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15 June 2014

Highwayman Banjo - Hooke's Law

Hooke's law clearly states that the force F needed to extend or compress a spring by some distance X is proportional to that distance. That is:F = k X, where k is the constant, "stiffness". Unfortunately, Robert Hooke had nothing to say about building banjos and this is the topic of today's update. Let me tell you what I've been up to...


In Roulette the zero gives the House it's edge. It is neither red nor black, odd nor even. European Roulette is played with a zero. In America the Gaming Houses added a "double-zero" to further tip the odds in their favour. This picture is of the Roulette table on the Pride of Hull, snapped on my recent visit to Amsterdam. Oh yes... I see what you're doing here P&O! Rumbled!


I've done a couple of posts on my banjo pot. You've seen me wrestle with the construction of  a wooden rim. Everything was going swimmingly until I got a comment from +Sven Nyström of Argapa Ukulele fame. Sven questioned my crazy idea of fitting the skin by simply pulling it down over the top of the wooden rim. His biggest concern was that it was going to sound rubbish (my words) with that godawful  thick rim. Surely I was making a huge mistake that I would regret until the end of time?

You know... Sven is right. I kind of knew this at the time, but it took a couple of slaps to the face by Sven for me to start piecing things together. Thank you!

I had been doing all sorts of research into tone rings and I knew that this was where the answer lay. If you have the energy to Google the topic you will find that there is all sorts of black magic being espoused on tone rings. You will find different views on how and why they work and deep religious debates on the best sorts. I decided to keep it simple. See what I bought, above resting on the rim.


Here's a close-up the ring. It took me ages to find one that I thought would fit. If only I'd gone for an 11" head I would have had so many more options! This was shipped over from China and for that reason alone, it put my banjo-building project on hold.

I'm so-so about the quality of the hoop. It has been chromed, but there are a few rough burrs that I'm going to have to sand. The more worrying bit is that it isn't completely round.

The diameter is pretty much exactly what I hoped it would be. The height surprised me: It is taller than I expected. What was I going to do?


With the tone ring on order, I was limited to measuring and dreaming. Oh yes... and I started to build a cajon. Here you can see me imagining how the pot will look with all its jewelery fitted. Hold on a second! Damn! The lugs for the hooks don't reach the rim. That will definitely be a problem! I quickly fell into a black depression. What on earth was I going to do? I imagined all sorts of fun and games having to bend hooks and maybe even adding in some sort of spacers to the lugs. What a bloody disaster!

After a little bit of research I saw a chink of light through the storm-clouds. Not all hooks are created equal. The top of the hook can be shaped to fit different styles of  tension hoop. It looked like mine were angled to fit a thin-style hoop. But my tension hoop is round! On the off-chance I might be able to improve things, I ordered some round hooks. It was worth a try...


Talking of shit and disaster... Do you remember me talking about my "magic" 21st fret? I'd toyed with the idea of signing my banjo here. See in this picture that moment where I realise that due to the wider-than-anticipated-head, that I'm going to end up having to cut into the 21st fret when I fit the neck! Oh well... it might look quite good when it's done! ;-P

If anyone asks... this was the way I planned it.


Whilst I was digging through all my building crap the other day, I found some nylon banjo strings that I'd bought some time in the dim and distant past. I cant even remember when I bought them. They're a set of Chris Sands "Classic" nylon banjo strings. They're medium gauge and made in the UK, "guaranteed manufactured from the finest quality materials and to be the correct gauge." Having finally got down to 3 strings on my Windsor Whirle, I figured that now was the time for a new set. I like the idea of nylon as I suffer from sweaty paws, but I worried about losing the classic banjo sound.

I can report that the banjo doesn't have the same twang to it, and it does play quieter, but actually, the sound isn't all that bad. I'm happy! As a side-note: I was a bit disappointed to find that the 4th string is metal. That's false advertising that is! ;-)



I'm not sure of the official way to fit a tone ring of the sort I have, but I'm suspicious that it involves just placing it loose and letting the skin hold it in place. I'm sure that there will be someone somewhere claiming that this gives the best acoustic sound by magically letting sound waves escape underneath.

I don't believe in magic.

I decided to cut a groove for mine to sit in. My thinking is that it will hold it in place, will force it round, and it will reduce the height a bit. See here how I've had to make a jig so that I can route a circular groove. I don't know how I did it, but the groove is perfect!


Here's a shot of the tone-ring fitted. It took me ages to get the jig sorted and everything lined up. I still can't believe that I managed to pull this off! What I've discovered is that the height of tone ring means that I don't need to touch the rim any further; the skin stands proud. For the moment, my intention is to leave it thicker at the top.


And here's the pot with tone ring fitted... and trimmed to size. I do hope I haven't cut it too short. It will be tight, but I want it to be as thin as I can get away with. What do you reckon? 60 or 500 hooks? :-D

The eagle-eyed on Google+ will know that I've started work on the neck. I'll give you an update on that on another day. Next weekend I'll be off to the Ukulele Festival of Great Britain in Cheltenham. I'll try and bring back some photos for you. If you're going then be sure to tap me on the shoulder... I'll be the one wearing a beard.


I love sport as much as the next man. Okay... so England can't beat Italy. I'm over it! Here's my tribute to the World Cup in a tiny sound-bite of an idea for a potential up-coming song. Olé, Olé, Olé, Olé...

:-D

2 comments:

  1. Uh-oh, I feel I might be a bad influence. There'll be no stopping your building endeavors now! Welcome to the dark side.

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    Replies
    1. Ha ha! Not a bad influence at all! I appreciate your timely words of wisdom. Thank you!

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