I don't know if people will answer specifically as you haven't provided enough data and these things need to be calculated. The question I would ask, though, is if you want to "beef up the ribs" then you are changing it and if you are going to change it then why not just change it. Have a rib scale calculated based on the scale design (which can be kept original in terms of its overall tension) and address the issues that you want addressed in the redesign. I don't think anyone will be able to give you a "beef up the ribs by x" answer. David Love davidlovepianos@comcast.net -----Original Message----- From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On Behalf Of Ric Brekne Sent: Saturday, January 21, 2006 7:11 AM To: pianotech Subject: Soundboard rib question Hi folks... Despite knowing that the major rebuilders are probably not going to answer this because they dislike my foul rotten guts (for some mysterious reason... :) ) I will put this to the forum anyways, hoping to get some insights. I have this first year production Bluthner straight strung that I am getting ready to pull the soundboard out of. One of the options I am considering is to alter the ribbing system on this. The instrument measures about 195 cm, and has only 6 ribs. These are not very substantial ribs at that... The ribs are wide and short and get taller in the middle and have a _^ shape as opposed to a rounded shape.. 28mm wide, 9mm tall along their sides, 14 mm tall in the center. There is a long extra "rib" that runs roughly parallel to the bridge and crosses over the cross grain ribs as well. It measures 55 mm wide and 15mm tall. I suppose given the dimensions of the existing ribs this was a so called <<natural>> crowned board in its time (ie compression with flat ribs in a flat caul). My question is just how much beefing up of the system is advisable ? I am assuming the amount of downward force on the board was significantly less then present instruments have. I want to try and keep close to the origional sound picture these instruments had but at the same time I want the thing to be structurally strengthened (if necessary) and try and create a bit cleaner treble then fortes I have heard typically have. I could just pack the thing off to Bolduc and get a re-creation.... a nice easy option I suppose... but before I do that I wanted to hear what some of you think. I will be greatfull for any replies. Cheers RicB _______________________________________________ Pianotech list info: https://www.moypiano.com/resources/#archives
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