Today’s banner: long curls of aluminum swarf issued from a drilling operation on the lathe.

These were produced by a new 7/16″ drill bit. The drilling operation was quick, the bit requiring very little applied force. In fact, a large increase in force behind the bit results in only a moderate increase in the rate of material removal. This is characteristic of sharp tools, in general — and this is why sharp tools are easy to use.

Dull tools, of course, are characterized by frustration. Using a dull tool is a good way to make the tool duller. And that is why we have a good set of bits that have remained sharp for quite a long time. Of course, we have yet to master the art of sharpening bits. Especially the really tiny ones.

And since our machine work tends toward the small scale, we have a steadily-increasing supply of upside-down bits in our bit-cases (they’re upside to remind us that they’re dull). In our investigation into bit-sharpening methods we’ve encountered opinions held with fanatic conviction:

“A Drill Doctor is the way to go!”

“No, make your own sharpening jig!”

“Sharpening jigs are only good for practicing your sledgehammer technique.”

“When I was a boy we sharpened our bits by hand! Barefoot! In the snow, and uphill both ways!”

“Throw them away, and buy new ones from us! In bulk! Look, they’re shiny!”

“We’ll sharpen them for you. We charge only a modest fee…”

So, anyway, we have a nice wet-grinding wheel. If anyone knows how to use it, please drop us a line.

Best — stochastic.


Today’s banner: a disintegrated Bowden cable, an erstwhile component of the tensioning mechanism in our beloved squiggly-magnetic-dial-indicator stand thingy:

The squiggly-magnetic-dial-indicator stand was, in turn, part of our notatripod, formerly an integral chunk of our makeshift photo studio. This is what the indicator stand looks like now:

On one hand, we are no longer impressed by the design and construction of this device. On the other hand, it is highly likely that we have unknowingly abused the poor thing, and we mourn the loss of our notatripod — it was so very useful. On the third hand, we’re pretty sure we can fix it; but on the fourth hand, we wonder whether it will simply break again.

We seem to have run out of hands while we weren’t looking. (sigh)

Sleep well tonight — stochastic


Today’s banner: a centrifuge, about ten times as tall as the guy standing beside it. (But he’s only three inches high.)

And below is a bucket, with an attractively decorated lid (or at least it looks like a bucket):

It contains a thing. The thing looks electric:

Indeed, the thing has an electrical cord, dials, and what appears to be another thing that perhaps spins:

The bucket fits nicely on top of the electrical thing. It’s a tiny electric washing machine! Its name is “Wonder Washer“, an apparently unbranded Chinese product (not to be confused with “Wonder Wash“, which is a totally different product powered by the human arm).

We like the Wonder Washer because it’s so compact when stored, and it’s highly-portable. It works very well for small items (socks, underwear, washcloths, dishtowels, rags, …). It also works fairly well for T-shirts. It’s pretty much useless for anything more bulky, like sweaters, jeans, towels, or sheets. If you try to use this little washer to wash any of these big items, the little washer makes very sad groaning noises. Also, it’s kind of loud. Not terribly so, but loud enough that you can hear when it finishes washing, even if you’re in the next room. A full load of laundry is 8-10 liters:

A similarly-sized laundry centrifuge, shown below, works well with the tiny washing machine. This spin dryer is made by another company entirely — The Laundry Alternative, Inc (who also make the afore-mentioned human-arm-powered Wonder Wash, which is distinct from the Wonder Washer, whose name-similarity is confusing). This spin dryer is very quiet, and it works extremely well. You’ll still need to line-dry or tumble-dry your clothes after spinning in this device. But we’ve found that if you spin your clean wet clothing in this little centrifuge, and then finish drying on a clothesline or in the tumble dryer, they dry faster than after spin-drying in a standard washing machine.

We’ve photographed a little guy standing next to the spin dryer, in order to give you sense of scale. (But actually he’s only there for the fun of it. The spin dryer is not, in fact, sixty feet tall.):

Best wishes,



Today’s banner: our improvised photo studio, comprising a dinner table, a curtain rod, a desk lamp and two squiggly-headed floor lamps, two rolls of paper, and several tiny figurines cavorting on the equipment. No, no, please try to contain your envy, not everyone can have a setup this snazzy:

The figurines are fun but otherwise serve absolutely no purpose whatsoever, except maybe a kind of conspicuous consumption: “… our photo studio has a troupe of tiny acrobats that perform on the lighting equipment. They’re just for atmosphere. They help keep the mood light.”

