1/2" angle iron 4' long Joe Goss RPT Mother Goose Tools imatunr@srvinet.com www.mothergoosetools.com ----- Original Message ----- From: "David Renaud" <drjazzca@yahoo.ca> To: <pianotech@ptg.org> Sent: Friday, February 24, 2006 3:42 PM Subject: keybed spring > Korlore & Campbell, for a music school, one year > old, tuned twice so far. > > Call for sticky key. > > Key is rubbing on the key slip. > > Upon removal of the keyslip, I notice how tight the > key slip screws are, and all the powder sawdust coming > out with the screw. > > Upon inspection the key slip appears straight. > > Placing the keyslip back, it touches the keybed > at the ends, but there is a bow towards the middle > with over a 1/16 inch gap at center. I push upward > on the bottom of the keybed with my thumb only and > watch while the keybed wood itself flexes up and down > in the center and also observe the keys rising and > falling. The keybed is a spring > > I notice that with the key slip removed the entire > middle of the piano has severly bubbling hammers. > Putting the keyslip back stops the bubbling, but > the keyslip rubs the front of the keys. > > I determine that the keybed is warping. The downward > pressure is forces the keyslip to torque > towards the keys. Tight key slip screws were due to > torque of bending the keybed upwards. The dust > coming out with the screws was the light material > developing stripped screw holes under the torque. > > Being a squeezed emergency appointment for a sticky > key , I comprimise by leaving one screw out so as not > to torque the keyslip and keybed together so much, > adjusted extra let off to eliminate bobbling hammers, > and said I would e-mail a report. > > I can not see a solution to this other then perhaps > putting a strip of plate steel under the keybed to > freeze it straight. With nothing but dust to screw it > into, bolts through would be required. > > I can bend the keybed about with my thumb alone. > How can one be expected to regulate that, the keybed > itself is a mushy energy absorbtion spring. > > The first time I tuned this piano I was impressed to > find a clean sounding chinese piano that was tunable. > I am not so pleased afterall. This is bad for > business, it smells of mechnical instability, > callbacks, and unresolvable issues. I piano I actually > can not work on mechanically > > 1) Steel plate?? thoughts....... > 2) How many have seen this.....other solutions > > I will try to fix anything, but this looks like > soft, spongy warping material that can not be worked > with. I feel it is a total waste of time to regulate > it, come spring everything will have changed > dramaticly. grrrrr > > Somebody is going to think up a fancy technical > name.....accelerated keybed spring action.....and > someone else is going to think it is a good idea and > patent it.......sorry..... > > Feeling dramatic > Dave Renaud > > > > > > > > > > > > > > > > > > > > > > > > > > > __________________________________________________________ > Find your next car at http://autos.yahoo.ca > _______________________________________________ > Pianotech list info: https://www.moypiano.com/resources/#archives
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