Dean, Comments below. Greg Newell Greg's Piano Forté www.gregspianoforte.com 216-226-3791 (office) 216-470-8634 (mobile) -----Original Message----- From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of Dean May Sent: Friday, February 01, 2008 11:09 PM To: 'Pianotech List' Subject: RE: Compression ridges was :Do you dry the ribs, along with the board, prior to gluing ? Greg- >>I had not heard Del's assertion from your first sentence before. What I particularly remember from what Del said was the inverse mass/stiffness relationships between the treble and bass sections. Perhaps he could chime in here if he is on the list and clarify. [I, for one, would appreciate that. What I understand is that both mass and stiffness are present and desired in both areas of the board but one is favored over the other or perhaps better stated one is more important than the other in the opposite areas.] >>Regarding your last statement do I understand that you wish to tie the high treble bridge into the case? My idea was not to tie the bridge into the rim, but the rib below. Instead of having the final treble rib running transverse to the bridge and grain, have it run along the bottom of the final segment of the treble bridge, starting at what would have been the next to last rib and proceeding to the rim underneath the bridge. [You are then, in effect, tying the bridge to the rim are you not? If the bridge is connected to the board and the board to the rib directly underneath and the rib to the rim then the bridge is connected to the rim with no real degree of the flexibility that you say (or that Del said , if that's true) is desired in that part of the board. Something isn't making sense to me here.] I would want to try it with that new rib tied into the rim and also try it with the rib not tied into the rim- just for fun. >>If stiffening the high treble is something to be avoided then what exactly does the treble fish provide? It reduces the diaphragm area (think tweeter) and adds mass to the system. [And also reduces the flexibility of the system up there since it's smaller and can't have the same range of movement as was before the reduction. No?] Dean Dean May cell 812.239.3359 PianoRebuilders.com 812.235.5272 Terre Haute IN 47802 -----Original Message----- From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of Greg Newell Sent: Friday, February 01, 2008 9:38 PM To: 'Pianotech List' Subject: RE: Compression ridges was :Do you dry the ribs, along with the board,prior to gluing ? Dean, I had not heard Del's assertion from your first sentence before. That is very interesting. Why wouldn't the greater flexibility in the high treble also absorb the energy being transmitted there? If Flexibility is NOT desired in the bass then it would seem that Thump may have a point about the usefulness of an old panel, yet I still wouldn't trust it in a CC rebuild. Regarding your last statement do I understand that you wish to tie the high treble bridge into the case? How would that help? If stiffening the high treble is something that you wish to avoid it would seem that this would do that quite handily. If stiffening the high treble is something to be avoided then what exactly does the treble fish provide? Greg Newell Greg's Piano Forté www.gregspianoforte.com 216-226-3791 (office) 216-470-8634 (mobile)
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