How We Precision Bore Your Isaac Hammers

We use your samples or alternately, you can provide us with the following measurements:

String heights, (inches or millimeters) first and last, each section, height of strings from keybed (grands) at, or nearest the hammer-string contact point.

Hammer flange height from keybed or action bench.
It is difficult to measure this inside the piano with the action in.

We deduct the hammer flange height from the string height and add 1/16" measured from the striking point to locate the hole.  You've supplied us with the intended shank diameter and we have every drill size so we use the drill which will eliminate the need for you to ream and do a lot of fitting.  We calculate the position of the hole at both ends of each section.

Our Equipment Is Very Precise

If, as an example, there is 1/16" difference in the position of the hole between hammer #1 in a section and, say, hammer #30, we divide 62.5 (1/16" = .0625) by 29 (the number of changes in the section), and move our stop the appropriate number of thousandths to accommodate each hammer.

Our hammer angles can be changed down to 6 minutes of one degree.  We calculate the number of minutes between the first and last hammer in the angled sections and divide by the number of changes.  Every hammer between first and last is rotated the equal number of minutes so you get a precisely bored hammer and your regulation falls into place with a lot less work on your part.  It's just as easy for us to do things precisely and save you the extra work.

Once your hammers are bored the tails are rounded to the correct arc so that you don't need the heavy scouring of the checkering file, the hammers will check and hold because we use the necessary radius.  Tapering is the next step, the hammers are tapered equally of both sides half way up the felted segment.

Pre-Voicing

Most Isaac hammers do not require voicing, they will adapt themselves to the piano and the type of playing after being played
for two to three hours.

For special conditions or requirements, such as large halls, concerts, duo piano concerts (where the tone has to match), we will pre-voice your hammers to get the most energy out of your sounding board.  Please let us know your opinion of the board in question so we can match your hammers to your sounding board.

The Best In Parts & Accessories for
Your Piano

Ari Isaac
(416) 229-2096

e-mail:
isaacpiano@sympatico.ca