Using chanter bore measurements!!

[rorybbellows]

These are some bore measurements I found on another thread .How are these actually used when making a chanter ??

B-Pitch Chanter from the bell to the throat and reed seat in inches. Note that the throat diameter is a bit les than 11/64":


Depth Diameter
0 0.4275
0.35 0.422
1.5 0.407
2.95 0.391
4.07 0.375
5.16 0.359
6.4 0.349
7.33 0.328
8.32 0.313
9.25 0.295
10.03 0.279
10.76 0.265
11.5 0.249
12.39 0.234
13.23 0.219
14.19 0.205
15.35 0.188
16.59 0.171
This point would be the throat.
16.975 0.171
17.155 0.188
17.305 0.205
17.445 0.219
17.555 0.234
17.825 0.2635

Tone hole size and placement from bell (D-Pitch nomenclature):

Ghost D 3/16" 2.95"
E 9/64" 4.31"
F# 15/64" 5.55"
G 3/16" 6.88"
A 13/64" 8.98"
B 3/16" 10.56"
C# 11/64" 11.87"
D 3/16" 12.77"

And how were these measurement obtained .


RORY

[billh]

These are some bore measurements I found on another thread .How are these actually used when making a chanter ??...

And how were these measurement obtained .

RORY

You'll have to ask the person who posted the measurements (or better yet, the person who made them). What is the provenance of this chanter anyway?

Such measurements are typically made by measuring the depth of insertion of various gauges of the indicated diameters. Sometimes only round cross-section gauges are used, in which case only the smaller 'axis' of the bore (always somewhat oval, in a real chanter) is measured. Other folks also take measurements with flattened gauges, to try and determine the larger 'axis' of the oval bore. Fortunately the degree of ovality in the best antique chanters is often modest.

I would be reluctant to attempt to use measurements without having some idea about the original instrument from which they came.

There's an article by John Hughes, "A Method of Making Reamers", in SRS v2 I think, which describes a method of making conical D reamers from a set of chanter measurements. You want of course to make a set of reamers that will end up reproducing the original bore as closely as possible. The general assumption is that the original bore can be approximated by "connecting the dots" which represent the bore measurements made by the gauges.

You might have more luck asking about this (and searching) in the uilleannforum "Pipemaking and Reedmaking" forum.

(By the way - that's a very big throat for a B chanter.)

Regards,

Bill

[David Lim]

Are these the measurements posted by B.C.Childress?

David

[John Mulhern]

I think Mr. Childress, when he made the dimensions available, said he didn't measure the chanter throat diameter directly, Rory...so it's almost certainly smaller.

http://chiffboard.mati.ca/viewtopic.php?t=30586&postda ys=0&postorder=asc&start=15&sid=05ac19677ee7123ed 374da395842f91e

Extending the two nearest bore line co-ordinates, D.188 Z15.35 & D.171 Z16.59... and intersecting them with the two nearest reed seat line co-ordinates D.171 Z16.975 & D.188 Z17.155...I plot the throat intersection point as being located at around D.166 Z16.926...but it'd be safest to check with Bruce.

[rorybbellows]

Not to get into the whole Metric/imperial argument ,but talking in thousands of an inch would give me a headache .Metric I think is so much more accurate!!

I dont intend using these measurements its just that I noticed that there does not seem to be a pattern with the incraments.I would have thought that if you were measuring that you would go .eg ,1 inch measure ,2inch measure 3inch measure etc
or are the points that have been measured in the above example some important acoustical points ,or something !!!!


RORY

[billh]

D=.166 or about 4.22 mm is still huge for a B chanter throat.

My guess is that the measurements were made with tools more or less in even "64ths" of an inch, then converted approximately to decimal inches (to three decimal places, i.e. nearest thousandth of an inch).

(1/64 is about 0.156)

Often it comes down to whatever probe sizes are available/handy. If you're making your own probes from scratch then I agree that there are probably better systems for choosing the diameters

Bill