Maybe Wim could send a photo...? David Ilvedson, RPT Pacifica, CA 94044 ----- 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
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