Making Plastic Chanter Reeds
by Jon Swayne
These reeds were developed for the English Border bagpipes I make. They would not necessarily suit a chanter of different design, though the methods and principles may be useful elsewhere, and the dimensions can be changed as appropriate. The dimensions initially given here are for a chanter in G; dimensions are given at the end for A and low D. Note that I also use the reed of G dimensions (with no modification other than final finishing) in my highland fingering lowland chanter in A.
- Mandrel made from a piece of 8mm tool steel about 150mm long; turn one end to a taper to fit inside of staple; file tapering ‘flats’ 20mm long symmetrically on opposing sides of the tip, ending up with a slightly ovalised shape to the tip, the minor axis measuring about 1mm. See attached sketch. Alternatively you can buy an oboe reed mandrel from woodwind suppliers, and modify it as above.
- Small vice A swivel vice which clamps to your bench or table is ideal.
- Sharp knife (e.g. Stanley)
- Long-nose pliers preferably with flat, smooth jaws
- Burnisher (6mm shank screwdriver will do)
- Small hard wood block with very smooth surface; the ideal is end-grain box, 50mm diameter, or 50mm square, 20 – 25mm thick.
- Reed blade shaping tool see note below.
- Abrasive Paper (optional) 320 and 500 grit, lubricated silicon carbide. See below.
- Plastic pot for the reed blades: It is not very useful to specify a particular brand, since they are changing all the time. You just have to find one which suits you and hope that the manufacturer does not change the design too soon. Yoghurt, fromage frais and crme fraiche pots usually yield the best material. Food pots range from very soft to quite brittle. Choose one which is not too extreme. It should respond well to scraping and sanding; not all do. The diameter is important because it controls the degree of opening of the lips of reed; about 100mm seems best. Thickness should be around 0.35mm. Prepare the pot by slicing off the bottom by cutting with the knife round the bottom corner. Make a single cut from top to bottom with scissors so as to open the cylinder. Again with scissors reduce the height of the open cylinder to 35mm, removing material from the top or the bottom, or both, so that the remaining material is of relatively even thickness. If you can detect a taper across the height of the cylinder, regard the thin end as for the lips of the reed, and vice versa. From this cut blanks about 25mm wide. You should have now a dozen or so blanks.
- Staples: standard oboe staples, cork removed and reduced in length to 31mm by cutting off the wide end. See notes.
- Waxed thread: best diameter is 0.5mm or slightly above. You could use the same yellow hemp as you use for your drone sliders, or get suitable reed making thread from woodwind suppliers. You can wax a length as you go by rubbing with a small block of beeswax, or you can immerse a spool of thread in hot melted beeswax. Once you think it has absorbed as much as it will, take it out, drain and cool. Dont get the wax too hot, especially if the thread or spool is plastic, because they may melt.
- PTFE tape: (white plumbers tape).
1. Prepare a staple by placing it on the mandrel. Flatten the end to conform to the flats filed on the mandrel by squeezing between the jaws of long-nose, smooth-jaw pliers. You can form a nice ‘eye’ with a burnisher (or any smooth steel rod) by stroking towards the tip.
2. Take a plastic blank, and cut it down the centre along the length, making two blanks. Cut each one to exactly the same trapezoidal shape, 10mm wide at the lip end and 3.5mm at the other, 35mm long. If you are making a lot of reeds, a shaping guide is useful. See note below. To get consistent results you need to be precise about the shape. You may find it interesting to experiment with very small changes and note the result.
3. Temporarily secure the blades together (concave surfaces facing) by folding a small square of 19mm masking tape across the lips or you can bind with a few turns of waxed thread.
4. Position the vice on right hand end of the bench (if you are right-handed), or if it is a swivel vice, place it anywhere but angle it at 45 degrees; this is so that your hand does not hit the bench when winding on the thread. Place the mandrel in the vice, with flats above and below.
5. Place a prepared staple onto the mandrel, and slip the blades onto the staple. Using the free end of your reel of thread, secure them with a clove hitch round the tails. Adjust the position of the blades on the staple so that the tails are 13mm from the large end of the staple. Bind with firm, close turns of thread so that the edge of the last turn comes 34mm from the large end of the staple.
Make the last turn a half hitch. Wind back to the start with two or three wide turns, and finish off with two half hitches.
Wind thread onto the bare end of the staple to suit the reed socket in the chanter. Start from the bottom of the blades, trapping the end of the thread with the first few turns, wind to within 0.5mm of the end; back to the start with one turn, then close turns for two thirds of the way to the open end, back again to the start in one turn, then back in close turns for one third and finish with a half hitch. The fit of the reed in the socket should be such that the end of the staple is just held out of contact with the wall of the socket.
Remove the mandrel from the vice. Cover the binding with a few turns of PTFE tape. Start from the blade end; make a couple of turns there, just covering the end of the binding, then a few diagonal turns towards the tails; make a couple of turns above the socket binding; pull the tape to break it, and rub it down with the fingers.
6. It is necessary to give the blades a little more arch in the throat area. Do this by squeezing across the width in the middle of the binding; a fair amount of force may be required if the plastic is on the thick side. The sides of the blades may open slightly. You may observe a very slight ridge or spine. Then squeeze in the opposite direction to restore the shape of the reed. The sides should be closed, but there should be a visibly greater curve in the centre of the blades above the binding. This area can be closed further (or opened) by gentle pressure to adjust the response later on.
7. The reed is finished by scraping with a very sharp knife. A new heavy duty stanley knife is adequate, though a slightly curved (convex) blade is better as it can be used more selectively. First trim any excess off the tip by reducing the overall length of the reed/staple to 46mm; lay the reed flat on the cutting block and make a vertical cut over the whole width of the tip at once.
