Just another AI test. I gave Gencraft.com the names of some famous people. I took the better of the two pictures generated for each name. Then I matched them to actual pictures. I tried to avoid iconic real images, where possible. Continue reading Post #1850: Which pic is real?
It’s funny how catastrophes linger in our collective memory, but near-catastrophes fade.
Fifteen years ago, the “housing bubble” that developed during the Bush administration finally collapsed, and almost took down the U.S. banking system with it. To the point where the Federal Deposit Insurance Corporation (FDIC) ran a negative fund balance, due to the wave of bank failures (below).
Source: FDIC, , courtesy of the Federal Deposit Insurance Corporation (FDIC), s
By now, most have forgotten how crazy housing prices were in some parts of the country. And what extraordinary measures the Federal Reserve took to avoid a complete collapse of the U.S. financial system.
We’re still dealing with the fallout from the 2008 near-catastrophe. In particular, that led to more than a decade during which the Federal Reserve kept interest rates low. Lower than the underlying rate of inflation, in fact. As I see it, the Fed recapitalized a bankrupt U.S. banking industry on the backs of U.S. savers.
But that era of below-zero real interest began to end a couple of years ago.
And nothing much has happened. Yet.
Yesterday, a friend pointed out that some economic analysts see the U.S. housing market as once again ripe for a collapse in prices. Given that I own a house, I thought it was well worth taking the time to look at current U.S. housing market data. And while I was originally skeptical, I’d now have to say, he has a point. There’s not a lot of sunshine in the current housing market data.
With apologies to Song of Solomon, 2:12. But surely the blog title makes at least as much sense as ” .. the voice of the turtle … “. Whatever. This post isn’t about Bible specifics.
The background here is that a friend, has a little kid, who really likes a stuffed toy, that has a broken electronic voice-box.
The catch is that the toy in question is a 25-year-old plush chihuahua dog. It was a promotional giveaway from Taco Bell. It was never meant to be repaired.
There are probably a lot of these exact Taco Bell chihuahua dogs still in existence. You can buy one on Etsy (below). But at this point, it’s a fair bet that the 25-year-old batteries in the device either have died, or will soon die, if the toy is actually used as a toy. So if you want one that talks — and the little girl in question definitely wanted that — you’d best be prepared to replace the batteries, at least.
Source: Etsy (link to page).
So, would I mind trying to fix it? Needless to say, replacement parts may be an issue. And in terms of helpful instructions on the internet, I found none.
In the end, I tried to fix four broken Taco Bell chihuahua voice boxes. You never know who might want to read about fixing a mute Taco Bell chihuahua plush toy. So I thought I’d document the fix. It’s not as if hordes of folks read this blog, even on my best days. Bottom line, three out of four now work. Continue reading Post #1842: … and the voice of the chihuahua is heard in our land, …
This post is a first followup to Post #1667, Döstädning and the problem of small stuff. In this post, I describe how I mostly-muddled-through getting rid of a roomful of miscellaneous stuff. Continue reading Post #1838: It all boils down to the size of your junk drawer.
My wife and I just returned from a brief vacation in Ocean City (OC), Maryland.
Our annual OC vacation has changed since our kids have grown up. Without the need to entertain the kids, the beach experience becomes a lot more, eh, ritualized, for want of a better term. Continue reading Post #1838: Two electrical issues from our recent vacation.
The statistically savvy among you might have noticed something odd about the graph at the end of the last post.
When I let unconstrained math (via Excel) determine the best straight-line fit to these data points, it appears to tell me that these cars lost about 4% of battery capacity for every 10K miles.
But …
But what that doesn’t do is guarantee that with zero miles, I predict that you’ll have 100% of original capacity.
And that matters, because it looks like a lot of these cars must have lost a lot of range early on, that is, at low mileage. And that loss of battery range doesn’t get factored into the 4% per 10K range loss estimate.
So this is a rare instance of a straight-line fit for which you are justified in “setting the intercept” manually, rather than letting an unconstrained least-squares fit to the data do it. By definition, the line has to pass through zero miles matching 100% of original range.
Look what happens when I do that:
On average, pinning the linear trend to pass through 0 miles = 100% of original range, range loss is more like 8% per 10K miles.
The whole cluster of dots is quite “low” on that graph, so to speak. Those cars on average followed a path of losing a lot of range early on. And having the loss taper off to a mere 4% per year.
My guess is that exponential decay is the line you’d like to fit, for something wasting away. But I can’t seem to get Excel to give a trend passing through the required point, with the required shape. So I freehanded what I think the Conventional Wisdom says about the time-path of battery loss.
