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Anyone know how to undercut?

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Anyone know how to undercut? Empty Anyone know how to undercut?

Post  Bob Salter Mon Dec 13, 2010 2:39 pm

Can anyone here explain how to 'voice; a chanter? I know it involves undercutting the toneholes and I also know that you have to start at the top as each undercut affects all the notes below it. I want to know how to add tone colour to my uilleann pipe chanters. The question was asked on one of the other forums but it looks like its going to get ugly there so I thought Id ask a friendlier crowd. I know Geoff woofe wrote a couple of articles about it in Ceol na hÉirreann vols 1 and 2, but have no clue where to find them Rolling Eyes Does David quinn cover it on his CD, its about time I bought that.

Bob
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Post  Yuri Mon Dec 13, 2010 6:41 pm

Bob, it's the other way round. Any one hole changed will affect one or two holes above it. So if you sharpen the lowest hole, it will also slightly sharpen the next one up, and to a slighter degree, the next one up, too. Always start from the bottom and work your way up. (By the time you got to te top, if there was a lot of hole enlarging to do, the overall pitch might have dropped by a few cents. In extreme cases you might need to start again, but this time it should be just minimal.)
And it's not necessarily undercutting. You can enlarge holes all the way round.
But in any case, it works by having a very slender knife that you can stick into a fingerhole without it touching the sides, and carve away a sliver from the inner rim of the hole. You can also use a Dremel or similar, with a spherical or inverted conical cutter that will go in the hole, then cut away the iside rim.
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Post  MichaelLoos Mon Dec 13, 2010 11:43 pm

Thze UP chanter is a closed chanter, therefore undercutting a tonehole has an effect on both the tones above and the tones below. Starting from the bottom is the better way, but you should be prepared to go twice through at least, being careful of leaving enough reserve for surprises... a tone can rise in pitch considerably from undercutting another hole.
Undercutting towards the reed end of the chanter will raise the lower octave tones more than the high octave, undercutting towards the bottom end will have more influence on the second octave and may even (to a small amount) lower the pitch of the first octave tone.
Generally, as Mr Gumby pointed out correctly in the other forum, undercutting reduces turbulence in the bore, and on many woodwinds, it is generally done to every tonehole to add brilliance and response. Whether or not this is desirable for an UP chanter, is mostly a question of taste - keeping in mind that many details of construction lead to an intended loss of harmonics (the cutoff of the cone, the wall thickness, the large reed). We call it soft, other wind instrumentalists might call it dull... Therefore a pipemaker will have to make up his mind what type of sound he wants for his instruments, and then decide if he wants to use (generous) undercutting as a means of voicing, or scarce undercutting only as a means of tuning and getting the two octaves together.
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Post  Bob Salter Tue Dec 14, 2010 10:52 am

Thank you everyone for the help. I certainly have plenty to think about now. Michael, could I produce a bright sounding chanter like the one in the vid I sent you by rounding off the inside of toneholes? (for anyone interested Ive posted the pipe sound Im trying to emulate in the youtube section under Bon Lavogue)

Bob
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Post  Art Sun Jan 02, 2011 2:01 am

Do professional pipemakers have a way to regularize undercutting? What's behind my question is this: if you have a solid design for a chanter, wouldn't you want to repeat the same exact design each time? I'd think that undercutting would be very difficult to do the same each time. Is that right? Or is undercutting a way of compensating for inevitable differences in individual chanters?
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Post  texasbagpiper Wed Jan 05, 2011 1:09 am

I won't repeat the above, because Yuri and Michael gave good sound advise.

I use a small round, rod file. The file is about 1/8" round. You can also use a dremel, but it takes material off quick so you have to be careful. You can also move the tone hole up a bit on the next chanter you build, but note down any changes it may make to other notes that use the same tone hole in combination. Once you have your design dialed in, you may not need any undercutting unless you have incorporated it into your design. I do not use any undercutting, for the most part, in my UP chanter design. While undercutting, its always a good idea to test the chanter in question with more than one reed. If your using a tuner, write down your results +- cents. Also, use the same reeds when you build your next prototype and start moving tone holes, sizes, etc. Seth
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Post  Yuri Wed Jan 05, 2011 4:55 pm

I forgot to mention a very important point. If using a Dremel (or similar) never use cutting bits. It's strictly diamond ones, at least for smaller fingerholes. They don't cut into the wood too much at once, it is more like gradual sanding away. With truly large fingerholes I have used cutters, but as often as not tended to overdo it, so be careful.
And as to the standard stuff. Weeell, yeah, it would be all true. In theory. The whole point is that in theory all reeds are exactly te same, all wood coming out at the end of the process is exactly the same, and it also will behave later in exactly the same manner, too. We all know that this rosy theory is just that. In reality if you want a well tuned chanter, you have to tune it to the reed. Also to the bag. Also to the stock. I just happened (for a reason) to stick a chanter from one bag into another (to tune a new drone to), and surprise, surprise, it is out of tune. Not terribly, but still. Back in its own bag it's perfect. So, to sum up, if everything is exactly the same, then, yes there is a very good reason to manufacture everything to very strict specifications, keeping all standard. Otherwise, in real life (at least for the individual craftsman) it's more rewarding to actually tune things individually. Even the best GHB makers face this problem, admittedly to a much smaller degree. This last is, of course, the result of a truly industrial precision approach of the big makers, where they really can keep things standard (up to a point, still.)
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