[CAUT] Bobbling hammers

[Jim Busby]

List,

Another "duh" moment. I've been dealing with this Nordiska upright and tried several things to stop the bobbling hammers. The specs were brought up to par (a bit of geometry work there. See below.) so aftertouch was present and the jack was able to get out of the way. Several things were tried, like weakening the damper springs (For the life of me I still can't see how this could be an issue anyway, because the bobbling occurred even when the sus pedal was engaged.)

Then it dawned on me to check the pinning... Basically, zero friction.

I repinned the hammer line. Problem gone.

This is the FIRST thing I suspect on grands! Excuse me while I pick up this mallet and plant it in my forehead...

Jim Busby

BTW, Bending the dowel capstans (wire) to engage the wippen further back gave me the answer to the geometry issue. Any further and I would have had to move the action bracket posts, or moved capstans/wippen heels, but it worked out "OK". .410 dip, 44mm blow, normal Letoff. Even though I'd like less dip and more blow. (It was .460 dip 42 blow, and ½ inch Letoff)

Thanks to all.

JB
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