No matter how you cut it, the actual observed battery loss over this range amounts to much more than 4%/10K miles. The mid-point of the fitted line sits around a 40% loss over 5K miles. That’s the 8%/year calculated when the regression line was pinned at 100% capacity at zero miles.
George Akerlof, economist, once wrote a piece whose title began “The Market for ‘Lemons’: ” The paper is pretty deep, but the takeaway is pretty simple. In this case, it boils down to: People sell their cars when those cars are lemons, not when they are peaches.
That’s one obvious explanation of why these losses appear far larger-than-expected. (Where, lurking in the background is the idea that EVs lose, oh, like two percent a year, maybe, based on looking at a few graphs in the past.) The point is, maybe most of these cars appear in the used car listings precisely because they had above-average battery capacity losses. And that’s why their prior owners sold them. And I’m seeing them.
The other possibility is that the mileage estimated from the dashboard readout is substantially biased downwards. (I know it has a high variance, as it depends on recent driving style. Leaf aficionados refer to it as the “guess gauge”. That should just add noise, not bias, I think.)
There is one element of bias in what I did in my calculation, in that the range bars are each about 8 percent thick. For example, when I saw four range bars, my calculation assumed the car was (4/12 =) 33% charged. But if four bars is really just 3.5 bars, on average, then that charge level is actually just a shade over 28%, on average. I would then triple that error in arriving at 100% of charge, and so end up understating total range by a factor of about 15%.
Adjusting for that would require multiplying my range estimate by (1/.85 =) about 18%. The upshot is that what looked like a 60-mile range based on the dashboard could plausibly be a 70-mile range in reality.
That said, I’m not sure this materially changes the situation. No matter how I slice it, the range of the car I’m interested is far lower than the Recurrent.com estimate that I had been looking at.
Finally, I can’t fully discount that the losses observed in this low-end used car sample are typical of a random sample of Leafs. But if it were, I doubt there’d be many Leaf fans out there.
On net, I think the explanation is that I’m looking at a market for lemons. By looking only at the low-cost end of the market, and only looking at what people are trying to sell, I’m probably looking at a fairly biased sample of all Leafs.
Unfortunately, that’s the sample of cars I’m buying from, if I continue down this path. Perhaps time for a re-think.
Yeah, well, this was not unexpected. One thing at a time. Continue reading Post #1817: Bow works well, violinist does not.
In brief: I finished rehairing a cheap fiberglass bow by making and installing a version of the tip wedge from this YouTube series by Gilles Nehr.
It’s crude. I used low-grade poplar wood from Home Depot, and shaped it using sandpaper.
But it works. My cheap bow is now (inexpertly) rehaired, as shown below.
The one thing I can say for sure is that this goes a lot faster once you have a little experience with it. Making and fitting the tip wedge took less than an hour.
Continue reading Post #1816: Bow rehairing finale, fitting the tip wedge.
This is the first time I’ve ever rehaired a violin bow. In this case, it’s a cheap fiberglass bow. Nothing much will be lost if I screw it up.
This is orders-of-magnitude harder than I thought it would be. I very nearly gave up when I finally figured out everything the task entails.
Good sense would dictate abandoning this project. Pride goads me onward. I refuse to call it quits and admit my mistake.
We’ve fought lengthy wars based on more-or-less the same rationale. So don’t judge me.
In any case, this entire post is about carving and fitting tiny little wooden wedges. The critical wedges that keep the horsehair in place, on the bow.
It’s every bit as hard as you might imagine. This is the step at which I balked originally.
Consult the checklist:
I assume you get the drift. Making and fitting the wedges, for the first time, is the worst kind of fiddly work.
And yet, that is not a recommended production technique if you run a gift shop.
I’m sure there are artisans who can knock these out in a trice.
Me? Start to finish, it took me about three hours to make and fit the wedge that goes into the heart of the frog.
The first trick is to know your limits. It’s just not possible to cut a piece of wood, to the required tolerances, using hand tools, in one go. Not for me, anyway.
In my case, I first split inch-long shards of wood of a segment of quarter-inch basswood poplar board, until I got one that was a snug fit for the width of the hole into which the wedge must fit. Then cut an over-long piece off that, and went to work with sandpaper, on that tiny fragment of wood.
Work it until it fits, or you’ve lost it on the floor, or you’ve made it too small and have to start over. Whichever comes first.
With enough monkeys, chisels, and time, you will eventually get one that fits. I think my winner was maybe my fourth attempt.