Although the studio is improvised, it works so well that we’re keeping it.

Have a good night — stochastic.

impact crater

Today’s banner: an impact crater, steel having smashed into aluminum at the mind-numbing speed of — wait for it — zero. After we’ve center- or prick-punched a tiny indentation in the aluminum surface, this is what it looks like up close:

To make such an indentation, one carefully aligns the tip of a punch to the desired spot on the workpiece surface, and then carefully taps the other end of the punch with a small hammer. As in our previous blog posts, the black vertical lines in this image are the rules of an inkjet-printed millimeter ruler, presented for scale. As you can see from the crosshairs, we totally nailed it.

Here’s a closer image of another punch, which, again, we nailed:

Sleep well tonight — stochastic.


Today’s banner: metalworking layout tools, improvised, on a glass surface plate (also improvised).

We recently overheard an engineering student ask a really good question: where does precision come from? The manufacture of nearly every precision instrument derives that precision, ultimately, from something else that’s even more precise. Think about that. Infinite recursion, ad infinitum, ad nauseum… Where does it end? What’s the base case? It must be a platonic ideal. Perhaps it pulls itself out of its own navel or something. A realization of the Omphalos Hypothesis. It must invent itself.

We tripped over to the local engineering college’s library where we found a copy of Foundations of Mechanical Accuracy by Wayne R. Moore, 1970, The Moore Tool Company. The copy we found was forty years old. During the last forty years, exactly twelve people had read it. This made us sad. We determined to make up for this dearth of readers by reading it several times.

We discovered that, in fact, the base case is the perfect plane. In the 1830s James Whitworth gave us a simple (if arduous and tedious) method for establishing as a flat plane of reference the surface plate. Surface plates are made as large as needed, and since precision instruments are used to build really big things — think “naval engineering” — by large we mean large, heavy, and extremely rigid. Okay, they’re not as large as an aircraft carrier, but you could stretch out and take a nap on one. If you don’t mind a really hard mattress.

The best surface plates are made of cast iron, or ceramic, or even glass, and are flat to within a millionth of an inch. From this plane — as perfectly flat as we can make it — from this plane can be derived the straightedge, the square, and the precision ways of lathes and milling machines.

In Whitworth’s process, surface plates are manufactured in triplets. Each surface plate is repeatedly compared to the other two, mutually proving each other, their surfaces gradually refined by hand, using a scraper, until no imperfections can be detected. How are imperfections found? One way is to paint one surface with a pigment. Try to mate the surfaces of two plates: on the dry surface, any high spots get inked, and any low spots stay dry. When the pigment is uniformly transferred from the wet to the dry surface, we’ve reached the limit of our ability to detect imperfections.

But why make three at a time? It’s a matter of practicality. Surface plates are usually rectangular, so the only easy rotation is 180 degrees. Now image placing a horse’s saddle upside-down atop another saddle. (I know this seems like a totally unrelated tangent, but bear with me.) If the upside-down saddle is rotated ninety degrees, the two saddles will mate well, even though they’re not at all flat. Now rotate that upside-down saddle by 180 degrees. They still mate.

If you do this with a pair of rectangular surface plates with mirrored but matching saddle-shaped deformations, they will appear to mate well. Now suppose the third plate also has a mirrored deformation that mates well with the first plate. Well, it mirrors the first plate, but not the second. The second and third plates won’t mate. So three plates will detect this kind of deformation, allowing the maker to correct the problem.

These days you can’t get much flatter than a good pane of glass. Through an entirely different process, the Pilkington process, so-called “float glass” derives its flatness from gravity. It’s really cool (or rather, very hot): molten glass floats on the surface of molten metal, an alloy chosen to have a low melting point — lower than that of glass. The glass is allowed to cool enough to solidify on the surface of the molten metal. Then you just pluck it out of the pool of molten metal. Not with your bare hands.

