<html> <head> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii"> <meta name=Generator content="Microsoft Word 10 (filtered)"> <style>  </style> </head> <body lang=EN-US link=blue vlink=purple> <div class=Section1> I have been taking care of a C7 Yamaha in an old Presbyterian Church with curved floor.  It has a complete climate control system properly functioning.  I have had much trouble with climate stability in this room but now that the two churches sharing the piano have made sure the piano’s floor length cover gets replaced in between uses the changes seem less dramatic.   However there seemed to be damper problems in the spring summer months.  The damper tray goes from lifting all at once to being to fast in the middle.  Today I went to tighten tray screws and found them all so-so.  So I tightened them all and the sustenuto rail screws. In doing so with the tray screws I tried to force the tray level.  The dampers at both ends still lift too soon.  But also a few dampers in the middle seem not to seat properly.    Remember this piano is on a curved floor and from Bass end to Treble end I figure it tilts 1-9/16”.  I used silk thread tied to gram weights as a plum bob measured down the rim was (5-16th for 12-3/4”) Piano leans to the Bass end.   Two things visually can be seen the trichord felt is sliced a bit off centre, the other is that the flat felt has drifted to the bass end and is almost missing the right string.  Testing the strings by plucking the bass side was bleeding through.  I’m figuring I am seeing excessive depression and poor centering of the dampers in the tenor C#-4 and D#-4 both trichord felts on the back of damper head wouldn’t fall down completely between the strings only on soft blows but dampen okay on a harder blow they seem to work okay with the pedal (no hanging up).   I replaced the trichord felt only on D#-4 (the most offensive one) and rebent the wire to pull the flat felt back to centre position (bent at the top two bends closest to the head) so that the flat felt would cover the right string.  I made sure that the wire was free enough through the guide rail and I leveled the strings.  It dampens better now.   On the C#-4 I just made sure the wire was free and the timing was okay.  I didn’t even notice when I started today that this one was a problem.  I didn’t get this one working as well as it should be.   What I will have to do is replace all the trichord felt and centered and space the wires for the notes with combined trichord and flat felt.   The remaining 3 notes in the top of the tenor are flat felt on both front and back of the heads.  These are not working properly either.  The right strings are almost cleared.   The damper wires are nickel plated and they show a black line (can be easily wiped off) where they contact the guide bushing.  The bushing cloth is very heavy.   There are two things that seem wrong here.  There are very noticeable compression ridges in the sounding board and I wonder if the belly rail is affected too causing the damper guide rail to rise and the dampers to go uneven in the middle and also for them not to rise and fall less far because the strings might move up too.  (if this were true wouldn’t the dampers track to the right string but maybe because the guide rail moves to the right the angle change forces the damper to the left.  I know that these things are all corrected by winter and I can’t be by the piano’s side to make sure it keeps getting covered up.  (The easiest thing to do in all these cases is to ream the guide rail hole more.  But I hate too much movement in the dampers all that extra noise and it won’t fix the pacing problem.   I am wondering has anyone else had gravitational/friction problems with grands on curved floors?  Could this effect the wear on keys and dampers and action centre pins?  Doesn’t it make sense to level out a piano than run these risks?    To be honest they had built a leveling stage that rolled around (Chrysler engineer is a parishioner).  Then, they removed the piano from the stage.  I think the piano functioned better on the stage.  I am recommending that they level out the piano before I go through all the work on the dampers.   Jessica Masse RPT Piano Technicians Guild   </div> </body> </html>