cylinder(d1=Snout[OD1],d2=Snout[OD2],h=Snout[LENGTH] + Protrusion);
	}
	translate([0,0,-Protrusion]) // 3/4 inch Sch 40 PVC
	PolyCyl(PipeOD,100);
	}
	translate([0,0,Snout[LENGTH] + TaperLength – Protrusion])
	MaleFitting();
	}
	}


	//——————-
	// Electrolux brush ball

	module LuxBrush() {

	union() {
	translate([0,0,30.0])
	rotate([180,0,0])
	difference() {
	union() {
	cylinder(d1=EndStop[OD1],d2=30.8,h=10.0);
	translate([0,0,10.0 – Protrusion])
	cylinder(d1=30.8,d2=30.0,h=20.0 + Protrusion);
	}
	translate([0,0,-Protrusion])
	cylinder(d1=25.0,d2=23.0,h=30 + 2*Protrusion);
	}
	translate([0,0,30.0 – Protrusion])
	MaleFitting();
	}
	}



	//———————-
	// Build it!

	if (Layout == "MaleFitting")
	MaleFitting();

	if (Layout == "CoilWand")
	CoilWand();

	if (Layout == "FloorBrush")
	FloorBrush();

	if (Layout == "CreviceTool")
	CreviceTool();

	if (Layout == "CrevicePipe")
	CrevicePipe();

	if (Layout == "DustBrush")
	DustBrush();

	if (Layout == "ScrubbyTool")
	ScrubbyTool();

	if (Layout == "LuxBrush")
	LuxBrush();

view raw Kenmore Wand Bushings.scad hosted with ❤ by GitHub

2018-11-08

Un-bending a Machinist’s Parallel Clamp Jaw

A previous owner used a little too much force on this machinist’s parallel clamp:

Bent parallel clamp jaw

It’s been in the bottom of my clamp box forever, so I figured I should either fix it or toss it. Grabbing the butt end in the bench vise and applying some percussive adjustment with a 3 pound hammer straightened it right out:

Parallel clamps in action

Done!

2018-11-07
Cheese Slicer Rebuild

The cheese slicer frame looked much better after sandblasting with 220 aluminum oxide grit:

Cheese slicer – sandblasted

The flower bed outside the Basement Laboratory door seems a bit dusty, though.

Slathering it with JB Weld steel-filled epoxy went reasonably well:

Cheese slicer – JB Weld curing

JB Weld is much much more viscous than the clear XTC-3D I used last year and the final coating, while smoother than what you see here, has too many sags and dents to say “good job”. I didn’t bother coating the upper tips, because the epoxy will wear off from my morning KP.

The aluminum roller turned on those bare stainless steel screws in the tray, with the threads chewing into the roller bore. While the epoxy was curing, I drilled out the roller to remove most of the ridges:

Cheese slicer – drilling roller

Cut a pair of stainless screws slightly longer than the old screws, then turn the threads off to make a shaft:

Cheese slicer – screw reshaping

The lathe spindle runs in reverse, so the cutting force tends to tighten the screw in the nuts. The big old South Bend lathe had a screw-on chuck and didn’t really like turning backwards.

The new screws won’t win any beauty prizes, but they get the job done:

Cheese slicer – screw shafts

Turn a Delrin rod to a press fit in the drilled-out roller:

Cheese slicer – turning Delrin bearing

Part it off, repeat, ram them into the roller, then drill to a loose fit around the smooth-ish screw shafts:

Cheese slicer – drilling Delrin bearing

Reassemble in reverse order:

Cheese slicer – rebuilt

Looks downright industrial, it does.

Stipulated: this makes no economic sense, absent the simple fact we appreciate utensils that just work.

2018-11-05
Badger Propel Air Fittings: DIY Cork Washers

The tiny sandblaster turns out to be a Badger 260 with miniature Propel threaded fittings on the air line:

Badger Propel air fitting – DIY cork washers

Foreseeing a Propel washer getting lost in the confusion, I punched a few from a cork sheet and trimmed them to half-thickness. The little brass hole punch isn’t good for more than a few whacks, but that’s all I needed. My cork is crumblier than theirs, but I got a few decent-looking washers and, with a bit of luck, won’t need any of them.

Maybe I should make a soft gasket from a thin plastic sheet?

2018-11-02
Monthly Science: End of the Cheese Slicer Epoxy Coating

The corrosion growing on our long-suffering cheese slicer finally ruptured its epoxy coating:

Cheese Slicer – epoxy coating split

Most of the epoxy remains in good shape, but it’s obviously not the right hammer for this job.

Having recently spotted my tiny sandblaster, I think I can clear off the corrosion and epoxy well enough to try again with good old JB Weld epoxy. It’s not rated for underwater use, so I don’t expect long-term goodness, but it’ll be an interesting comparison.

Bonus: the slicer will start with a uniform gray surface!

2018-11-01