Some people start at the tip of the bow. Seemed like most started at the frog. Frog wedge looks much easier to do than the tip wedge. So that’s where I started.
You can buy ready-made “wedge blanks”, for just a few dollars. That is, you can buy the chips of wood, roughly the right size and shape. But my take on it is that the bulk of labor is in achieving the exact fit. You’ll put in that labor whether you buy a ready-made blank or make the rough chip yourself.
You cut the wedge so that the grain of the wood runs parallel to the length of the bow stick. This is to prevent the wedge from falling out in drier weather. Wood shrinks as humidity falls, but (essentially) only across the grain. Cut this way, the width of the wedge may vary, but the critical length dimension should remain very nearly constant, regardless of humidity. I kept losing track of which which direction was which, on the wedge, so I eventually colored the top face of the board with sharpie, so I would know which end was up.
Only one end of the hair comes bound, like that. The other is free because you have to cut the hank to size, to fit your bow.
You have to shove the bound end of the hair, into the cavity, so that the hair makes a right angle turn and the bound end of the hair sits flat on the bottom of the cavity. To make the end of the hank of hair more flexible, wet it, give it half a minute, then towel it dry. Use a sliver of wood or other dull object to press the end of the hank into place. I assure you that a screwdriver will cut horsehair under these conditions.
The frog slide — the bottom plate of the frog — has to slide over the hair, as it sits on top of the wedge. This means that the top of the wedge must be more-or-less flush with the top of the hole in which it sits. I lubed the frog slide with powdered graphite (sold as lock lubricant). That was a mess. I now see that savvier people get the same effect just by running a pencil down the slot into which the frog slide sits (reference).
But, ultimately, the wedge is what holds the horsehair in place. So, at the end of the day, you have to answer the following question:
This little wooden plug, inside the frog. Why is that called a wedge? It’s not obvious. Why is this a “wedge” and not a “plug”, say. Sure looks like a little wooden plug.
The reason is that you don’t insert the wedge vertically into its respective hole. Like a plug or a cork. Wrong-o. These are not plugs or corks.
In fact, if you cut it just right, you can’t insert it vertically. It should be just a hair too long for that. You insert the edge of the wedge furthest from the horsehair first, leaving the wedge tipped up slightly, high end resting on the hair. Then you press it flat, and in.
That motion — like closing a trap-door, as you push the wedge into place — locks the hair firmly against the wood of the bow or frog.
That’s what makes it a wedge. And that’s why the length dimension is critical, but the width, not so much. The distance between where the wedge meets the hair, and the back of the cavity, has to be just right.
That’s the theory.
In practice, expect some trial-and-error. The wedge is too big, so it won’t fit. Or too small, so it pops right back out. Or it pops out and gets lost in the rug. Or it fits, but you can’t squeeze the flat plate on the frog over top of it. And repeat.
Good news: Just three hours later, and one wedge is done and fitted.
Bad news: That’s the easy one.
Engineering-wise, the modern violin bow frog clearly has a lot of safety and redundancy built in. Multiple systems keep the horsehair in place. The hank of horsehair is both bound to itself (so individual hairs can’t pull out), and mechanically attached to the frog (so the entire hank can’t pull out, once the bottom plate is slid back into place.) And there’s yet another wedge — with glue, yet — to be driven under the ferrule of the frog. The pressure of the internal frog wedge merely aids those existing systems.
In short, this looks like overkill, for a modern bow frog. I’m guessing it’s done this way because this is the way it has always been done. Perhaps for older styles of frog, or those lacking the precision machining of a modern frog, or with horsehair that did not come pre-bound, the internal wedge fit matters more. But for this frog, from an engineering standpoint, it sure looks like any hard object that fills that hole would have kept the hank in place just fine.
The bow tip, by contrast, has zero redundancy. All that stands between the violinist, and performance disaster, is a single, tiny, carefully-fitted wooden wedge.
Which, by itself, is a reason to start at the frog, if this is your first bow.
Finally, in hindsight, I completely understand why the manufacturer glued the tip wedge in place, on this cheap bow. I may end up doing the same. We’ll see how it goes.
Maybe I should just stop watching YouTube.
On the one hand, I learn a lot.
On the other hand, I often learn just enough to get myself into trouble.
Such is the case with re-hairing a couple of violin bows.
The technology of the fiddle bow hasn’t changed in a couple of centuries.
What could possibly go wrong? Continue reading Post #1814: The unanticipated skill requirements for rehairing a violin bow.
