Cramped Tuning Pins

Some pianos, like this Heintzman console, have pins that are so close together that the strings actually touch.

Tuning a unison when the pins are this close, is a challenge, to say the least. Once you tune one string, then start tuning the next string of the same unison, the rubbing and friction of the 2nd string on the already tuned string, causes the already tuned string to change pitch.  It's really obvious when you are tuning the third string of a unison. The rubbing can cause your already tuned double string unison to go out of tune, and your beautifully pure unison is shot.  I'm sure you can imagine quite a lot of back and forth with this situation.  With some forethought, it is easy to tune these kind of pianos. Here are the steps to tune a unison that has rubbing strings in the non-speaking section, caused by cramped tuning pins.  1) Notice which two strings are the closest. (in our picture above, it is the right two) 2) Mute the unrubbing string (left string in our case) if you are using double string unison technique, or just mute the unrubbing string plus one rubbing string (i.e plan to tune one of the rubbing strings first). In either case, you want to tune the two rubbing strings as a pure unison. 3) Tune the 3rd string to the other two already tuned. The actual final pitch may skate around a bit because of the rubbing that was happening when you tuned the first two strings, but when you add the third, the pitch will stay because there is no rubbing (or much less) happening during the tuning. With this technique, you can easily tune pianos with cramped pins, without the frustration of having your unisons go out of tune while you're tuning. Good luck. Try it out and let me know how it goes. Mark