NPU Coyne B chanter problem

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Richard Evans
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NPU Coyne B chanter problem

Post by Richard Evans » Fri Sep 20, 2013 2:35 am

I've built a chanter according to the NPU Coyne B dimensions. I have a couple of reeds built to the dimensions supplied by Bill Haneman, but I'm pretty much a beginner at setting chanters up, and at reed making.

From low G upwards the performance is certainly acceptable, nice tone and reasonable tuning. However, F# is very sharp, about 40 cents from where it should be, and low E is grossly out, almost a semitone sharp. This is the same with both reeds. Hard/soft D are both OK.

Any ideas where to look for the problem? I have checked the bore with rods, it's not perfect but each rod goes within 3-4mm of where it should be so I don't think that should cause gross problems, maybe a small discrepancy.

Thanks
Richard

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awilde569
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Re: NPU Coyne B chanter problem

Post by awilde569 » Fri Sep 20, 2013 8:53 am

The tolerances of the cone probably need to be kept a bit more precise if you want to use the listed dimensions for tone hole sizing and placement. If it were a cylindrical bore then it would be far more forgiving, but being a tapered cone if that taper changes the tonehole placement may change or simply not work at all across octaves depending (It can probably be safely said that it's as much an art as is it a science). With the parabolic bore whistles that I make if I don't get the taper reamed correctly in the head section then it winds up throwing the upper octave notes all over the place, and that only has a small section which is tapered not the entire length. Just some thoughts.
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PJ
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Re: NPU Coyne B chanter problem

Post by PJ » Fri Sep 20, 2013 9:41 am

Before messing with the chanter itself, have a go at adjusting the reeds.

What sort of bridle are you using on the reed? I find that a thin wire bridle placed half-way up the V (as Andreas Rogge prefers) gives more control than a copper collar at the base of the V. Try different types and positions for the bridle.

If that doesn't work, when a reed plays too sharp on certain notes in the lower octave, my instinct is that the cane is too thick at the critical point (for those notes).

If you have already made a bunch of reeds, and they all have the same problems with E and F#, try scraping different parts of the V and see if that improves the tuning. Again, my instinct would be to scrape the middle of the V, rather than the top (lips) or bottom.

Welcome to the world of conical bores!!
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Re: NPU Coyne B chanter problem

Post by outofthebox » Sat Sep 21, 2013 5:59 am

You could also try experimenting with different staples - but if F# and E are playing very sharp in both octaves then it seems most likely that the bore/tone hole size is the problem. You might be able to test this out by partially blocking the F# and E open holes with tape - or constricting the lower half of the bore with something like folded card that you can slide up or down - and see what happens on your tuner.

Richard Evans
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Re: NPU Coyne B chanter problem

Post by Richard Evans » Sat Sep 21, 2013 3:39 pm

Thanks to all for the suggestions. I think it's a reed issue- the bore is really pretty accurate I think and the second octave is fine. Rushing the bottom few inches has no significant effect. Tone holes are accurately placed, one or two are a few thou small but can always be enlarged. Taping the E hole kills the low E dead- it's already pretty small of course. Hard E is actually a good strong note at reasonably acceptable pitch.
I think another batch of reeds is called for.
Cheers
Richard

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Re: NPU Coyne B chanter problem

Post by MHay » Fri Sep 27, 2013 7:09 am

What dimension did you use for the eye of the staple? I've found an oversized eye ID can sometimes cause that type of problem.

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Re: NPU Coyne B chanter problem

Post by Richard Evans » Mon Sep 30, 2013 2:53 pm

MHay wrote:What dimension did you use for the eye of the staple? I've found an oversized eye ID can sometimes cause that type of problem.
1.2mm. This is a dimension not given in the otherwise detailed description, so I followed the measurement suggested in Dave Hegarty's book. I also note he has an alternative suggestion of 1.0mm so I'll investigate when I have time.

Cheers
Richard

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Re: NPU Coyne B chanter problem

Post by tompipes » Tue Oct 01, 2013 9:02 pm

Richard,
You might find some useful info here http://seanreidsociety.org/SRSJ1/South% ... 0hoard.PDF

and here http://seanreidsociety.org/SRSJ1/Recons ... 0reeds.PDF

All the best,

Tommy

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Re: NPU Coyne B chanter problem

Post by Richard Evans » Wed Oct 23, 2013 6:24 am

Thanks Tommy. The second doc. has dimensions for a reed for this chanter quite a bit different from the figures Bill H quotes, and I've had more luck with these measurements.
Anybody else making one of these chanters?

