Machine Shop – Page 215 – The Smell of Molten Projects in the Morning

Snowthrower Shear Bolts

The snowthrower (I’ve always called it a snowblower, but that’s just me) ate a ski pole (*), handle-tether-end first, and the right-side shear bolt worked perfectly when the right-hand auger slammed to a stop. A bit of drift punch rapping extracted the sorry lump at the bottom:

The missing nut and bolt head may eventually surface, but I’m not losing any sleep over them.

I popped a replacement shear bolt from the heap (thank you, Aitch!) and thought the nut went on rather stiffly. The nuts have a crimp in the middle to make them vibration-proof, but this one seemed stiffer than usual and, lo and behold, the bolt snapped just before I thought the nut had gotten far enough.

The nut on the second replacement shear bolt required much less torque, didn’t (let me) snap the bolt, and I finished the mission. That’s the third or fourth shear bolt I’ve used since getting the thrower in 2007, so there’s a package of six in transit.

Part Number 710-0809A, 5/16-18 x 1.5 inch.

(*) One of Mary’s gardening cronies works for a sporting goods store, has access to an unlimited supply of slightly bent ski poles, and shares the bounty for use as garden stakes.

2016-12-24

Under-cabinet Lamp Brackets: Close-fit Power Plug

Adding a little tab to the angled brackets prevents them from pivoting while you’re tightening the mounting screw into the brass insert:

Kitchen Light Bracket - angled lip - Slic3r preview — Kitchen Light Bracket – angled lip – Slic3r preview

The trick with those tabs is to chop ’em off halfway to the tip, because there’s no point trying to print a wedge that ends with a sharp edge:

Kitchen Light Bracket - angled - tab cutoff - solid model — Kitchen Light Bracket – angled – tab cutoff – solid model

Generating & positioning that block goes a little something like this:

translate([0,
           2*MountBlock[1] - LEDEndBlock[2]*sin(StripAngle),
           MountBlock[2]/2 + MountHeight - 0.5*LEDEndBlock[2]*cos(StripAngle)])
    cube(2*MountBlock,center=true);

As a rule of thumb, there’s no point in fussing with smaller shapes when a big one will suffice…

This LED strip fits under the cabinet over the butcher block countertop next to the stove, which turns out to be Just Barely longer than the strip itself:

Under-cabinet light - cramped power plug — Under-cabinet light – cramped power plug

The OEM straight-on coaxial plug (near the bottom of the picture) attached to the wall wart cable obviously wouldn’t fit in the available space, so I gimmicked up a right-angle adapter by the simple expedient of shortening the solder lugs of a plug from the heap (which, admittedly, doesn’t quite fully seat in the socket), bending them sideways, soldering a pair of wires, heatshrinking appropriately, then coating wires + plug with JB Kwik epoxy. The other end of the wires gets a coaxial jack that miraculously fits the OEM plug, styled up with more heatshrink tubing. Not pretty, but nobody will ever see it.

Unlike the LED strip under the other cabinet, this IR proximity sensor doesn’t mind having a wood edge next to it and, thus, didn’t need a strip of tape to keep it happy.

2016-12-21

Under-cabinet Lamp Brackets: Angled Edition

The LED strip lights have a reasonably diffuse pattern with an on-axis bright area that puts more light on the rear of the counter than seems strictly necessary. Revising the original brackets to tilt the strips moves the bright patch half a foot forward:

Kitchen Light Bracket - angled - solid model — Kitchen Light Bracket – angled – solid model

For lack of anything smarter, the angle puts the diagonal of the LED strip on the level:

Kitchen Light Bracket - angled - Slic3r preview — Kitchen Light Bracket – angled – Slic3r preview

The translucent block represents the strip (double-thick and double-wide), with a peg punching a hole for the threaded brass insert.

Although the source code has an option to splice the middle blocks together, it can also build them separately:

Kitchen Light Bracket - angled - LED block — Kitchen Light Bracket – angled – LED block

Turns out they’re easier to assemble that way; screw ’em to the strips, then screw the strips to the cabinet.

