Effect of chanter bell thickness on hard bottom D?

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awilde569
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Effect of chanter bell thickness on hard bottom D?

Post by awilde569 » Tue Jan 18, 2011 3:49 pm

I'm working on trying to get a newly made chanter working at the moment, and for the life of me I can't seem to get a hard bottom D on it. I'm wondering specifically if it might be due to not thinning the walls at the very end of the chanter (the bell), but I'm not sure. Making several reeds I've been able to get pretty much all the main notes in tune (excluding ghost D, or D# or Eb as I've seen it called as well). In the few chanter plans I've seen that seemed to be the only major difference, but I couldn't find much reference on whether it was just for aesthetics or served a specific purpose. Any input would be appreciated.
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outofthebox
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Re: Effect of chanter bell thickness on hard bottom D?

Post by outofthebox » Thu Jan 20, 2011 5:57 am

I reckon that the hardness of the D is most likely to depend on the reed. I would try gouging out a little more of the slips from the area above the bridle into the tails, to encourage more 'in and out' movement of the blades. The hard D effect is a product of the sudden change in air pressure when the chanter is lifted off the knee. A constriction - such as a small rolled up piece of card or something similar (I use soft black damp-proofing felt) inserted inside the end of the chanter can also help to emphasise the hard D effect, but it is created by the reed.
Last edited by outofthebox on Thu Jan 27, 2011 5:17 am, edited 2 times in total.

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Re: Effect of chanter bell thickness on hard bottom D?

Post by Mr.Gumby » Thu Jan 20, 2011 8:02 am

The hard D effect is a product of the sudden change in air pressure when the chanter is lifted off the knee.
With a well made reed you can easily drop to hard bottom D from any note in the first octave with the chanter off the knee eg d'-D-c-D-B-D-A-D-G-D-F-D-E-D

Your assumption doesn't explain that or allow for whole phrases and indeed whole tunes played off the knee with hard Ds thrown in.
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Re: Effect of chanter bell thickness on hard bottom D?

Post by outofthebox » Fri Jan 21, 2011 6:14 am

This is true Mr G. Could you post an mp3 as it would make a very good illustration of this phenomenon? I think the critical factor is that the reed must be sufficiently susceptible to changes in air pressure in order to produce the hard D effect - in combination with the subtlety of the piper's bag arm of course.

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Re: Effect of chanter bell thickness on hard bottom D?

Post by dirk the piper » Fri Jan 21, 2011 1:59 pm

If you want to learn how bore changes inside the chanter can affect the bottom D, I suggest you try a couple of experiments. You can roll-up a small piece of paper into a short tube so that it fits against the inside wall of the chanter, and insert it into the bell, effectively making the bore a bit smaller there. Try listening to the tone, and the intonation, and see if it helps you get a hard bottom D. Then try rolling up a similar tube of paper, and place it at the other end, in the throat of the chanter, just below the reed seat. You can also do the same thing by inserting rushes. To rush the throat, you can take a match-stick or an inch-long piece of guitar string, and hang it down from your chanter reed staple, so that the rush hangs down into the throat. Then try the hard bottom D again, and listen for tone and intonation changes again.

I'd be interested in hearing about what you find.

-Dirk
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Re: Effect of chanter bell thickness on hard bottom D?

Post by awilde569 » Fri Jan 21, 2011 5:29 pm

Thanks OotB/Dirk, so far I've found a few problems. A big one turned out to the staple eye opening being too large (on my paki pipes it needed to be considerably larger than this one so far). I did carve down around 16mm length of the bottom end of the chanter to be round and that seemed to help the narrowed staple eye a bit more (though Eb is still a no-go). Second problem (again compared to the paki chanter) was that it wanted a far less rounded "v" scrape, so the first four reeds I made for it were a total bust there (need to work on the reed more, but problem 3 arose). Third problem I've encountered is that the reed cap I first made was a little too narrow inside and kept touching one side or the other of the reed, so that was throwing off notes (that I've remedied today). As far as sticking anything into the end of the chanter, that might be a bit more tricky since it's a square bore :lol:
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Re: Effect of chanter bell thickness on hard bottom D?

Post by outofthebox » Sat Jan 22, 2011 6:57 am

It is best always to avoid the use of offensive terms in your posts. As your signature line states, the intention may not have been malicious on your part, but I'm sure you would not wish to leave yourself open to that charge.