As a surface plate in a production line or for large metalwork, a pane of glass would be utterly worthless. But for the hobbyist working on a very small scale, a good, thick pane of glass works great.

We’re going to try using a pane of glass as a surface plate, depending on it to draw really straight lines. We’ll use it derive the centerline of a 2-1/2″ workpiece of 1″x1″ extruded aluminum. (This will only work, by the way, if we know the faces of the workpiece are flat — which we assume but won’t confirm, but could confirm with the pigment trick — and that the faces are parallel. But if it works — if we establish a centerline and can prove it — the parallelism of the workpiece faces will also be confirmed.)

That’s a tube of oil paint from the local art supply store. It’s Prussian blue. Here it’s being smeared onto one face of a small piece of 1″x1″ extruded aluminum. The main reason we’re using it is that scribed lines on bare metal can be hard to see, but a line scribed through a layer of pigment is bright and easy-to-see. We could have used a felt-tipped marker. But we like Prussian blue — it reminds us of finger-painting. Here’s the completed coating:

The scribe is clamped into a dial indicator holder doohickey with a magnetic base, which is stuck to a small piece of flat metal (stolen from an engineer’s metalworking protractor). Here the tip of the scribe has been adjusted to point approximately at the centerline of the workpiece. We intend to find the exact centerline. By simply sliding our scribe-dial-indicator-holder-doohickey-with-a-magnetic-base across the glass surface plate, we scribe a short test line:

We flip the workpiece and try to rescribe the same line, without readjusting the scribe:

When we examine the two test lines, we find that — as expected — they don’t quite align:

Now we adjust the scribe tip. We adjust it to fall between the first two test lines. We then make a new pair of test lines. We repeat the process until the tests lines are as well-aligned as we can make them:

Then, sliding our doohickey, we try scribing a complete centerline. Then we test the centerline: we flip the workpiece, and without adjusting the scribe, we try again, and we check for agreement along the full length:

The scribed lines match, under unaided visual inspection. Just for the heck of it, we added crosshairs. Now comes the fun part: we inspect the line we made:

More detail! We must magnify! We stick the workpiece under a microscope. Here we’ve inkjetted a small millimeter ruler on paper, and we’ve placed it directly below the scribed line, for comparison under the scope:

Our centerline is the single vertical line. Pretty freakin’ spot-on. The parallel scribed lines are our crosshairs. For the heck of it we check the height of the scribe tip:

It lies on the 1/2″ mark, and to the limits of our visual inspection, the alignment is perfect.

Best wishes — stochastic



papercraft keep

Today’s header: an internal dispute in the Wizards’ Keep. Which we made. With paper and glue. (We’re nerds.)

We wanted to give you a complete tour of the keep, and the lake, and the nearby woods, and the surrounding countryside, and — okay, we have more papercraft terrain than can reasonably fit into a single blog post. It’s all the same terrain, part of the same landscape — it’s just really big. Here are two of the five floors of the keep:

The front gate, manned by armed guards:

The entrance to the stables, made of masonry to protect the livestock and the things that we don’t eat but we keep for riding. (Words are hard.) (We’re sure there’s a term for horseys and donkeys and suchlike, but we’re not sure what it is.)

The hayloft is so-situated as to permit dropping bales at the stable’s entrance for easy distribution among the stalls. The page is about to be in trouble for goofing-off.

The keep’s military resources protect a nearby village, and in turn the keep is supported and staffed by the villagers. Here’s one of their cottages:

We’d like to say that a nearby river affords access for commerce, but actually we just wanted a lakeside view. The lake is fed by springs, and in turn drains via an underground river.

As often happens around here, a cat dropped by during photography. Or perhaps it was a catmonster! rampaging through the countryside!

Oh no! The catmonster has invaded the keep, penetrating the defenses as though they were… heh, paper.

Oddly, the catmonster was very careful to not sit on anyone, nor to destroy the walls. Upon reflection, we believe he simply wanted to know whether he would fit in the atrium.

Best wishes,



P.S.: Most of the designs come from Fat Dragon.