Renner wippens feature precision machined regulating screws and graduated spring tension for optimum regulation. On fine quality pianos this amazing action mechanism, perfected over a period of 300 years, is made from all natural living materials like fine woods, felt, and leather which depend on small action centers to precisely control their motion. These specific tolerances must also move naturally with the environment. Renner action centers are made with exclusive Renner-designed pre-glued and graphited bushing cloth and are designed to be activated millions of times over the lifetime of a piano.

FINE ADJUSTMENT SCREW

Designed for superior fine adjustments after initial rough regulations. Also prevents butterfly spring from wearing a noisy groove in the repetition lever.

The HIGH DEFINITION FLANGE provides a more accurate flange seating on the many different rails produced over the years for both vintage & modern pianos, creating stability in the action and a more accurate transmission of power from key to string.

Renner wippens have three butterfly spring diameters in each set to accommodate the decrease in hammer weight from bass to treble. In order to preserve the proper progression of spring sizes, the wippens must be kept in order when removed from the box. Only the first and last wippen from each section are numbered. The bass section includes notes 1-40; the middle section notes 41-70; the top section notes 71-88. One extra bass and treble wippen (numbered 89) are also included.

One of the little known secrets of every Renner action part is the use of a special wood called Weissbuche - Hornbeam in English - which is naturally air-dried and aged over several years.

The use of only the finest quality materials, including the famous Renner bushing cloth, are among the many reasons why genuine Renner parts are preferred by the world’s finest quality piano makers and rebuilders.