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Re: Effect of chanter bell thickness on hard bottom D?

Post by awilde569 » Sat Jan 22, 2011 7:24 am

I guess I'm a bit confused as to the offending terms in my posts, unless your referring to the signature alone? I would hope that p*ki-pipes were that much of a taboo word :lol:
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Re: Effect of chanter bell thickness on hard bottom D?

Post by outofthebox » Sat Jan 22, 2011 9:34 am

I see that you are in the US and so may not be entirely familiar with the derogatory associations of the term you have used.

http://en.wiktionary.org/wiki/Paki

It would to better to identify the chanter by brand name or maker, as that is normal practice in discussion of instruments here.

Enough said 8) - I'd like to hear some more about your square bore chanter. Did you make it yourself?

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Re: Effect of chanter bell thickness on hard bottom D?

Post by awilde569 » Sat Jan 22, 2011 10:59 am

Ok, given that I can see now where there was a problem and will keep that in mind for the future. To clarify the Pakistani chanter being used for comparison earlier was from Mid East Manufacturing Co.

To answer your question, yes the chanter is one that I've made myself. I based it loosely on the article by Craig Fischer linked on David Daye's website, using measurements based off the volume 1 Sean Reid Society journal for a narrow bore d (albeit setting the sides to the length of the original diameters turned out making it out to be more of a wide-bore in volume and tone-hole sizing). I had mainly went this route since I didn't really have most of the tooling necessary for making the reamers, only the d-bit drills (and not nearly enough of those to try and make a full step-drilled bore style as with a penny chanter by comparison).
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Re: Effect of chanter bell thickness on hard bottom D?

Post by billh » Sun Jan 23, 2011 12:32 pm

I think the wall thickness issue is a red herring.

The (entire) bore, reed, and staple all contribute to the hard bottom D. From your description, there are plenty of things more likely to be major contributors than the thickness of the very "bell" of the chanter.

Much of the bottom D behavior has to do with the tuning of specific resonance peaks with respect to harmonics of the fundamental note D. Since it is very, very hard to actually investigate this quantitatively, one is better off looking first at obvious empirical things such as details of the staple and reed, and at various parts of the bore (of which the bottom section/bell is only one contributor, and probably not the primary one at that).

If you used the narrow-bore D diameters as your side dimensions, you in effect have magnified the bore diameters by sqrt(2), ~1.414. This also has the effect of increasing the cone angle of your chanter. All bets are pretty much off in a case like this, there's no telling what it will act like.

For those of you who are more seasoned pipemakers, it is true that there is a subtle aspect to the wall thickness of the chanter at the bell exit; the shape and width of the resulting "flange" in the bore does influence tuning to a small degree. This means that the chanter wall thickness is not entirely irrelevant, though the effect should be very, very small. As I said, I doubt seriously that it is coming into play in the specific case under discussion.

Bill

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Re: Effect of chanter bell thickness on hard bottom D?

Post by awilde569 » Wed Jan 26, 2011 7:50 pm

Thanks for the input Bill, probably going to work on making up another chanter to try and get it closer to the original here.
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Re: Effect of chanter bell thickness on hard bottom D?

Post by awilde569 » Fri Apr 08, 2011 4:01 pm

Ok, managed to get most of the worts sorted out on the chanter finally... I think... *knocks on wood*

Pictures can be seen at viewtopic.php?f=2&t=3&start=165#p11788

Have a pair of sound clips attached as well, one is just a scale (excluding high c# and top d since those are still being extremely tempermental :x ) and the other is a quick little tune of no particular origin with a set of drones playing. Mind you I'm not much of a player, and had a bad case of butter fingers during these recordings :P
chanter_scale.mp3
A quick scale, excluding high c# and top d
(496.08 KiB) Downloaded 321 times
playing_nothing_inparticular.mp3
Nothing in particular, just a tune played on a whim
(1.15 MiB) Downloaded 329 times
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Re: Effect of chanter bell thickness on hard bottom D?

Post by outofthebox » Sat Apr 09, 2011 7:39 am

Your chanter has an interesting tone - the tuning sounds pretty good to me. Well worth the effort you put into it - and now that you have a model that works the next one should be even better 8)

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