Quoting David Ilvedson <ilvey at sbcglobal.net>: > Maybe Wim could send a photo...? > > David Ilvedson, RPT > Pacifica, CA 94044 > Sorry, I don't "do" digital photos. Too much trouble for this camera neophite Wim > ----- Original message ---------------------------------------- > From: RicB <ricb at pianostemmer.no> > To: caut at ptg.org > Received: 11/14/2006 4:32:31 AM > Subject: [CAUT] tight balancier - defining bobble > > > >Hi again Wim > > >One thing is for sure. If your hammers are not even touching the > check > >on medium to light blows... then the field is narrowed quite a bit. > What > >happens when you just push the keys through aftertouch without > enough > >force to let the hammers actually hit the string ? I dont mean like > an > >aftertouch check. Use as much force as you can without letting the > >hammers make contact with the strings. One test I ran into for > >rep-spring strength a while back went along these lines. The > rep-spring > >should be just tight enough so as to prevent the hammers from > checking > >with this kind of test... but no stronger. You should see the > hammers > >dipping say about 8-10 mm before springing back up to drop position. > > >They should dip more then drop but less then check. > > >If you arent getting any of this kind of action then the rep-spring > is > >too tight for whatever other conditions you have. Tight hammer > centers > >will slow things down for example so a certain combination of these > / > >tight balancier pins and strong rep springs could cause your > trouble. > >Even if each of the individual parameters seem ok when checked > >by-themselves. Point is... if the tails are not even hitting the > >checks.. then it cant be really much of anything else. At least not > > >unless something else is ridiculously out of wack. > > >What else could cause the hammers to hang up so much that hammers > wont > >even touch the checks ?... Hmmm... I suppose a lot of rather strange > > >stuff could get into the picture... but I cant think of anything > >reasonable off hand. Perhaps a very strong jack spring with minimal > > >knuckle clearance could contribute.. ? I dunno.. what kind of > strange > >tail arc and check angle could cause what you describe below ? > > >In any case seems to me you want to make sure whether the tails are > > >actually making contact with the checks or not at this point. Maybe > mark > >a few of the worst offenders with a bit of chalk on their tails and > see > >if it rubs off on the checks ? > > >You really got an interesting thread rolling in any case there Wim. > > >Cheers > >RicB > > > > > Hi Wim > > > > > > Are they actually bouncing off the checks ? Or are they > simply > > > hitting > > > the rep lever and getting sprung back up before they even > touch the > > > check ? > > > > > > Cheers > > > RicB > > > It's hard to tell. I beleive they don't even make contact with > the > > check, but I've had notes that even on a medium hard blow, much > less a > > hard blow, where the hammer doesn't check. It acts like it is > not even > > touching the check, but it goes down far enough where the it > should be > > hitting the check. But if I move the check forward, the tail > hits it > > on the way up. > > > Wim > Willem Blees, RPT Piano Tuner/Technician School of Music University of Alabama Tuscaloosa, AL USA
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