bechstein

[David Ilvedson]

New parts will help the friction problems.   I'm still foggy on this whole thing...you say the 5.7 ration is doable but I could go up a notch...that means 5.8 or 5.6?   I'm looking at a 1/4 or 1/2 medium hammer weight curve, right?   Do I follow the hammer curve before I hang the hammers...HW...seems easier without the shank in the way?   I have been reading through the archives and I feel like Terry Farrell back in 2002 when he was trying to learn this stuff...   

David Ilvedson, RPT
Pacifica, CA  94044


----- Original message ----------------------------------------
From: "Ric Brekne" <ricbrek at broadpark.no>
To: pianotech at ptg.org
Received: 8/7/2006 2:33:51 AM
Subject: bechstein


>Hi David

>Thanks for the FW's.  You got fairly high friction levels in the two 
>bass notes, and of course that number 16  just plain wild. I suppose you 
>checked and double checked your measurements. Then all of a sudden in 
>the treble you have much lower friction levels and very high BW's.  Your 
>BW is too high all around but especially in that low frictioned treble. 
>All that can be dealt with in the course of installing new parts and 
>regulating the thing once you've decided what you want to do about SW's 
>/ FW's and your ratio.

>With your 5.7 ratio, I'd say your ok with the basic strikeweight curve 
>you have, but you could handle a notch or two up if you want.  Looks to 
>me that you have problems typical of a piano with old parts, and some 
>basic touchweight evening out to do. New hammers and shanks, rebushed 
>keys with balance rail holes dressed up or renewed will help a good deal 
>with the first bit. Appropriate FW's for your SW's, ratio, and desired 
>BW will take care of the basics of your touchweight.  The rest is 
>picking through and troubleshooting.

>I generally approach these jobs pretty conservatively.  I rarely get 
>into changing the ratio. Just pick an appropriate SW curve and more or 
>less do the weighoff from a mathmatical perspective rather then the old 
><<lets get a 50 gram downweight>> bit.

>Cheers
>RicB


>Bechstein E, #158555, 1966, Renner action...hammers not original but 
>appear to be Renner   17 mm KC

>N      U     D     BW     SW     KR     WW     KC        R   FW
>16    24     56     40     10.7     .53     19.5     17mm    6.8   42,7
>17    20     56     38     10.7     .52     20.4     17mm    5.6   33,1
>40    42     55     48.5    9.4     .52     20.4     17mm    5.7   16,3
>41    36     54     40       9.7     .51     19.9     17mm    5.8   19,1
>64    36     54     45       7.2     .51     19.9     17mm    5.8   7,2
>65    37     53     45       7.1     .51     19.8     17mm    6.1   8,2

>Bob M. at Pianotek thinks I need heavier hammers on this 9ft piano.   
>The piano is generally in a studio and rolled out to a stage/gym a few 
>times a year.   I don't think I need a heavier hammer...
>I mocked an Abel Standard hammer on key #33 with a stock weight of 9.1 
>grams gave me, with a 3/8" lead=11.5 grams on the key, a downweight of 
>about 50 and a 25 gram upweight.  The hammer was stock so it needs all 
>the typical trimming which will lower it's weight and lower the 
>downweight and upweight...a lower up weight is not good...

>I