Terry, Your idea about the variable thickness of the Hammer Shank Rest Rail is not a good one. I suspect there is something else wrong. First thing that comes to mind is the hammer butts are resting on the Jack Tops, i.e. lost motion is incorrect. Second thing: the Hammer Shank Rest Rail Supports are miss adjusted. (these are bolt that support the rail. they go down between the keys and have a nut on the top and one on the bottom of the keyframe, in the back. They are accessed from under the key frame. Also, what kind of Hammer Rest Rail Felt did you use? If you used Upright Hammer Rail felt, it is way too thick and spongy! The correct felt to use is Medium-Thick Action Cloth, glue on one side of the rail only. Regarding the dip, it should be 3/8", unless it is some European POC. Or, if it is pre-1850, it could be 1/4", as in some Chickerings. (refer to Faust's little book). BTW, quit with the Metric crap! I don't do Metric! Also, Make sure the rails are all SEATED snuggly on the action frames, (brackets). Lastly, when you have the action out of the piano, is your work bench absolutely FLAT? Or is it wowed? Make sure the key bed, in the piano is absolutely FLAT. If it is not, then you have to duplicate the key bed curvature on your bench! The key frame is VERY flexible and that one thing can really screw up a lot of things. BTW, there needs to be some lost motion between the butt and the jack. I would say about .005". That is also, a MUST! Also, make sure the backchecks aren't holding the hammers up, i.e. did you recover the backchecks and not re-regulate them on the bench?<G> Hope that helps some. Joe ----- Original Message ----- From: Terry Farrell To: joegarrett at earthlink.net Sent: 1/28/2013 3:48:22 PM Subject: Fwd: [pianotech] Square Grand Questions for Joe Garrett Begin forwarded message: From: Terry Farrell <mfarrel2 at tampabay.rr.com> Date: January 27, 2013 10:01:10 AM EST To: pianotech at ptg.org Subject: [pianotech] Square Grand Questions for Joe Garrett Reply-To: pianotech at ptg.org Helllloooooooo Joe! I thought I'd post this to the list in case anyone was interested. I have the action back together, but find that the key dip for most of the keyboard is just over 1/4-inch (about 6.5 mm) - quite shallow. Is this the norm for these pianos? In the very low bass, the key dip increases to a bit more than 3/8" (about 10 mm) - reflecting the key ratio changes you described I presume. I have to do something about the hammer blow distance in the high treble because the hammers hit the soundboard ribs when you try to install the action in the action cavity. The only way I can see to do that would be to use thinner hammer rest rail cloth or increase lost motion (without jacks in place, hammers moved enough to clear ribs). If 1/4" key dip is too shallow (I should thing that to be the case), seems to me that I should try some thinner hammer rest rail cloth - maybe even something that tapers in thickness - such that I have thinnest in high treble, less thin in treble, only somewhat thin in tenor and full thinckness that I have not in bass - basically, use the hammer rest rail taper thickness to get key dip to 3/8" (9.5 - 10 mm) over the entire keyboard - that should solve my hammer clearance problem also. What do you think of this and what is the norm for key dip on these pianos? And before you chastise me for not necessarily using an exact replacement for the hammer rail cloth, the cloth on the piano before I rebuilt it was pretty chewed up and worn out and I don't know that it was original anyway. ;-) Thanks for your input. Terry Farrell -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://www.moypiano.com/ptg/pianotech.php/attachments/20130128/e9d8f600/attachment.htm>
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