Posted by jerry on September 29th, 2004 — Posted in Music, Woodwork
I was giving some thought the other day to how best to put together an online course in fiddle playing. But I am easily distracted, and out of idle curiosity started searching for instructions for making a violin – preferably in as few steps as possible and in the simplest manner possible. But this is a violin we are talking about – they aren’t meant to be easy are they? Well, structurally we are just talking about a box with a handle on it… Anyhow, I encountered Derek Roberts’ site devoted to detailed instructions on making a violin in 24 days – or at least 24 episodes. It is beautifully structured and well illustrated. Even if you are not thinking of making a fiddle – the site will give great insight into what goes into making up a violin. He starts with selecting the wood, and goes from there. It has full marks from my point of view – and I’ll be adding a link from my band’s web site. After all, if you are thinking of doing an online course in fiddle playing, you’d better think about getting yourself a fiddle! Highly recommended 🙂
cheers
Jerry
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Posted by jerry on September 27th, 2004 — Posted in DIY, Technology, Woodwork
A while ago I made a primitive electric motor using instructions from an old school science book – My excuse was that I wanted my then pre-teen daughter to see how they worked, but really it was as much for my own satisfaction and fun 😉
The one I made used a large bolt (with corresponding nut and washers at each end for balance) which was inserted transversely through a pre-drilled hole in a cylinder of wood. The axis of the cylinder had a couple of nails inserted as axles – and the rotor assembly was supported on thick wire supports. I wound a fairly long length of insulated wire around the bolt and set up two electromagnets made the same way and lined up with the head and nut of the bolt. I used a couple of pieces of tin can tacked to the wooden shaft as contacts for the brushes (which were themselves made from the springy tin cut from a tin can and sanded to make a good contact surface. There were not that many windings so it took four of the big square ‘dolphin torch’ batteries to make it go – but it worked – to the amazement of my neighbour 🙂
A slightly similar (and simpler) one can be found at this site – their motor looks like this:
and they give instructions for making it.
Today, doing a bit of surfing I came across a web site with images of a wide range of early electric motors and their precursors – some fascinating devices! I loved the magnetic beam engine…
Enjoy!
Cheers
Jerry
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Posted by jerry on September 26th, 2004 — Posted in Woodwork
I read about a great finishing technique in Fine Woodworking magazine – it involved treating the varnish as though it were French polish. Now I’ve never been really great at applying smooth finishes – I usually wind up rushing things and putting on too thick a layer of polyurathane varnish and then trying to sand back runs and making a general mess of things.
This week a friend came over bearing an unfinished wooden box, and asking very very nicely if I could just make a small lid insert and slap on a coat of varnish. Obviously she had never seen any of my finished work or she might have looked elsewhere.
I did have some 3mm MDF for the insert and was able to cut it accurately but the finish was the daunting part. Now, I have in the past been able to get a slight french accent on my polish, if not actually achieve the essence of french polish.
Enter Fine Woodworking… the box was assembled, but as yet had no hinges or catches – a good thing – but it was just in roughly dressed timber and still had quite a rough surface. So I set to work with 300 grit sandpaper on my triton orbital sanding attachment, and gave all six surfaces a bit of a going over, then went to a couple of finer grades up to 1500 grit until the surface felt like talc. Then making sure all my brushes were locked away, I cut up some chux superwipes into thirds and folded them over to make a pad, and using a small amount of Wattyl Estapol Gloss I rubbed the gloss varnish into the timber as though it were shellac dissolved in spirit – and voila! one of the best smoothest finishes I have achieved so far!
I reckon the box should be finished and assembled by about Wednesday – more then!
Addendum: And here is the completed box
The embroidery is by Annie Whitsed
Cheers
Jerry
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Posted by jerry on September 25th, 2004 — Posted in DIY, Journal, Woodwork
Well, I’m not likely to get me welder’s certificate anytime soon!
At least I was able to strike an arc and this time I didn’t just burn a hole through the metal like I did the last time I tried. I was able to actually lay down some metal on the mild steel plate – though it was a bit haphazard. you see, the arc is so bright you need to wear this really really dark shade on the protective helmet to avoid eye damage.
Thing is you can’t see a thing when the shade is down. I tried it outside and could see a faint outline of the table where I was meant to be working, but there was too much light coming in from behind the helmet. So back into the garage I went. There I set up a couple of the band’s spotlights shining directly onto the work – that did the trick!
Now I just need to be able to keep the arc going for a while so it builds up a continuous bead of weld metal. Maybe I’ll have better luck tomorrow….
