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):
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.
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.
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)