For weighing the action parts according to the PTD system

David Stanwood developed a system for analyzing the weight, friction and leverage relationships within the grand action. The resulting knowledge and deep insight into the sequence of movements as a tone is produced are the basis for optimal results when restoring an action.
The harmonious adjustment of the hammer weight to the leverage ratios lead to a balanced and even touch and a pleasant sound spectrum.
European piano technicians are increasingly making use of this method. PRDEA seminars deepen one’s knowledge of cause and effect within the grand action. A greater understanding of how things interconnect lead more quickly to a satisfying and perfect result when choosing hammers or action parts, as well as when weighting a keyboard.
It is overwhelming to discover how any instrument can be brought to blossom by correct selection and optimal adaptation of the various materials to each other.