Hi Joe, I believe that the size of the key pins is a result of choosing the size for the mortises. In the case of the .144" (or .146") balance rail pins, if you add .100" for 2 pieces of medium thickness bushing cloth and .004" for play, you get .250" (a convenient size to make the mortises - .250" drill/router bits are easy to find) and a relatively nice fit. I'm not sure about the .133" pins, but there's probably a metric equivalent. Respectfully, Jon >I,m working on a Kawai Grand Action. Just took the measurements for the key >pins!!! My first reaction was.....What the Hell? The front pins measure: >.133" which is 3.37mm! The balance pins measure: .144" which is 3.65mm! To >me that makes no damned sense at all, by metric or machinist measurements. >Anyone have an explanation for these stupid measurements? Of course, none of >my key bushing cauls are the proper size for this! Sheesh! Gawd, I'm having >fun! <G> I'm trying to keep a sense of humor, but this sort of thing is just >stupid, IMHO. >Regards, >Joe Garrett, RPT, (Oregon) >Captain, Tool Police >Squares Are I > >_______________________________________________ >pianotech list info: https://www.moypiano.com/resources/#archives -- Jon Ralinovsky Piano Technician Department of Music Miami University 513/529-6548
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