Vertical Damper Lever Set Screws

[Piesik, John (JPIESIK)]

On the back of the damper levers, on some new verticals (Petrof), are little
brass set screws. These set screws appear to aid in factory regulation, most
likely, on some sort of bench fixture (my guess), in order to quickly
regulate the pedal-to-damper lift adjustment without having to bend damper
wires.

The problem is, these set screws, separated only by the damper lever felt,
rub on the chrome-plated damper lift rod. The result is a very noisy,
irritating grrrrroan when the sustain pedal is depressed. It's my opinion,
that if left as is, eventually, the felt between these little set screws and
the lift rod will eventually wear out resulting in metal-on-metal.

I lubed the damper lift rod at the damper lever felts with microfine teflon
and lubed the damper lift rod pivot points with Protek. Still noisy. Next, I
backed out all of those little set screws on the damper levers (next time
I'm removing them completely so they can't fall out into anything). Now the
sustain pedal is whisper quiet. 

However, the damper-to-pedal lift now needs re-regulation (it turned out not
too bad, though). I think it was worth the price to finally be rid of the
sustain pedal "grrrrroaning."

Have you seen/experienced these pesky screws before? I suspect that this new
design may not be worth the effort/expense if we end up having to remove it
to make it work correctly.

John Piesik, RPT