I did manage to find a good web site for the amateur welder though – just click the link 🙂
Cheers
Jerry
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Posted by jerry on September 24th, 2004 — Posted in Music
Some 3400 year old ancient Ugaritic tablets from what is now Syria revealed a complete song deciphered by Prof Kilmer from University of California. The thing is there were twice as many notes as word syllables, but when the notes were matched to the syllables, they doubled up into logical harmonies, suggesting that this hymn was sung in polyphonic parts. A corollary to this is that the scale was actually a diatonic scale – like our present day ‘major’ scale – one of many modes (like major, minor, myxolidian, dorian etc). However there are many musicologists who think that the diatonic scale was only invented by the ancient Greeks about 2000 years ago.
click on the image to take you to the site – and if you click this image there you will be able to hear a midi file of the ancient song.
Of course, anyone who has heard Fijians or Papua New Guineans singing would recognise immediately that you don’t have to be musically literate to sing complex harmonies. Robert Fink wrote a book in 1970 called “The Origin of Music” in which he articulated the view that there is a natural foundation to the diatonic scale – a view that has actually been around for a while, and is readily discernable to any fretless stringed instrument player. I first heard about it in 1984, while listening to some radio lectures by a musicologist that my recollection suggests was Robert Haas, that the diatonic scale is what happens when you take the main three musical harmonic overtones, build on their overtones and arrange them in linear sequence.
The human ear is quite amazing – and childrens’ ears are able to distinguish most of the overtones without difficulty. It works like this:
If you take a string, say one tuned to the note ‘C’ and play it, you will get not only that note, but a whole series of other notes that make up its harmonics – these are the overtone series. The first of these is derived from the string being halved which yields the octave above the note – so it is another ‘C’. This is the strongest reinforcement of the note, so it is the most readily discernable and gives strength to the note. The next occurs at the one third point, and this generates a note a fifth above the tonic (the note ‘G’) – this is called the ‘dominant’ and it is the first different note to be heard. the next occurs at the one quarter point and yields a note a fourth above the dominant – it is another octave ‘C’ – so it still reinforces the tonic note.
Now it gets interesting… the next overtone is where the string is divided into fifths, yielding a note a third above the tonic – this is called the ‘sub-dominant’ – the note ‘E’, as it is strong but not as strong as the dominant. The next harmonic divides the string into sixths, making a note a third above the E which is another ‘G’ – now we start to see a pattern. By this time the tonic note – ‘C’ has been reinforced three times, while the dominant has been reinforced twice and the sub-dominant once.
The next overtone on our C string is where the string is divided into sevenths, yielding now a ‘B-flat’. As the string is divided into eighths we get another ‘C’ which again reinforces the tonic note.
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But now we notice a wonderful thing. Have you heard children taunting each other? have you heard them chanting ‘Nyah, nah, ni nyah nah…’ Why is this a taunting tune the world over? And why is this remarkable? Look at the harmonic overtones that are not the tonic note, and look at the first three without repetitions – play them if you have an instrument to hand. The notes will be: G down to E, then up to B-flat. Try playing G,E,G,E,G,E,B-flat,G and hear that taunting tune. Think for a moment about the sophistication of children’s ears to pick up the first four harmonics and then recognise that they can represent weakness by singing or chanting the first three overtones that do not reinforce the tonic note!
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Are we amazed yet? there’s more.
Let’s continue the arithmetic progression up the harmonics. The next in the series is where the string is divided into ninths – this gives us a ‘D’ or supertonic as it is one whole tone above the tonic note. Divide the string into tenths and we get an ‘E’ which reinforces the earlier E – with all this reinforcement, that is why a Major chord based on C will be C,E,G – as these most strongly reinforce the note – any other combination will sound weaker, because there will be interference as weaker harmonics are being emphasised – hence a minor chord sounds weaker or even a little sad, as against the strong happy sound of a major chord.
back to our progression – the next overtone divides the string into elevenths giving us an F-sharp. Finally, with the twelfth harmonic, we get another ‘G’. We have seen that some notes keep getting reinforced, and others don’t.
Fink points out that the most audible overtones have some simple ratios – 2:1 for the octave, 2:3 for the fifth (or dominant), and the fourth note of the scale (whose first different overtone is the octave) with a ratio of 3:4. If we draw out the first three different overtones of these three notes and lay them out in sequence, we get: voila! a major scale.
He goes on to explain how some of the other types of scale came into existence, but for me the interesting thing is that the scale is based on the sheer physics of sound – and that our ears are perceptive enough to pick out natural harmonies.
Cheers
Jerry
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