Author Archives: Danny Ayers

About Danny Ayers

Web research and development, music geek, woodcarver. Originally from rural northern England, now based in rural northern Italy.

Easter Island – a 21st Century Parable

Easter Island (Rapa Nui: Rapa Nui, Spanish: Isla de Pascua) is a Chilean island in the southeastern Pacific Ocean, at the southeasternmost point of the Polynesian Triangle. Easter Island is famous for its 887 extant monumental statues, called moai, created by the early Rapa Nui people.

A tiny green dot in an ocean of blue. People arrived there, it is reckoned, around 1000 AD . They got there by boat (canoe/catamaran) from one of the other islands of Polynesia, at least 2,600km away, probably before then from South America. These people knew how to use a boat. Whatever they brought with them, they developed a distinct local, rich, highly industrial culture. The society that developed locally was highly hierarchical, with class distinctions between a high chief, nine clan chiefs and then presumably, not quite so well recorded, everyone else.

They thrived. It’s reckoned that the population got up to 15,000 around the 1500s, despite only being 163.6 km^2. The island was biologically diverse, notably with plenty of trees. However they did experience ecological issues, effectively beyond their control, because they brought with them the Polynesian rat. This put paid to a lot of the local vegetation.
Note that this was long before the first recorded arrival of Europeans (Jacob Roggeveen, Dutch, 1722, followed not long after by yon Yorkshireman Cook).

By the time the Europeans got there, the islanders were already in deep crisis, population had descended to 2000-3000. When they were legion, the population had a voracious appetite for resources. They cut down trees (slash & burn presumably) to make space for agriculture. Without restraint.

What first comes to mind when you or I think of Easter Island, are the rows of huge stone heads called moai. For once when archaeologists handwave about’ritual objects’, the role of these is reasonably well known. Tied into the ancestor worship-based religion, the heads were those of noteworthys, chiefs and dieties. Their blank staring eyes were originally bright with coral. One aspect of them that I only found out fairly recently, made me do a double-take, is that the Easter Island statues face inland.

So, the population exploded, resources such as trees were hacked down, resources got thin on the ground and culture changed. It’s hard to see what happened here, but the focus of the religion had a shift from ancestor worship to a weird kind of bird veneration. Attenborough has suggested it was because of a particular bird (sorry, I forget its name) that had the power of staying in the air all the time.

They also got more warlike, battles, overturning of rival group’s statues. Food started running out. It has been suggested that cannibalism arrived.

Of course the Europeans introduced a few more ecological problems, but by that point this civilization was totally broken of it’s own accord.

They’d chopped down all the trees. The raw material for boats (and most mod cons). It seems reasonable to assume that human resources that might have been useful in the field were reallocated to defend or attack.

After a migration from 1000s of miles away, our cousins are now in total isolation. More immediately, their ability to fish was compromised, the range of local flore & fauna had suffered serious species extinction, the whole ecology of the place had been comprised. Broken.

Even without the assistance of the European and his issues, they were doomed.

How stupid could people be?

So imagine you’re from a different planet somewhere out in the galaxy, that despite astronomical odds against, happens to be at a similar level of tech & culture as Earth humans. Looking at the leading denizens of that tiny blue dot and what they get up to – how stupid could people be?

Shaving Horse

Dobbins” (as Raven dubbed it).
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I enjoy woodcarving using a mallet & gouge on the bench, but with that toolkit things tend towards the decorative. But there’s something very appealing about the bodger‘s approach, with minimal tools used outdoors on green wood, generally making functional products. A key tool there is the drawknife, ideally suited for many jobs, but regular bench clamping is really poorly suited to using one.

drawknifeAround the Web are loads of pics of shaving horses, the bench/vice optimized for drawknives. Typically they’re a long low bench with a seat at one end, a rest for the work on the other and a foot-operated lever to hold the work down. I’ve got a fair pile of wood offcuts from various house projects, so decided I’ve have a go at making one. I have promised to make a friend a wooden spoon, so this makes a great Yak Shaving exercise.

oldThere are two general designs, the Continental dumbhead style, as in this engraving , and the possibly more recent English frame style (it’s not illustrated prior to the 19th C unlike the dumbhead for which there are plenty of 15th C pics). I reckoned the frame style would probably be easier to build and also offer more control, so went English.

The design was arrived at by looking at pics of existing horses then mostly doing it by eye, given the wood I had. I made the base a few weeks ago by measuring what felt like a comfortable height and guestimating the kind of reach seemed about right. I angled out the legs about 15°, screwed and glued. At that point I made my first mistake. Before gluing I screwed the legs on to check, unscrewing them splintered off a bit of wood around the holes. Didn’t really affect the structure but was ugly, so after gluing I patched the holes up with filler, making it look worse… Hey ho. Appearance was way down priorities.

Today I added the mechanism, again judging things by eye. The work surface is hinged off the base so:

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This could well be another mistake. I didn’t expect the hinge to receive much force so only used one, but I may well have to add another.

