[pianotech] Petrof grands

[Dale Erwin]

Hey Paul
  I like these pianos tonally but the action guys ...what were they thinking?  Here is the short version.  
  Nice action ratio. Its 5 or 5.3 to 1. Then they shot themselves in the foot by installing hammers that weigh over 1o grams in the bass and on into the trebles. SO they over powered the action ratio with hammer weight. Then added lots of lead and maybe a wippen assist spring and viola ....an action that's heavy aaaaand there's no up-weight either.
 Solution :....remove hammer weight or install new lighter  hammers. Then with the hammers lifted out of the way.... weaken wippen springs till the weight of the wippen is barely supported, Or just starting to show that it wants to rise.....then re-weight keys with springs engaged.
 Now it works

 

 

Dale S. Erwin
www.Erwinspiano.com
209-577-8397
209-985-0990
Ronsen hammers/prep
Sitka Sound boards
Belly packages



 

 

-----Original Message-----
From: Paul T Williams <pwilliams4 at unlnotes.unl.edu>
To: pianotech at ptg.org
Sent: Wed, Jun 29, 2011 9:30 am
Subject: [pianotech] Petrof grands


Hi All,

What do you folks think about PetrofGrands?  We were just donated a 1985 6'5" Walnut Polish grand. It's been maintained extremely well, but is about the heaviest playingpiano I've ever come across.  I've never worked on a Petrof grand,only a couple of uprights in my 20 years in this crazy business. It wasdelivered to my shop this morning and will probably live in our University's"welcome center" lobby, so only played a few times per year. It's really heavy and built like a tank like old Mason and Hamlins. 

I'm considering trying the TouchRailsystem from PitchLock Co.  Has anyone tried it out?

Thanks
Paul

 
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