keymaking

The single keys are made in four parts.

  • A turned pad either Ø8mm(5/16") for the upper keys or Ø9.5mm(3/8") for the lower keys.
  • A strip of drawn brass 3/16" x 3/32" for the shank of the key.
  • A spring beaten from Ø3mm (1/8") drawn brass rod.
  • A rivet cut from Ø2mm drawn brass wire.

    • The material could also be Nickel Silver (also known as German Silver) instead of Brass.
    Nickel Silver keeps its polish longer and is often used if a set is not to be plated.

    Drawing of the key padsThe pad end of the key is turned from Ø9.5mm(3/8") rod for the larger keys (mainly those that point downwards) and Ø8mm (5/16") rod for the smaller keys (mainly those that point upwards).

    Forming the key shank

    The main part of the key is beaten and filed from 3/16" x 3/32" section drawn strip.
    beating the key topSoften about 12mm (1/2")" at the end of the strip by heating red hot and allow to cool.
    Using a smooth faced anvil hold the strip on edge and start to flatten the end. The work will need to be resoftened at least once during the process. beating the key side I start the flattening using the main part of the hammer and, after resoftening, I continue working the end using the ball end of the hammer until it is wide enough for the final shape of the touch piece to be filed.
    Be prepared to cut off the end and start again if things go wrong. It takes some practice to achieve a good forged end. Do keep the work annealed as, if the piece is worked too much between annealings the material will crack. This is especially true in the case of Nickel Silver.

    Shaping the key shank

    File the touch piece of the key to your chosen shape. Take care to get the shape as precise as possible as clumsy keys are ugly to look at as well as hard to play. Avoid making the chanter look too heavy.

    After shaping the touch piece of the key offer the key up to the chanter over it's slot and mark the position of the center of the pad seat.

    beating the key topCut the key blank to length plus at least 1.5mm (1/16"). File the thickness of the key down from 3/32" to 2mm. This dimension must be a good fit in the lined slot in the chanter. The filing of the key to the correct thickness is a time consuming chore and is only necessary because I have not found a source of 2mm wide drawn brass rod. This may now be available but I am still using existing stock.

    Fitting the pad

    File the key to approximately the correct side profile and finish off the shaping of the touch end.

    beating the key topPlace the turned key end, with a dummy pad under it, over the hole in the chanter, and fit the key to it by filing the end until no obvious gap is visible. beating the key topFile end to a point in plan view as shown.
    Remove both parts from the chanter and set them up on a fire brick and silver solder the joint using Easy-flo solder, not soft solder, together with Easy-flo flux. To ensure a good joint, both parts must be clean and care must be taken to apply only enough silver solder to fill the joint. (This can be simplified by flattening the end of the silver solder rod or by obtaining silver solder wire of about 1/2mm diameter). After cooling, clean off any excess flux and file away any solder fillet to give a neat, square, joint.
    Re-fit the key to the chanter and mark lightly the pivot position, using a 1mm drill held in a pin vice. Drill the pivot hole 1.1mm diameter and refit the key to the chanter checking that the pad end of the key does not foul the sides of its counter bore.

    Springing the key

    conplete key sideDrill the hole for spring rivet, 1mm diameter, as close as possible to the touch end of the key (but not in the beaten part unless the key is one of the short keys), and counter sink lightly from the underside of the key.
    The spring is made from 2mm diameter drawn brass rod, hammered flat without annealing, until it is between 0.5mm. and 0.75mm thick, and very hard and springy. From this the springs are cut just under 2mm wide and of length suitable for the key. A hole 1mm diameter is drilled in the centre of the width, about 3mm from one end, and lightly countersunk both sides. The spring should now be shaped as shown in the drawings.
    riviting thr springThe rivet is cut from 1mm diameter brass wire and silver soldered into the hole drilled for it in the key taking care that the fillet of silver solder only just fills the countersink (if too large a fillet is made the spring won't seat properly). Place the spring onto the rivet and check that it will still fit the chanter.
    Clip rivet to length (about 1mm. protruding above the spring.), and, using the ball end of a Ballpein hammer, spread end of rivet to a mushroom shape. Don't flatten the rivet too much or it will be weak. File the rivet flush with the outside of the key. Smooth and polish the key.
    Finally, fit the key to the chanter and check the action of the spring. As a guide, the end of the spring should touch about 2mm. behind the pivot on the long keys and 1mm on the short keys to give a light smooth action. If the spring is too far from the pivot the key will be heavy to open, and if too close the key will not seal reliably.

    DOUBLE KEY MAKING.

    beating the key topThere are two differences in the making of double keys. Firstly the shaft of the key is offset, and secondly the longer key must have a recess along its length to clear the pad of the shorter key.

    double key 1On the longest key a piece of 3/16" x 1/8" nickel silver strip about 15mm. long is silver soldered in the approximate position of the shorter key pad.

    double key 2When each key has been individualy fitted to its slot, and its pivot hole marked and drilled, the two keys are put together on a single pin and the cutout marked as shown to allow a small clearance on the pad of the shorter key .
    The recess is then filed to the scribed line and the outside shaped as shown, to give the key an even cross section 2mm. wide.

    NOTE:
    The 3/16"x3/32" 15mm. long strip can be silver soldered at the same time as the shaft to key pad joint is done to avoid the chance of softening one joint whilst doing the other.

    The remaining work on the key, springing and polishing , is exactly the same as the procedure described for the single keys.

    Adjusting and padding

    In order to get the best possible performance from a chanter, the key pads must be airtight when lightly oiled. Leaks can be caused by a number of faults.
    1) Key head at wrong angle.
    The head of the key to which the pad is glued must be square with the pad seat cut in the chanter. If this is not the case, the head must be adjusted using a small pair of pliers. Protect the jaws of the pliers with masking tape, to avoid marking the key, then fit a new pad.
    2) Key seat badly cut or damaged.
    This is difficult to remedy and care should be taken to get the seat right when it is first cut.
    3) Key badly fitted to the slot. (too loose)
    This can cause the pad to sit in random positions and, whilst this makes little difference on a conical seat, it can cause severe leaks with the more common flat cut seat. A partial cure can be effected by using shims cut from thin brass or plastic, fitted into the key slot beside the key, and held in place by the pivot pin.
    NOTE:
    A small amount of side-play is needed to ensure that the key does not bind, but this should not exceed 0.5mm, measured at the tip of the key. for a short key or 1mm for a long key. Any more than this is too much.

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