Next I needed to figure out the clamp part. I decided to use a length of 12mm (?) threaded rod for the clamp pivot, so needed to figure out where to put that.

 

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I’ve got an upright drill press but no way could I manoeuvre the thing in position, so I made a vertical guide hole in an offcut and used that to keep the hand drill vertical.

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Bit more trial and erroring got the clamp frame together. The foot rest is screwed to the uprights, but plenty of adjustments for location of the pivot and top cross piece seemed a good idea.

When planning this thing I anticipated having to come up with a way of locking the riser wedge in position under the workpiece support. Overthinking, it seems a loose offcut and friction locks fine.

DSCN6953.JPGAnd so that’s it basically done. I’ll give it a coat of varnish next, then have a play. First impressions are that it works!

Time to mount up.

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(The hat incidentally was an xmas present from Raven’s mum, after she heard I was a fan of McLeod’s Daughters).

Our Area’s Longest Mural?

From London to Longoio (and Lucca and Beyond) Part Two

At first it was just a plain hoarding put around Borgo a Mozzano’s Istituto Comprensivo (an education centre which can comprise, primary, secondary schools, technical colleges and, in Borgo’s case, a fine music school, the ‘M. Salotti’) to fence off a works area. The school needed important structural work done to it to bring it up to scratch with the latest seismic and anti-earthquake regulations. Borgo a Mozzano is in seismic area no 2 which means that quite strong earthquakes could occur (as they have: see my post at https://longoio2.wordpress.com/2015/01/24/what-me-worry/)

Then the istituto’s pupils started painting the hoardings which stretch quite some way around the building yard.

Finally, yesterday the painting work was completed and the boring hoarding had metamorphosed into a very colourful and lively mural – perhaps the longest we’ve seen yet in our area.

Of course, there was a master-mind behind scheme. Ilenia Rosati, born in Pisa…

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Dissecting George the Computer Robot

ge6

Robot George

danbri‘s trying to reverse-engineer Big Trak bots, reminded me I had an old bot to play with : Compurobot® George the Computer Robot from 1984.

Mine was a pressie, long time after that (charity shop?) but pre-Web, didn’t have a manual.

According to The Old Robots Web Site, he has a 4-bit microprocessor.

Curiosity fuelled, last night I opened him up. Two screws by his buttocks, on at the back of his neck, hidden by tape label.

Very neat construction.

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Left, top: two LEDs. Left middle: incandescent bulb.

Right: resistive rubber keypad/board. Speaker, circuit board, battery compartment (1 x PP3, 4 x AA), 2 motors, gears, wheels.

The board’s typical 1980’s, single-sided, pre-surface mount, lots of discretes. I got into electronics at the end of the 70’s, so George’s tech is familiar.

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No sign of his schematic online, boo.

2 chips, 20 3-legged devices – probably transistors (doubt anyone would bother with anything remotely exotic for something like this).

The big chip is marked MP 1342, Google didn’t know it. Presumably the microprocessor (I did find a similarly named brushless motor driver, but pretty sure that’s not the one).

The other chip is a 2212, a 0.5W audio amp. That figures, with the little speaker.

Looking underneath:

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The keypad appears to go directly into the processor, I’m guessing the transistors will be motor & light drivers.

I forget, does the usual complementary pair motor driver need back-EMF protection? I’m looking at the diodes. If not then the trannies are probably set up as Darlingtons or somesuch, they definitely do need a back-wired diode.

Drawn a blank on the processor, but the Old Robots site does have some of the instructions (not full manual) :

Compurobot-z21

So…next steps (time permitting): I think I’ve got batteries, have a play. Find a minimal 4-bit processor emulator, see if I can replicate his functionality.

What would be nice would be to emulate the processor on an Arduino or similar (bit boring coding it up directly), build a George NG. Doable, surely? One day…

—-

PS. I did have batteries, so had a play. Lot of bad contacts there, bit of corrosion around batteries, power switch dodgy. But when power got through, made a hell of an 80’s electronic racket. Enough to scare a cat in Australia (I kid you not).

Still can’t quite make out the button functions properly, but after some fairly random button-pushing he did do some kind of sequence. Different noises, a crunchy effort at running his wheels (WD-40 time), lights flashing.

 

 

 

 

Intense

Damn that was weird.

First, huge apologies to anyone I might have chatted to in the past 18 or so hours, wow, I totally lost it.

I’d had to reduce my medication dose to zero over the space of about 5 days, run out of funds

Check this…

went to dentist a coupla days back. All promising. but the guy handed me a book, Le Macchine e lo Spirito Humano.

wtf?

in my bag had a survey paper on Deep Learning

back of this book, quotes Kurzweil

teeth recoverable, thanks

Small ideas, loosely coupled.

I recently got a little bit worried, spending most of many years advocating a timbl world view, don’t try anything clever with your software.

Damn you, stupid dannys. Just another kind of

foaf:Agent

I assume the schema.org has the same world view. You just cut everything down to a shared notion of communication we can understand. Something like HTTP.

Still true, innit.

Fielding still has a posse.