First puzzle of the new year

[Richard Brekne]

Because it is a Petrof !

Could be a number of things, but me thinks your discription of the exact
happenstance should be a bit more precise.

I suppose tho that you find upon play, with pedal down, some keys were
sticking that were not otherwise. This often is a borderline key easing
problem and can also signal some problem with the damper regulation. If
you have tight springs, or dampers which engage too soon, or both.. AND
keys that are just a tads hair on the too much friction side, this will
pop up.

Petrofs have always used really soft felts in just about everything
except their hammers. Sometimes flange bushings are just plain mushy for
example. The same thing goes into their key bushings and tho they can
seem eased, you can have a bit too much friction. I soak key bushings
with 3-5 drops of proteck and make sure the pins are clean as well as
easing. 

Another good thing to do on Petrofs, while we are on them... is to
change the whippen cushion to a much harde felt. Both play and
regulation stability/predictability will improve drastically. I am not a
fan of mushball balance rail and front rail felts either... but just so.
In anycase... these (and some other things) are handy to know about if
you want to do some extra nice prep work on a Petrof for some special
situation.

Cheers
RicB

> Phil Ryan wrote:
> 
> I repaired a rather new Petrof uprignt yesterday that had keys
> sticking down.  After easing a number of the key bushings, all the
> keys were working smoothly once again until I pressed the damper pedal
> and all of a sudden I had a bunch of different keys sticking down
> again.  I eased them and problem solved.  My question is: why should
> pressing the damper pedal have any effect on sticking keys?
> 
> Phil Ryan

-- 
Richard Brekne
RPT, N.P.T.F.
UiB, Bergen, Norway
mailto:rbrekne@broadpark.no
http://home.broadpark.no/~rbrekne/ricmain.html