The degree of scraping required depends entirely upon the quality and thickness of the plastic, and the required response. It is impossible to say how many scraping strokes should be made, because it depends upon how much material is removed at each stroke. If you are used to scraping cane, with plastic you should be removing much less at each stroke. Don’t try to remove too much at each stroke. Attempt a mean between skating over the surface and digging in. You can make some diagonal strokes working towards each tip.
Start by scraping very lightly all over, to remove the printing and surface gloss. Then the objective is to lower the resonance of the reed by scraping until the reed gives the correct response in the chanter. Start with 5 or 6 strokes from just above the binding towards the tip. The scrape will be mainly in the centre of the blade at the binding, but across the full width at the tip. Work progressively towards the tip, finally working on the last 2-3mm. Continue until the tuning, response and sound quality is correct. It may be necessary to raise the pitch of the reed by clipping the tip. Don’t take off more than about 0.25mm at once. Its best not to reduce the overall length of the reed below 45mm, but all will depend on the thickness and stiffness of the plastic. Remember that you can also alter the response of the reed at this point, by adjustments in the degree of opening at the top of the binding. Most often the reed will need closing here, which reduces playing pressure, and improves overblowing. It can also make low G more pressure sensitive, but this can be rectified by further scraping.
8. 500 grit silicon carbide paper is useful for refining the tips of the blades. Hold the staple between thumb and fourth finger, pressing the tips of the blades onto the paper with the tip of the index finger. Aim to treat only the last 4mm or so. Adjust downward pressure and the amount by which the end of the staple is raised accordingly.
9. You can finish entirely by using sandpaper alone. If you prefer this method, I suggest you use a lubricated silicon carbide paper (such as 3M Trimite Frecut) no coarser than 320 grit.
A small rectangle 80 x 40 mm on a wood block is convenient. Hold the reed as above and rub in a shallow eliptical motion about 3040 mm wide making not more than 10 strokes or so on each side before testing.
Dimensions for chanters in A
1. Staple length, 30mm.
2. Distance from large end of staple to blade tails, 12mm.
3. Finished blade length will be slightly less.
Dimensions for chanters in D
Staple length, 40mm.
Blade Shape: initial length 44, tip width 10.5, tail width 4.
Binding on: distance of tails from open end of staple, 15mm. Binding up to 44mm from open end of staple.
Overall finished length, about 57mm.
Blade shaping guide
Take a pair of long nose pliers.
Grind out between the jaws to take a pair of pieces of metal with the same dimensions as the reed blades (but slightly longer at the wide end), and having the same curvature. Braze one piece to each jaw (curves matching rather than opposing), in such a position that when the pliers are closed, a blank is held firmly overall. A sharp blade along the edge of the metal inserts then cuts the blank to shape. A small snap-off blade knife is convenient for this. Keep your scraping knife just for scraping.
These are available in quantity from Guercio, Wombacherstr 65, 97816 Lohr-Wombach, Germany.
Windcraft Ltd, Tel: 01628 778 377
Wind Plus Ltd, 2 Southfield Close, Scraptoft,
Leicester LE7 9UR, Tel: 0116 243 1698
Howarth of London, 31-35 Chiltern Street, London W1U 7PN, Tel: 020 7935 2407
Notes on tuning
If you want to stand a chance of playing in tune with others, especially pipers, you need to make sure that your pipes are tuned to the correct standard. This is usually specified as A=440Hz at 20C/68F.
The reason for including temperature in this procedure is that pitch in wind instruments is affected by the speed of sound, which in turn is affected by the temperature of the air (and humidity, and air pressurebut there is only so far it is worth going; humidity you might need take into account if it is extreme). The pitch variation is approximately 1% per 5.5C or 10F. So at 22C you should allow for your pipes to play nearly 7 cents sharp, and at 28you are up to 25 cents, or a quarter of a semi-tone. Of course my workshop is rarely at exactly 20C, so I keep a thermometer and temperature compensation chart (see below) over my bench, and calibrate my tuner accordingly.
I use my tuner in electronic drone mode, operated by a footswitch, as a rough guide when first testing reeds, then when making final adjustments I make sure the drones are perfectly tuned to the tuner, and test the reed in the instrument.
Thus the tuner, and therefore the drones will be tuned to a G which is an equal temperament G below A=440Hz, adjusted for temperature. In case you think of tuning the chanter scale against the tuner, using the tuner in its listening mode, remember that the chanter scale is a just scale not an equal temperament one. See chart below; this is included for interest and information. The only tools needed for tuning the chanter against the drone(s) are the ears.
That the chanter scale is a just scale needs slight qualification. Because F natural at the top of the scale is a cross-fingered note, the tuning of both this note and F# is determined mainly by the size of the top finger hole. If F natural is made just, then F# will be too flat to be credible, so a sharper tuning than just tuning is adopted for F natural.
Drones and the second octave: passing into the second octave involves a change of pressure. If the drones are changing pitch with pressure, then assessing the tuning of notes in the second octave will be impossible by reference to the drones. Its easy to be fooled by this.
The absolute pitch of the chanter and the tuning of the scale are separate issues but interdependent.
For example, it is possible for the chanter to play a scale in which each note is in the correct relationship with all the others, but the overall pitch is either high or low. Conversely it is possible for, say, most of the scale to be at the right pitch, with one or two notes a little high or low. In my experience the note D is the best pitch reference. If that note is correctly tuned, and the reed is good, then the rest of the scale should be good. On the other hand if, say, B is low, this usually indicates that scraping has been taken a little too far, and you may be able to correct matters by clipping a small amount from the tip. If C# and G# are unobtainable, then you need to scrape a little more.