If you measure the up and down weight on the notes you are sampling you will be able to calculate the friction and know instantly whether you have a friction problem or not. David Love davidlovepianos@comcast.net -----Original Message----- From: caut-bounces@ptg.org [mailto:caut-bounces@ptg.org] On Behalf Of Fred Sturm Sent: Monday, August 01, 2005 9:49 AM To: College and University Technicians Subject: Re: [CAUT] Touchweight, etc. On 7/31/05 2:05 PM, "James Ellis" <claviers@nxs.net> wrote: > I deal with the friction first. Keys first, absolutely, before anything > else, then the various action centers. There is no sense fretting with > action centers if the keys are binding. To do a thorough job checking the > keys, the stack must of off. You will find things you can't find if the > stack is on. After you have the keys all in good shape, deal with the > action centers. Don't overlook mundane things like rep levers rubbing on > adjacent knuckles, and stuff like that. I agree with Jim Ellis 100% on this. Don't even look at weight until you have examined friction, particularly key friction (and then alignment issues). For key friction, yes, the stack must be off. To check the keys thoroughly, use lead counterweights on the backs of the keys. A couple jiffy leads, and a couple half jiffy leads, will serve very well. Place them on each key in turn, enough weight and placed so that you counterbalance the key leads, so that the key is balanced and doesn't want to go one direction more than the other. Then nudge the key in either direction (down in front, down in back). It should move freely - float. There will be a difference in response from bass to treble, due to change in mass, but it will be obvious which keys have friction issues, and you will see much more than can be found by other means. Even tiny amounts of balance bushing or balance hole friction will show up in an obvious way. This goes pretty fast, as the number and placement of weights will (or should) change very gradually as you go up the keyboard (a bit of difference from sharps to naturals). You will also see where keys have been weighted unevenly. If that is the case (and it nearly always is, at least to some extent) mark the keys that are unevenly leaded, and consider just removing an obvious lead or two where that seems appropriate, before your later, finer leading work. (If it's really haywire, do a pattern leading, but that's another topic). Unfortunately, the key weighting folks in most factories are not well trained, and lack curiosity - they solve all problems by adding lead. This seems to be true in most factories to a greater or lesser extent, and many rebuilding shops are also guilty. Once you have addressed key friction, and looked closely at alignment/rubbing issues - visually making sure there is no contact of hammer felt, knuckles, reps to neighbor knuckles, etc. - a quick check of other friction is simply to do a quick upweight check. Use a 15 or 20 gm weight, quickly along the keyboard, marking any that don't raise the weight readily. Then examine those notes and find out why. Doing this quick and efficient work ahead of time will save lots of time fussing and puzzling later. It's like doing the pitch raise ahead of fine tuning. Regards, Fred Sturm University of New Mexico _______________________________________________ caut list info: https://www.moypiano.com/resources/#archives
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