First, all damper felts need to be trimmed and/or cleaned. I clean the felts using compressed air – it’s a delicate operation, but well worth the careful effort.
Trimming damper felts requires a perfect pair of scissors. Previous posts have shown how to trim the split wedges (Lift Noise Trimming), but below is a pic of the bass single rider dampers, the sides of which become splayed with use (and thus rub on neighbouring dampers, sometimes blocking movement).
(the odd bits of felt lying amongs the riders are the side trimmings):
trimmed bass riders
Then the damper lift can be regulated. This is done with simple bending in or out of each damper wire. Of course, you have to know where to bend the wires – but with practise it makes for a very satisfying job.
Regulating damper lift
Then the damper springs can be regulated. This is often forgotten, but it’s so important to ensure that individual damper springs are similar in strength to their neighbours, otherwise this effects the key touch weight.
Regulating damper springs
Finally, the half-blow can be regulated, by adjusting the spoons on the back of the levers. This also is vital for even touch weight. (no pic)
Sometimes dampers wobble as the key is pressed, especially on a hard blow, and can actually produce an audible vibration (a strange and annoying sound). Dampers with extended wires (usually at tenor/bass breaks) are particularly prone to this.
There are 2 remedies:
1 Replacing the wire guide felt.
2 Cutting back the damper head and re-cranking the damper wire (so that the damper head protrudes less, and so vibrates less).
Usually, both remedies are required – though as you can see from the pictures, only a 1.5mm thick sliver had to be removed, and the head sits just that amount closer to the plate arm…and now doesn’t vibrate!
Showing cut sliver (protruding)
The newly cranked wire
First bass damper now closer
Many quality keyframes have Dome Screws to adjust how the frame rests on the keybed. Most dome screws are adjusted using a tuning hammer or special key.
Many Piano People do this on the work bench, using a straight-edge; some draw slips of paper between the dome screw surface and the keybed. Neither of these methods are reliable – or easy.
This is the best method:
With the keyframe (and full action) in place on the keybed and cheek blocks screwed in position, tap obliquely down onto the key chasings close to each dome screw, lifting the keyframe as you tap (by pulling on the dome screw head or pressing up on the stack – as in the picture of a Bluthner concert grand) until you hear knocking (of the dome screw on the keybed).
Tapping the Chasings
The aim is to adjust each dome screw so that minimum lifting is required to produce knocking, thus putting as little tension into the keyframe as possible. Adjusting each dome screw may affect its neighbouring screw, so check up and down the keyframe several times.
For initial crude adjustment, try pressing down on the head of each dome screw. If this produces no visible movement of the hammers, the dome screw must be in firm contact with the keybed – and thus is either correctly adjusted or screwed down too far. Confirm this by tapping the chasing + gently lifting the stack. (if it’s screwed down much too far, it will be difficult/impossible to lift the keyframe clear, so you’ll get no knocking.)
Gap check: lifting the stack
Whereas, if pressing down reveals downward movement of the row of heads, there’s obviously a gap between dome screw and keybed: the screw must be turned down. Keep turning it down until the stack lift+chasing tap produce knocking. Now check neighbouring dome screws. Etc….
Sounds labourious? Once mastered, this method is quick and failsafe.
Size isn’t everything in the piano world….Because, though these hammers had a very good felt length and the correct width, they were far too HEAVY.
This early model O Steinway also lives in a Romney Marsh church, so stiff keys and sluggish everything else needed as much help as I could offer.
With keys already loaded to the hilt with lead, the only way forward was to lose as much of the hammer wood as possible. Time to get out the old sander…..
Hammer Tail Shaping/Reducing
It wasn’t perfect – but after reducing the hammer wood, I managed to weigh out the keys to 48g. This is certainly better than the 65g + they were clunking at before!!
Harpsichord voicing, like FortePiano (Early Piano) voicing, is much more closely linked to the instrument’s regulation.
The process and principles of voicing, though, are the same for any instrument: giving form and equally graded variability to each and every note, throughout the range.
Voicing this 1984 Double Manual Harpsichord by John Horniblow was a delight, thanks to his excellent construction. There are 4 stops (2x 8′, 1x 4′, 1x 2′), so many Jacks and Plectra to work through….
A Superb Instrument
Rich Jack Row
Sometimes, where hammers are angled on the shanks and there is little room, cutting bevels across the felts is the only way hammers will travel freely.
The Knife That Did
Having the right knife to do the cutting is essential – I made this one back in the 80s:
Once hammers are nicely profiled* they can be ironed. Ironing is not merely cosmetic: it ties in the exposed fibres, protecting the felts from dirt & dust.
*Ironing can also be used as a temporary (and very mild) way of firming up the hammers and the tone – especially when a piano is in a humid environment. In this case, the iron is drawn over the hammer sides.
front & back
pressing on a hot iron