Cheers
Richard

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Re: NPU Coyne B chanter problem

Post by SeamusRua » Thu Dec 31, 2015 6:04 pm

I recently made a chanter based on these plans and it wasn't working very well at all until I rounded the inner edges(the outside edges had already been appreciably rounded, but my first attempts to round the inner edges were pretty much unsuccessful) of all the toneholes. Before rounding the effectively rounding the inner edges, the tone wasn't very good, worsening progressively going down the chanter(which makes sense due to the dampening properties of the sharp edges) and the low octave, close-fingered e was barely playing at all, rather giving an airy hissing. Rounding the tone hole edges has greatly improved the tone and response, especially of the lower notes. The first octave, on-the-knee e is now playing, although is somewhat sharp(while the off-the-knee e is in tune). This seems to me to probably be due to the influence the secondary, passive standing wave below the e holes as Bill Haneman went over in another discussion on this forum(viewtopic.php?f=4&t=1695). I'm a little unclear as to how these concepts apply to notes with multiple fingers open, however, if I have the right idea, enlarging one of the bottom two holes, possibly the ghost d/eflat hole(as this wouldn't affect the off-the-knee e), might reduce the influence of the secondary standing wave which is sharpening the note. I would probably enlarge the hole to the sides. Anyone have any thoughts on these hole adjustments?

Also, as far as reeds go I've made quite a few reeds which are loosely based on the measurements of those here(particularly reeds #1-7)which are working pretty well: http://www.seanreidsociety.org/SRSJ1/So ... 0hoard.PDF
These seem to be working much better for me than those I made based on the measurements from the reconstructing chanter reeds article(not to say that they absolutely wouldn't work). The main problem I had with the reeds based on the second source was that they played very flat of where I would expect this chanter to play(About 30 cents flat of modern b is what I've been expecting from this chanter.)

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Re: NPU Coyne B chanter problem

Post by billh » Thu Jan 28, 2016 12:11 pm

Richard: the dimensions given in the 'Reconstructing Chanter Reeds' article are intended for use with a sizeable rush. The others are not.

Most people's initial mistake with chanters like this is to make the reeds too hard or stiff.

SeamusRua's observations sound about right to me. On some notes, vigorous undercutting may be in order.

One thing I have recently found (thanks to Makoto Nakatsui) is that reverse tapered staples work surprisingly well in this bore, with better tuning that the same staple placed 'the other way round'. In particular the F#s octave is less wide, and the high B is not sharp.

Best regards,

B

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Re: NPU Coyne B chanter problem

Post by SeamusRua » Thu Jan 28, 2016 2:11 pm

Bill,
looking both at your reed dimensions on your webpage and those included in the Hannon Coyne document, I was wondering if you gouge out the tails on your reeds as it seems this would have a significant affect on the pitch of the reed. Also from your dimensions it seems that you use the same reed design for all narrow bore chanters of various pitches, from c sharp to b flat. Is this a correct presumption?

SeamusRua
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Re: NPU Coyne B chanter problem

Post by SeamusRua » Thu Jan 28, 2016 2:18 pm

Also, regarding the tuning issue with the Es, slightly more rounding of the tone holes' edges corrected the tuning. Slightly more rounding of all the holes has further improved clarity and especially the chanter's responsiveness to cross fingerings. I found that this rounding(not scalloping) of the outer edges of the holes had a surprisingly strong affect on the tone improvement as well.

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Re: NPU Coyne B chanter problem

Post by billh » Thu Jan 28, 2016 2:19 pm

I start with the same staple and slip dimensions. I may make small adjustments as I go, depending on the chanter, but often find that I can literally swap reeds between pitches to good effect. Generally B flat seems to like a slightly wider reed, say 11.0 mm rather than 10.5-10.7. But yes, B and C# usually like the same reed.

I don't gouge the tails of my narrow bore reeds, but if the cane is stiff I may scrape them a bit thinner where the tail meets the head section.

Rounding all edges of the toneholes is vital, as you are discovering.

SeamusRua
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Re: NPU Coyne B chanter problem

Post by SeamusRua » Thu Jan 28, 2016 2:23 pm

Thanks for the replies Bill.
Just wanted to say your posts on this forum have been very helpful.

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