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?

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
Bird Feeder Season

Word got around quickly after I set up the bird feeder at the corner of the patio, one week before Mary’s Project Feederwatch data collection started up:

Nuthatch on patio

You can tell this chipmunk wasn’t at all bothered by my presence:

North end of southbound chipmunk

We call them fur birds, but they don’t count for Feederwatch:

Chipmunk in vacuum cleaner mode

A few days later, I put a casserole of fresh-cooked brown rice on a patio table to cool, only to have a raccoon drag it off. Of course, the Pyrex bowl shattered on the concrete: neither of us got much of the rice…

2013-12-08
Shagbark Hickory Nut Season

Mary managed to outcompete the local squirrels to the tune of 10 pounds of Shagbark Hickory nuts, which we’ve been enjoying after supper. The thickly armored nuts shrug off ordinary nutcrackers, so we deploy heavy weaponry: good old 10WR Vise-Grip pliers:

Cracking nickory nuts with a Vise-Grip

She describes the process better than I; for what it’s worth, I work on one nut at a time. We both celebrate when a shell releases its nut with minimal damage; most often, we extract fragments into a pile like the one shown. I can process half a dozen nuts before deciding I’ve had enough.

I’d be in favor of a genetic modification producing a fluorescent green shell, because overlooking a minute piece of shell in that pile of nutmeat is a Very Bad Thing…

Some Vise-Grip history may be of interest.

2013-11-17
LED Bug

Our Larval Engineer has a bug report that blows away anything I’ve ever seen:

Check out her post for the rest of the story…

Forgot to mention this when she first told me about it; the discussion of LED and CFL lifetime brings it to mind.

2013-10-27