I’ve spent most of today blowing raspberries down a piece of pipe. This is actually what I do for a living, but today it has mostly sounded like that was what I was doing. Normally I’d hope it sounds a bit more like music. Today, it has all been a bit different:

Since the first post on this project, I’ve been making use of all that useless stuff I spent a long time learning once at university. I even got to use some algebra, and re-learned what the value of Pi was on what was apparently Pi day (03.14.15, if you’re using the backwards US date system!).

First of all though, I downloaded Google’s brilliant SketchUp Make software. For those not from the design industry, this was a revolutionary piece of free software which appeared mid way through my degree course and changed everything. Suddenly it became very easy to draw in 3D. For those of us less gifted in complicated CAD software (most of us) it was God-sent. It also saved us lots of money on superglue and foamboard, and didn’t get crushed on the bus on the way in to morning tutorial after another sleepless night of model making.

Using Sketchup, I made a quick wireframe model to work out the geometry and construction of my Lur, then extruded the pipe profiles around it. This is all done at 1:1 scale, and I inserted a bloke into the model to visualise the scale. Sadly I couldn’t find one dressed as a Viking with moveable arms, so the Lur is hovering like a futuristic space-horn. Here is a rough and ready version of that model:

pLur model

Once I had the basic construction worked out, I set about trying to calculate the ratios of pipe section lengths, with all of the radii and relative lengths derived from the length of the tube. This is where the algebra came in! The golden section was used purely for aesthetic reasons, to divide the bottom curve from the top curve at a point which looks balanced. I set this up as a spreadsheet which will calculate all these lengths from simply entering the total length required. Vikings didn’t have computers to calculate these things for them, but it was a satisfying exercise in spreadsheet design nevertheless!

pLur ratios.xlsx

Time then to bring this Lur to life, and to take a hacksaw to some of the pipe lengths I’d bought last week. Again, its been some time since I held a saw but in the space of a lazy Sunday afternoon I’d managed to construct a fairly convincing telescopic conical tube in the pitch of E flat.

Lurs had Trombone sized mouthpieces, which is a problem for me because I struggle to play a mouthpiece that large with any great result. Using a trumpet mouthpiece creates a much cleaner sound, almost like a French horn. We’re after a devastating honk of a tone, which is what the Trombone mouthpiece achieves.

To give a demonstration of my work to-date I borrowed Ian Shepherd to have a honk on my straight Lur in E flat. Ian is a Tuba player (and incidentally a brilliant arranger) and kindly agreed to give a short recital on the Lur:

There is a bit of work to be done on intonation – the fundamental sits nicely in tune, as do the next two harmonics. The third octave is very bright although it can be ‘lipped’ down. Some further experimentation with bell flares and a more tapered leadpipe might help this. Whilst the original doesn’t have these features, it does seem to be slightly better in tune with itself! I wonder also how much the telescopic bore distorts that, but I’ll probably never find out without a set of mandrels.

So I have something which sounds more or less like a Lur, and Ian managed to play along with the piece I was writing. It doesn’t look like much yet, so the the next step will be to bend it into shape. According to Youtube videos, I’ll be needing a hair dryer, some sand, and possibly also a sense of humour.

Another shopping trip it is then. After that – watch this space!

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