Greetings all, Many pianos have an inclined (warped) string plane through the tenor section, sometimes severely. And iIf the agraffes are drilled at 90 degrees to the plate surface, then they will all be tilted in relationship to the keybed. In this situation, it's very hard to level strings/mate them to the hammers, (push the left string down, pull the right one up, etc.) and I don't think the results will be all that stable. So, you may want to try this: 1.) Measure string height at each end of the section: i.e.: note # 21: 18.9cm / note # 51: 19.25cm 2.) Place a straight-edge across the strings and see if they somewhat conform to the plane of the straightedge. IOW, are the holes in the agraffes parallel to the (inclined) plane of the strings. You can see this fairly easily, and you can also pluck or strum strings to check contact with your straight-edge. 3.) On the bench, prop the section of hammers at strike height, then tilt them to match the string plane of the piano. (in this instance, raise your hammer prop, voicing block whatever by 3.5cm at note #51. The hammers will now be stair-stepped from bass to treble. 4.) With light pressure, gang-file the hammer crowns until they are all parallel to the string plane. Very little felt will be removed, and the angle is slight, but use care as the hammers will want to tilt if you use too much sanding pressure. When a tenor section is severely sloped, this method works very well. It obviously doesn't guarantee a perfect string/hammer-mating right off the bench, but gives you a really practical starting point. More importantly in a high-use situation, it is sustainable. In other words, once the crowns are tilted (corrected?) to the string plane, it's very easy to maintain shape, voicing and string-level throughout the life of the hammer. I had a real crisis of conscience the first time I did this to a section of hammers, but compared to the alternatives (tilting the hammers, aggressively kinked strings) this turns out to be an easier decision to live with. Btw, in agreement with Bob's comments below, and furtherto, always keep in mind what effect your string bend has on both sides of the agraffe. Best regards, Mark Cramer, RPT Brandon University _____ From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Bob Hull Sent: March 31, 2009 10:26 AM To: caut at ptg.org Subject: Re: [CAUT] agraffe leveling Benjamin, Pushing down on the string would be trying to move the string towards an impermanent position and could result in poor termination. Pulling up too hard could damage the termination surface in the brass of the agraffe. Bob Hull _____ From: Joe And Penny Goss <imatunr at srvinet.com> To: caut at ptg.org Sent: Tuesday, March 31, 2009 9:18:21 AM Subject: Re: [CAUT] agraffe leveling Hi Sloane, Usually not very much movement up is available, so one should not be too agressive in lifting the string and leave something to work with. Joe Goss RPT Mother Goose Tools imatunr at srvinet.com www.mothergoosetools.com ----- Original Message ----- From: Sloane, <mailto:sloaneba at ucmail.uc.edu> Benjamin (sloaneba) To: 'David Ilvedson' <mailto:ilvey at sbcglobal.net> ; 'caut at ptg.org' Sent: Tuesday, March 31, 2009 6:28 AM Subject: Re: [CAUT] agraffe leveling "I tried pulling up the left string" Do you push down strings also? From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of David Ilvedson Sent: Thursday, March 26, 2009 12:05 PM To: caut at ptg.org; pianotech at ptg.org Subject: [CAUT] agraffe leveling I was attempting to level the strings on a newer Yam C6 the other day. According to Goss's leveling device, all the tenor agraffes were way off. I tried pulling up the left string to level but couldn't make enough of a difference. A bad batch of agraffe drilling? I guess in this situation you have to fit the hammer to what you've got? David Ilvedson, RPT Pacifica, CA 94044 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/caut_ptg.org/attachments/20090331/1cf29402/attachment-0001.html>
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