In 2009 we were asked to rebuild the 1903 8ft Ibach grand that had formerly been in the drawing room of the Sisters of Mercy convent, where Dame Sister Mary Leo taught. The brief was for us to rebuild this heritage instrument to performance standard so it could be used at Auckland's St Patrick's Cathedral.
This was a major rebuild which included a new soundboard, tuning plank and bridges. Major technical problems had to be overcome, not least of which was the original poor design of the capo bar - a part of the frame.
The treble of this piano can never have been great as the capo bar was made of wood, with steel wire embedded in it - all sitting on a layer of lead. As you can see from the photos, over the years the force of the treble strings had crushed the wood, resulting in the strings being muted by the timber. Astonishingly, the piano had been restrung and left like this.
To solve the problem we designed new capo bars, good string approach clearances and a functional capo radius, as well as correcting the hammer strike line. We had CAD drawings made of the replacement bars and used a 3D printer to create 1.5-percent oversize "masters". Then we used the masters to cast the new capo bars in phosphor bronze. The underside of the frame needed to be machined to accommodate the new bars.
Completing the rebuild: We adjusted the tenor string scaling by adding new wound strings and added specially-manufactured hammer shanks. We also used NWG adjustable frame fixtures to fasten the frame and refreshed the cabinet polish.
An unusual feature of this instrument's design is that the una corda (shift) pedal moves the keyboard to the bass side, not the treble side. Interestingly, a pianist who had been playing the piano for a while hadn't noticed until I pointed it out. So although technically very unusual, it doesn't seem to worry players.
It is particularly pleasing to hear this instrument now being used at the cathedral again.
See photos of the rebuild below