I moved the deck screw holes to the other end of the block, thus putting the strips against the inside of the cabinet face. It turns out the IR sensor responds to the DC level of the reflected light, not short-term changes, which meant the reflection from the adjacent wood blinded it to anything waved below. Adding a strip of black electrical tape killed enough of the reflected light to solve that problem:

Under-cabinet light - IR sensor shield — Under-cabinet light – IR sensor shield

The tape isn’t quite as far off-center as it looks, but I’m glad nobody will ever see it …

The before-and-after light patterns, as viewed on B-size metric graph paper centered on the left-hand strip and aligned with the belly side of the countertop:

Under-cabinet light - straight vs angled patterns — Under-cabinet light – straight vs angled patterns

Those look pretty much the same, don’t they? So much for photography as evidence for anything.

The OpenSCAD source code as a GitHub Gist:

	// Mounting brackets for eShine under-counter LED lights
	// Ed Nisley KE4ZNU December 2016

	Layout = "Build";

	//- Extrusion parameters must match reality!

	ThreadThick = 0.25;
	ThreadWidth = 0.40;

	HoleWindage = 0.2;

	Protrusion = 0.1; // make holes end cleanly

	inch = 25.4;

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

	//———-
	// Dimensions

	MountHeight = (1 + 03/16) inch; // distance from cabinet bottom

	THREADOD = 0;
	HEADOD = 1;
	LENGTH = 2;

	WoodScrew = [4.0,8.3,41]; // 8×1-5/8 Deck screw
	WoodScrewRecess = 3.0;
	WoodScrewMargin = 1.5 * WoodScrew[HEADOD]; // head OD + flat ring

	Insert = [3.9,4.6,5.8 + 2.0]; // 4-40 knurled brass insert

	JoinerLength = 19.0; // joiner between strips

	LEDEndBlock = [11.0,28.8,9.5]; // LED plastic end block
	LEDScrewOffset = [1.0,8.2,0]; // hole offset from end block center point

	StripAngle = atan2(LEDEndBlock[2],LEDEndBlock[1]);
	echo(str("Strip angle: ",StripAngle));

	MountBlock = [WoodScrewMargin,(WoodScrewMargin + LEDEndBlock[1]*cos(StripAngle)),MountHeight];

	//———————-
	// 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(d=(FixDia + HoleWindage),h=Height,$fn=Sides);
	}

	//—–
	// LED end block with positive insert for subtraction
	// returned with mounting hole end of strip along X axis
	// ready for positioning & subtraction

	module EndBlock(Side = "L") {

	LSO = [((Side == "L") ? 1 : -1)*LEDScrewOffset[0],LEDScrewOffset[1],LEDScrewOffset[2]];

	rotate([-StripAngle,0,0])
	translate([0,LEDEndBlock[1]/2,LEDEndBlock[2]])
	union() {
	cube(LEDEndBlock + [LEDEndBlock[0],0,LEDEndBlock[2]],center=true);
	translate(LSO + [0,0,-(LEDEndBlock[2] + Insert[2])])
	rotate(180/6)
	PolyCyl(Insert[1],2*Insert[2],6);
	}
	}

	//—–
	// End mounting block with proper hole offsets

	module EndMount(Side = "L") {

	translate([0,0,MountBlock[2]/2])
	difference() {
	translate([0,MountBlock[1]/2,0])
	cube(MountBlock,center=true);

	translate([0,WoodScrewMargin,MountBlock[2]/2])
	EndBlock(Side);

	translate([0,WoodScrewMargin/2,-MountBlock[2]])
	rotate(180/6)
	PolyCyl(WoodScrew[THREADOD],2*MountBlock[2],6);

	translate([0,WoodScrewMargin/2,(MountBlock[2]/2 – WoodScrewRecess)])
	rotate(180/6)
	PolyCyl(WoodScrew[HEADOD],WoodScrewRecess + Protrusion,6);

	translate([((Side == "L") ? 1 : -1)MountBlock[0]/2,3MountBlock[1]/4,-MountBlock[2]/4])
	rotate([90,0,((Side == "L") ? 1 : -1)*90])
	translate([0,0,-2*ThreadThick])
	linear_extrude(height=4*ThreadThick,convexity=3)
	text(Side,font=":style=bold",valign="center",halign="center");
	}
	}

	module MidMount() {
	XOffset = (JoinerLength + MountBlock[0])/2;
	BridgeThick = 5.0;

	union() {
	translate([XOffset,0,0])
	EndMount("L");

	translate([0,MountBlock[1]/2,BridgeThick/2])
	cube([JoinerLength,MountBlock[1],BridgeThick] + [2*Protrusion,0,0],center=true);

	translate([-XOffset,0,0])
	EndMount("R");
	}
	}

	//———-
	// Build them

	if (Layout == "EndBlock")
	EndBlock("L");

	if (Layout == "EndMount")
	EndMount("R");

	if (Layout == "MidMount")
	MidMount();

	if (Layout == "BuildJoined") {
	translate([-(JoinerLength + 2*MountBlock[0]),0,0])
	EndMount("L");

