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Locating strike line and bore angles

  • 1.  Locating strike line and bore angles

    Posted 02-10-2019 18:56
    Hello list,
    I am working on rebuilding a Steinway model H from 1893 (54" upright, with a laminated, bent rim inside the back frame.) I'm trying to determine boring distance as well as bore angles.  The parts that came with the piano when I picked it up were mostly original, it seems, with hammers (Steinway) replaced at some point along its path.  I did pull the plate and scrape the board and epoxy coat it (following a Del Fandrich article,) epoxied the original bridge cap, and re-drilled for new bridge pins. Also, the pin block (not glued to the back structure except at either end, but supported and "floating" on dowels, vertically,) was epoxy-consolidated and drilled (following a Ken Eschete article.)  Since I am using the original bridge cap, I had to grind the high treble nut down a bit in order to get positive down bearing there.

    In previous action rebuilds, I have used the WNG strike gauge (used to locate the strike point for hammers 72 and 88,) and had good success with that.  My question now is how to locate the strike point for hammer 1?  There are no dampers yet installed. The hammers currently on the piano, in the bass (1,26) have a difference of more than 2 mm from top of butt to top of hammer moulding, and a bore distance difference of more than 1 mm, which leaves me thinking that I cannot trust those to use as a guide, in addition to the plate changing position.  Perhaps, because the original shanks were maintained, it was just sloppy work, or intentional, I can't really know.

    One other question- is there a method to determine the bore angles based on string angles?  Usually I would have sent samples for hammer duplication, but in this case I'm quite wary of doing that.

    Thanks in advance for any help.

    Joe Wiencek

    New York NY

  • 2.  RE: Locating strike line and bore angles

    Posted 02-10-2019 19:50
    I have been using these ratios that Ed Mcmorrow developed, with excellent results:

    Strike points
    note 88 = speaking length (sl) * .064
    83= sl* .075
    78= sl* .085
    73= sl* .089
    68= sl* .094
    63= sl* .099

    #1 strike point by ear

    Jim Ialeggio
    Shirley, MA
    978 425-9026

  • 3.  RE: Locating strike line and bore angles

    Posted 02-10-2019 21:32
    I have found on several old S...way uprights that there are holes drilled in the plate on the bass end and treble end that if you put a nail in each and string a line it is the strike line. Note 72 still needs to be determined by ear but you get #1 and #88. Surprisingly close.​​


    Peter Grey
    Stratham NH

  • 4.  RE: Locating strike line and bore angles

    Posted 02-12-2019 13:19
    Thank you, Peter. I did locate the holes you described.  Note 88's hole won't give me a good tone (partially my fault, for grinding down a bit the nut,) but note one looks close enough to give me some guidelines.  I'll need to quiet the undamped strings to do the aural investigation.  Thanks for your help, and willingness to share your knowledge!