Friends... I think I have to go with a larger knuckle to get at least the drop screw problem solved... read the following please and let me know what you think. Thanks.. The underside of the pinblock is så low that I am unable to raise the drop screws any higher then they are. The Hammers are 3 or 4 mm above this point as well and are already pushed down quite a bit while inserting or removing the action....this despite being set at 50 mm from the string. Petrof specifies that they should be at 45mm. This would be impossible on this action me thinks It wouldnt go into the action cavity to begin with, and this would also (with the existing hammer bore) cause an extremely shallow key dip, or tons of aftertouch. Someone has put new hammers and hammer shanks on this instrument some years ago. They are Able hammers and perhaps Renner shanks. The following measurements may be of some help Hammer shank knuckles (rollers) diameter of 10 mm (bolstered with yarn a year ago and still pretty round) Treble hammer bore length is 57 mm total length is 75 mm (very consistant) Bass hammer bore length is 62 mm total length is 80 mm (also very consistant) Balancier (Whippen) leather thickness is 1.5 mm (a good deal of wear and tear here) Distance from hammer tops to strings is 50 mm String height from keybed in the 5 sections... bottom string and top string as follows: Action glide bolts adjusted so that they just barely make contact with the key bed. Stil there is a 1.5 mm gap at the action ends from the middle rail of the key frame to the key bed. Bass 62 mm / 65 mm Low tenor 60 mm / 62.5 mm Mid tenor 62 mm / 63 mm Mid treble 63 mm / 61 mm Top Treble 50 mm / 58 mm My thinking is that perhaps the knuckle (roller) diameter is to small. What are Petrof specifications for this part? In any case if I had 11 mm diameter rollers then I can solve the problem of the drop screws dragging on the underside of the pinblock. But I dont see how I can figure on getting the hammers to regulate only 45 mm from the strings. The pinblock is just to low for that. -- Richard Brekne RPT, N.P.T.F. Bergen, Norway mailto:rbrekne@broadpark.no http://home.broadpark.no/~rbrekne/ricmain.html
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