Thank you all for the good thoughts. As mentioned, the piano is not in my shop and I don´t know if the player is satisfied with my approach of scamping with the let off because he will be back not until weekend (his father opened the door). Usually I am a friend of the method of explaining the player to learn how to work an action correctly, but in this case me too I felt the resistance. Most promising sounds to me the balance hole reamer thing. It´s a little embarrasing that I have such a tool but I allways thought that it is made for using from the bottom and not from the top. I thought it is made for enlargening the hole and was annoyed at that stupid guy who invented that tool and who was not able to deliver it in the correct size :-) That´s the reason why it is not in my toolcase but tomorrow I will search my shop for that beast. And I can imagine that the hole thing has to do with dryness. But I would assume that the problem should arise with moisture, not with dryness. Gregor From: pianoforte at pianofortesupply.com Date: Thu, 22 Jan 2009 10:10:27 -0800 To: pianotech at ptg.org Subject: Re: [pianotech] Bobbling hammers and jack spring pressure? Gregor, you have had a lot of good advice and things to look for. I would like to add two more things, although I do not think they are humidity related: You say the player senses increased resistance deep near the bottom of the key dip. 1) Front rail punchings: One thing could be that the front rail punchings are thing and spongy. When testing for after touch, a technician will often press the key right down to the bottom so it is resting solidly on the front rail punching. When player is playing moderately, a front rail punching which is not firm enough will give the player resistance up to and over 1 mm before the key is really bottomed out. Result: the hammer bobbles. As a test for this you can remove one front rail punching and set key using only cardboard punchings. Set dip to the specs and see if the hammer still bobbles. If it does, the front rail punchings are not firm enough. 2) Balance pin holes in the bottom of the key: if the thickness of the wood at the bottom of the key at eh balance pin hole exceeds 3 or 4 mm, the player will encounter resistance near the bottom of the keystroke. Test for this by removing the action and the FR punching on one key and slowly depress the key to feel for resistance at 10 mm dip - there should be none. If there is, use a balance hole reamer (JD would correctly say counter-bore) and remove material from the inside of the balance pin hole from the top Jurgen Goering Piano Forte Supply (250) 754-2440 info at pianofortesupply.com http://www.pianofortesupply.com _________________________________________________________________ Invite your mail contacts to join your friends list with Windows Live Spaces. It's easy! http://spaces.live.com/spacesapi.aspx?wx_action=create&wx_url=/friends.aspx&mkt=en-us -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech_ptg.org/attachments/20090122/e1830191/attachment.html>
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