	MidMount();

	translate([(JoinerLength + 2*MountBlock[0]),0,0])
	EndMount("R");
	}

	if (Layout == "Build") {
	translate([-MountBlock[0],0,0])
	EndMount("L");

	translate([MountBlock[0],0,0])
	EndMount("R");
	}

view raw

Kitchen Light Bracket – angled.scad

hosted with ❤ by GitHub

2016-12-20

Respooling Stainless Steel Thread

For various reasons, I needed a smaller quantity of that stainless steel thread / yarn, so I mooched an empty spool from Mary, ran a bolt through it with washers + nut on the far end, chucked the bolt in the lathe, and ran the spindle backwards at the slowest speed:

Stainless steel thread - smaller spool — Stainless steel thread – smaller spool

I started by letting the big spool unroll from the side, but that produced horrible twists in the slack thread. Remembering the lesson from our previous thread spool adventure, I put it on the floor and let the thread pull from the top:

Stainless steel thread - unwinding spool — Stainless steel thread – unwinding spool

It still accumulated a huge twist between the two spools, even while guiding it hand-over-hand onto the rotating spool. Either the factory lays the thread on the large spool with a built-in twist or, more likely, a multi-strand steel thread behaves like a spring, no matter what anybody wants, and comes off the spool with a nasty case of inherent vice.

Memo to Self: don’t let stainless steel thread slide through your hands under power, because some of the fuzz visible in the top picture will stay with you.

2016-12-14

Under-cabinet Lamp Brackets

These blocky brackets hold a pair of LED light strips in the recess under our 1955-era kitchen cabinets, to let the light cover the entire counter:

The large holes are for drywall screws into the cabinet, the smaller ones for 2.5 mm SHCS holding the strips to the brackets. I drilled those little holes out and installed 4-40 brass inserts; this being a one-off installation, the source code doesn’t include that change.

There’s not much to see after they’re installed:

Under-cabinet light bracket - center joiner — Under-cabinet light bracket – center joiner

I’d hoped to swap the ends of the strip to power it from the right end, but the guts aren’t symmetric and you can’t just flip it end-for-end:

eShine LED Under-cabinet light - disassembled — eShine LED Under-cabinet light – disassembled

That’s an add-on unit without the IR proximity sensor circuitry and power switch, but with the same overall layout. You take it apart by pressing the obvious latch on one of the endcaps, then gently prying the plastic away from the aluminum extrusion, taking care not to wreck the coaxial socket. Reassemble in reverse order.

The OpenSCAD source code as a GitHub Gist:

	// Mounting brackets for eShine under-counter LED lights
	// Ed Nisley KE4ZNU December 2016

	//- Extrusion parameters must match reality!

	ThreadThick = 0.25;
	ThreadWidth = 0.40;

	HoleWindage = 0.2;

	Protrusion = 0.1; // make holes end cleanly

	inch = 25.4;

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

	//———-
	// Dimensions

	MountHeight = (1 + 3/16) * inch – 5.0; // under-cab space – base thickness

	THREADOD = 0;
	HEADOD = 1;
	LENGTH = 2;

	WoodScrew = [4.0,8.3,41]; // 8×1-5/8 Deck screw
	WoodScrewRecess = 2.0;

	LEDScrew = [2.0,4.5,8.0]; // M2.5×10 SHCS

	LEDScrewOffset = [1.0,8.2,0]; // hole offset from center point
	JoinerLength = 18.1; // joiner between strips

	EndBlock = [11.0,28.5,MountHeight]; // mounting block size for ends

	//———————-
	// 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(d=(FixDia + HoleWindage),h=Height,$fn=Sides);
	}

