Documentation grand piano by Gregor Deiss, 1815
Exact surveying forms a reference for reconstruktion of the instrument and therefore requires utmost exactitude and precision. A first step is visual inspection for planning the proceedings of survey. For the Deiß grand a combination of procedures is used:
- tactile measuring using a Faro 7 links 3D scan arm:
- with straight tip for locating tuning, bar and end pins
- with angled tip for components not accessible otherwise
- with ball tip for measuring the case
- x-ray tomography for 3D survey of resonance elements
(soundboard, ribs, struts, joints)
- boriscopic survey (position and basic measuring of struts, traces of tools and work processes, materials)
- laserscan of the karyatids
- self made measuring rod for a preliminary survey of the internal resonance chamber
Faro scan Arm
Measuring arrangement for tactile surveying of upper surfaces, achieving a tolerance of 0,08 mm. Of particular importance is the exact measuring of bridge pin positions to establish the scale lengths in relation to the soundboard.
The result is a 1:1 plan in Rhinozerus CAD. This plan is fundament for replication, can be scaled for corrections and can be printed.
base board, levers removed
measuring baseboard, levers included
levers prepared for measuring
investigating the resonance chamber using extant apertures
preliminary reconstruction of the inside struts
laserscanning the karyatids, necessary for all four of them since they are different from each other
a scan in Rhino CAD. For other purposes the karyatids could be made using a 3D printer or a CNC milling machine.