Plate to pin contact, (was marking)

A440A@aol.com A440A@aol.com
Sun, 17 Oct 2004 08:19:22 EDT


David  writes:

<< Lastly, I wonder, how do you (no one in particular) reconcile plate/tuning 
pin contact with the various efforts outlined in the recent thread "Drill 
bit size for #1 gauge tuning pins"  >>

Greetings, 
    I have a real problem with accepting that the "original" design was for 
the pins to contact the plate.  First, there is no way that dimension could be 
kept consistant in a production line.  They have enough trouble getting the 
pins anywhere near the center of the hole, so I don't think they could align 
them closely enough to work. In 1980, we got a D that had the last three holes 
drilled so that the pin was binding against the plate, within a year, they had 
become too loose to hold torque.  When I removed them,(under warranty), and 
ground a little off the plate, a 2/0 pin simply dropped into the hole! I surmised 
that the pin itself had "filed" the block as it was driven in against the 
plate, and when the metal to metal pressure finally ground itself away, there was 
nothing left. (I plugged it with 3/8" Falconwood plugs and redrilled. A 
repair that lasted 20 years.) 
   Also, the problem of "flagpoling" depends on not only the torque in the 
block, but the technique of the tuner. I don't have more difficulty with the 
unbushed plates, in fact, the last few cents of a strings pitch I set with pin 
flex. From any given position of the tuning pin, a stable pitch can be had over 
a range of several cents, unless there is insufficient friction over the 
bearing points.  
Regards,  



Ed Foote RPT 
http://www.uk-piano.org/edfoote/index.html
www.uk-piano.org/edfoote/well_tempered_piano.html
 

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