This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment ----- Original Message -----=20 From: Delwin D Fandrich=20 To: pianotech@ptg.org=20 Is that really what it says? The bubble gages I used at the factory = were supposed to be calibrated to indicate a deflection of 17 minutes of = arc which was supposed to translate to 0.5% string downforce. I.e., with = a string having, say, 175 lbs of tension a bubble gage deflection of one = gradation indicated a string downforce of 8.75 lbs. I have to admit I = took the above at face value and didn't do any checking to verify, but = that, at least, was the theory. Del Thank you for that post, Del. Finally the plot thins. The sheets I borrowed include figures 1 thru 6. Although no mention = in the text refers to angle but mentions divisions, the pictures of a = bridge and the gauge clearly show and say that 1 division equals 1/2 = degrees bearing. I don't know how to type the symbol for degrees so = I've spelled it out.=20 There is also an 8 page discussion of downbearing by Alan Vincent and = it does show the relationship as you noted. Yes, one division is 17' of = arc and he lists one division as .5% on the last page. The first page of the instructions entitled "Procedure to establish = proper down bearing of strings on bridges of Baldwin Grand Pianos = designed with hollow vertical (Acu-just) hitch pins." gives the = procedure and contains the conclusion that I mentioned about not being = able to recheck and that statement I attributed to advertising. = Attached to this sheet were the drawings of the gauge and bridges with = the labels that are obviously in error. Thanks for clearing this all up. Regards Carl Meyer Assoc. PTG Santa Clara, California cmpiano@attbi.com=20 ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/16/96/0b/12/attachment.htm ---------------------- multipart/alternative attachment--
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