	// End mounting block with proper hole offsets

	module EndMount(Side = "L") {

	LSO = [((Side == "L") ? 1 : -1)*LEDScrewOffset[0],LEDScrewOffset[1],LEDScrewOffset[2]];

	difference() {
	union() {
	cube(EndBlock,center=true);
	translate([0,1.5*WoodScrew[1],0])
	cube(EndBlock,center=true);
	}

	translate(LSO + [0,0,-EndBlock[2]])
	rotate(180/4)
	PolyCyl(LEDScrew[THREADOD],2*EndBlock[2],4);

	translate([0,(EndBlock[1] + 1.5*WoodScrew[1])/2,-EndBlock[2]])
	rotate(180/6)
	PolyCyl(WoodScrew[THREADOD],2*EndBlock[2],6);

	translate([0,(EndBlock[1] + 1.5*WoodScrew[1])/2,(EndBlock[2]/2 – WoodScrewRecess)])
	rotate(180/6)
	PolyCyl(WoodScrew[HEADOD],WoodScrewRecess + Protrusion,6);

	translate([((Side == "L") ? 1 : -1)*EndBlock[0]/2,0,0])
	rotate([90,0,((Side == "L") ? 1 : -1)*90])
	translate([0,0,-2*ThreadThick])
	linear_extrude(height=4*ThreadThick,convexity=3)
	text(Side,font=":style=bold",valign="center",halign="center");
	}
	}

	module MidMount() {
	XOffset = (JoinerLength + EndBlock[0])/2;

	union() {
	translate([XOffset,0,0])
	EndMount("L");

	cube([JoinerLength,EndBlock[1],EndBlock[2]] + [2*Protrusion,0,0],center=true);

	translate([-XOffset,0,0])
	EndMount("R");
	}
	}

	//———-
	// Build them

	translate([0,0,EndBlock[2]/2]) {
	translate([-(JoinerLength + 2*EndBlock[0]),0,0])
	EndMount("L");


	MidMount();

	translate([(JoinerLength + 2*EndBlock[0]),0,0])
	EndMount("R");
	}

view raw

Kitchen Light Bracket.scad

hosted with ❤ by GitHub

2016-12-13

Satco PAR30 LED Floodlight vs. Halogen

I replaced a dead 75 W halogen PAR30 bulb over the kitchen sink with a Satco S9415 LED bulb that was, at the time, advertised as “75 W equivalent”:

Satco S9415 PAR30 LED Bulb - specs — Satco S9415 PAR30 LED Bulb – specs

It’s noticeably less bright than the surviving halogen bulb, which is what you’d expect when 950 lm goes head-to-head with 1100+ lm (based on casual searching), but with a similar color temperature and beam pattern, so it’s Good Enough. I should have bought two and converted the halogens into glass sculptures.

The difference between the 22.8 year Life and the 3 Year Warranty always seems amusing. The warranty requires returning the bulb, so that’s about useless …

2016-12-10

Kinesis Freestyle2 Keyboard vs. Linux

My old Microsoft Comfort Curve keyboard having gotten on in years, I picked up a Kinesis Freestyle2 (KB800B for PC) split keyboard:

Kinesis Freestyle2 - desk layout — Kinesis Freestyle2 – desk layout

The little hinged dingus (“Pivot Tether”) between the halves (“Keying Modules”) has two posts that pop into into sockets on the back of the halves and are retained by the two sliding latches. The cord connecting the halves allows 9 inches of separation; I don’t need that much, but more than zero seemed about right.

Kinesis also sells various staggeringly expensive (IMO) doodads that attach to the back of the keyboard to “tent” the middle upward with varying degrees of refinement. None of the doodads offer to raise the back of the keyboard, which I vastly prefer to the current flat or reverse-tilted recommendations.

The keyboard & trackballs rest on a homebrew shelf that slides out from where the desk used to have a center drawer, which puts the keyboard slightly above elbow height (heck, slightly above thigh height), whereupon tilting the keyboard puts the keys exactly where they should be. I bandsawed some wood into vaguely triangular sticks, topped them with foam sheets, and tinkered for best tilt. Works for me, anyhow.

The Compatibility section of the Freestyle2 User Manual describes the “special driverless hot keys”: Most will also work with Linux. Four of them do not work, to the extent that they don’t even send key codes to exv. Some searching suggests this is an intractable problem, for reasons that make no sense to me. Their HID Usage Codes, whatever that might mean:

Kinesis Freestyle2 - inert key codes — Kinesis Freestyle2 – inert key codes

That’s only a minor inconvenience; I prefer a physical calculator and don’t spend much of my life listening to anything through the headphones.

For whatever it’s worth, the scroll ring on the most recent warranty replacement Kensington Expert “Mouse” (I think it’s the third) has worked flawlessly for years; they seem to have fixed the sudden death syndrome.

2016-12-09