1. Hammer Butt Spring Replacement: English and European Actions
The previous newsletter described the process of replacing Hammer Butt Return Springs on
an older American upright piano action, where it’s usual for all the springs to be fitted along
a separate rail. It is more usual on English and European actions to have the Hammer Butt
Return Springs fitted into the Hammer Butts, engaging with a cord loop on the Hammer
Flange. This article illustrates the replacement of broken springs on an 1880s Bechstein
upright piano.
The photo below shows a Hammer Butt with a broken Return Spring. There should be a tail
about an inch long with a hook at the end, but it has broken off.
First, it is necessary to remove the remainder of the broken Spring. The photo below shows
it being gently prised out here with a pair of tweezers, but an awl might be better.
2. It is then necessary to select replacement springs of a suitable size They come in different
lengths from coil to hook.
The long tail of the spring is then carefully fed through the first hole in the Hammer Butt.
3. Here is another photo showing the Spring tail through the first hole from another angle:
The long tail is then fed back through the second hole.
In the photo above, the tail of the Spring has been fed through both of the Flange holes and
pulled firmly through. The excess length protrudes and needs to be nipped off.
4. Finally the extra length of the tail is nipped off and the spring flattened against the side of
the Hammer Butt (where it passes through the two holes).
The felt Notch Pads were badly worn, some right through to the wood, and these were
replaced, seen here as the red felt pad in this photo of the butt with new spring from
another angle.
The method shown in this article, of attaching the Springs by feeding the tail of the Spring
through two tiny holes in the Hammer Butt, was largely replaced by another method using a
special cord, fed through larger holes in the Hammer Butt and running through the centre of
the coil on the Spring. This may be shown in a future article.
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