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.

Category: Oddities

Who’d’a thunk it?

MHV LUG Lightning Talk: Intro to NSA Hardware Implants

Meme – Nixon – I see what you did there – 5x38k

I did five minutes of standup comedy at yesterday’s MHV Lug meeting, pointing out some of the more interesting ways to compromise a PC when you have an infinite budget for development and consumables.

You don’t get my patter with the PDF (unless you had access to the room’s bugging hardware), but the links may come in handy in the unlikely event you haven’t been following the story closely.

If you have a security clearance or are in line for one, you probably shouldn’t click on the link, because it contains copies of pages from the leaked NSA catalog:

I See What You Did There – NSA Hardware Guide

2014-01-09
Santa Ride: Crash Report

While walking from the Metropolitan Museum of Art to Grand Central on a frigid post-Christmas December evening, we encountered this storefront display:

Santa Ride – car

A closer look at the monitor in the background:

Santa Ride – crash report

Hmmm. Bit of a surprise: not a Windows box.

After walking two miles along Madison Avenue, I didn’t see one single item in the store windows that I’d buy, even in the after-Christmas discount season. Mary wasn’t enthralled by a pair of diamond-encrusted emerald earrings the size of my thumbs, either, which is likely a Good Thing.

We stopped in the Ugg Boot Store, both to warm up and so I’d know what all the spammers have been hawking…

2014-01-07
Kenmore Dishwasher Sound Deadening Sheets: Slip Sliding Away, Redux

The springs balancing the dishwasher door started twanging again, which I now know is the diagnostic sign that an asphalt sound deadening sheet has slipped off the tub. A sheet on the right side almost perpetrated a clean escape, but the flap drooping over the spring gave it away:

Dishwasher sound deadener – slipped away

Another sheet on the left side was inching away, but hadn’t quite gotten over the fence:

Dishwasher sound deadener – slipping away

They’re pretty much a rigid solid at room temperature:

Dishwasher sound deadener – wrinkled asphalt sheet

It puts one in mind of the pitch drop experiments now running in various labs. In this case, we now know it takes about four years for an asphalt sheet to slide completely off the tub; those two sheets were definitely in place when I buttoned it up after the previous one broke free.

I applied a heat gun to soften the sheets, then smoothed them around the tub again. This time I applied long strips of Gorilla Tape from one side to the other, rather than short strips of ordinary duct tape along the edges, and maybe this fix will outlast either the dishwasher or our tenure here, whichever comes first…

2014-01-04
Planetary Gear Bearing: Now With Knurling!
OK, I couldn’t resist. Tweaking a few lines of code wrapped a knurl around emmitt’s Gear Bearing for enhanced griptivity:

Knurled vs original Planetary Gear Bearing

That image has desaturated red to suppress the camera’s red burnout. It looks better in the realm of pure math:

Planetary Gear Bearing – Kurled – solid model

Reducing the tolerance parameter to 0.4 produced a surprisingly rigid, yet freely turning, bearing that required no cleanup: it popped off the plate ready to roll!

The heavy lifting in the OpenSCAD source code remains emmitt’s work. I replaced the outer cylinder with a knurl and simplified his monogram to stand out better amid the diamonds. This is the affected section:
```
... snippage ...
translate([0,0,T/2]){
	difference(){
//		cylinder(r=D/2,h=T,center=true,$fn=100);
		render(convexity=10)
		translate([0,0,-T/2])
			knurl(k_cyl_hg=T,
			k_cyl_od=D,
			knurl_wd=5.0,
			knurl_hg=5.0,
			knurl_dp=0.5,
			e_smooth=5.0/2);
		herringbone(nr,pitch,P,DR,-tol,helix_angle,T+0.2);
//		difference(){
			translate([0,-(D/2+4.5),0])rotate([90,0,0])monogram(h=10);
//			cylinder(r=D/2-0.25,h=T+2,center=true,$fn=100);
//		}
	}
	rotate([0,0,(np+1)*180/ns+phi*(ns+np)*2/ns])
	difference(){
		mirror([0,1,0])
			herringbone(ns,pitch,P,DR,tol,helix_angle,T);
		cylinder(r=w/sqrt(3),h=T+1,center=true,$fn=6);
	}
	for(i=[1:m])rotate([0,0,i*360/m+phi])translate([pitchD/2*(ns+np)/nr,0,0])
		rotate([0,0,i*ns/m*360/np-phi*(ns+np)/np-phi])
			render(convexity=10)
			herringbone(np,pitch,P,DR,tol,helix_angle,T);
}
```
I also added a few render(convexity=n) operations to improve the preview, but that’s just cosmetic.
2014-01-03
Emergency Eye Wash Station: Watch Out!

Spotted this in a greenhouse:

Cluttered emergency eye wash station

Just like fire extinguishers and bike helmets, you never know when you’ll need to use this thing in a hurry… then it’s too late to clean out all the crap that accumulates on any flat (or concave) spot.

Not that I’m completely innocent, of course.

The DSC-H5 had been outdoors for a few hours, hiking with us at 25 °F, so the lens fogged instantly when we walked through the greenhouse door.

2013-12-28
Gauge Block Set Oiling

Ray’s Rule of Precision:

Measure with a micrometer. Mark with chalk. Cut with an axe.

While pondering the problem of having the Sherline’s Z-axis anti-backlash nut unscrew at the top of its travel, I excavated the gauge block set and measured the gap between it and the bearing preload nut:

Sherline Z-axis leadscrew nut – gauge block

Turns out that it’s 0.1340 inches, determined by bracketing the sliver above that 0.1300 block with feeler gauges. I don’t believe that last zero, either, as the Basement Shop was about 10 °F below the block’s 68 °F calibration temperature. [grin]

The actual size of that gap makes absolutely no difference whatsoever, but fooling around with the gauge blocks gave me an excuse to renew my acquaintance with them and, en passant, massage some oil over their long-neglected bodies:

Gauge block set

I used La Perle Clock Oil, which isn’t Official Gauge Block Oil, but doesn’t go bad on the shelf. Verily, this bottle may be the last of its kind, as it’s no longer available from any of the usual sources; it appears I bought it back in 2000.

The blocks are in good shape, probably because they don’t often see the light. FWIW, I have experimentally determined that my body oil doesn’t etch fingerprints into steel.

The block set, which is similar to a current box o’ blocks from Enco, claims “Workshop Grade”, but the ±0.00050 inch = 1.27 μm tolerance shown in the top row of the labels is much worse than even grade B’s sub-micron tolerance. That newer box claims “Economy” accuracy with the same spec, so I suppose somebody kvetched about mis-using the terms.

Ah, well, they’re far better than any measurements I’ve needed in a while and entirely suitable for verifying my other instruments.

2013-12-26
Northern Cardinal: Window Strike

For all the usual reasons, I didn’t hang the mesh netting over the bedroom window when I put up the bird feeder on the far corner of the patio:

Male cardinal – window strike death

That window is far enough away that birds get up to full speed and low enough that they can see through the windows on the far side of the bedroom to the bushes and trees north of the house.

The mesh is up now and I feel like crap.

2013-12-21