Pianotech

Expand all | Collapse all

Jumping/sticking tuning pins

  • 1.  Jumping/sticking tuning pins

    Registered Piano Technician
    Posted 02-13-2025 20:14

    I'm dealing with a 110 plus year old pinblock in a Mason & Hamlin AA that has 4/0 pins in it. They are TERRIBLY jumpy and sticking making it almost impossible to do any fine tuning work. 

    Absolutely this pinblock needs replacement, however has anyone ever figured out for sure what causes this symptom? (I've heard theories). It's been a long time since I dealt with one this bad. Curious if anyone knows it's cause. 

    Peter Grey Piano Doctor 



    ------------------------------
    Peter Grey
    Stratham NH
    (603) 686-2395
    pianodoctor57@gmail.com
    ------------------------------



  • 2.  RE: Jumping/sticking tuning pins

    Registered Piano Technician
    Posted 02-13-2025 20:52

    I suspect that the tuning pin holes were not reamed prior to restringing with oversize pins.  I once serviced a 1857 Steinway concert grand that had the most awful

    jumpy pins. Nearly impossible to tune!



    ------------------------------
    Parker Leigh RPT
    Winchester VA
    (540) 722-3865
    ------------------------------



  • 3.  RE: Jumping/sticking tuning pins

    Registered Piano Technician
    Posted 02-14-2025 12:50
    When repinning an old block, one must clean out the old holes either with a reamer or I use a valve guide brush and sometimes a little bit of varnish in the hole before repinning. You could restring the piano with 5/0 pins or if the pins are already tight, you might be able to use the same size pins (after cleaning the holes) . Schaff sells tuning pins with a 2/0 tip but a 4/0 body.

    Sent from my iPhone




  • 4.  RE: Jumping/sticking tuning pins

    Registered Piano Technician
    Posted 02-14-2025 12:20
    Perhaps the tuning pin holes were glazed when removing the old pins?

    Joe Wiencek




  • 5.  RE: Jumping/sticking tuning pins

    Registered Piano Technician
    Posted 02-14-2025 13:38

    Several possibilities.

    1. The old holes are glazed.  Reaming in advance of installing new pins can help.  Not sure what you can do after the fact.
    2. The new oversized pin is bottoming out on the compression shelf at the bottom of the hole.  The first pin compresses the block when it's driven in.  That creates a narrowing of the hole at the bottom of the hole where the pin ends.  If the new o/s pin bottoms out on that narrower shelf you'll get tremendous friction there and that can cause problems. To avoid, drill out that shelf before installing the new o/s pin or use a shorter pin.  The fix would be to uncouple the string and back out the pin a bit.  Lots of work and danger of creating flag-polling issues.
    3. The new o/s pin is just too tight.  Going from a 2/0 to a 4/0 can sometimes create a problem.  Remedy is to back off the tension and then work the tuning pin back and forth 10 - 12 times (1/3 to 1/2 turns), until it loosens up.  


    ------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    ------------------------------



  • 6.  RE: Jumping/sticking tuning pins

    Registered Piano Technician
    Posted 02-15-2025 07:09

    David,

    Your #2 possible diagnosis is one I've never heard before but it now makes a lot of sense. I've never felt one as bad as this, and it being global from bass to treble is also rather unique. Thank you for this insight. Exactly why I posted this. 

    Peter Grey Piano Doctor 



    ------------------------------
    Peter Grey
    Stratham NH
    (603) 686-2395
    pianodoctor57@gmail.com
    ------------------------------



  • 7.  RE: Jumping/sticking tuning pins

    Registered Piano Technician
    Posted 02-16-2025 13:04

    Peter

    You might be able to test to see if that's the case by uncoupling one string and backing it out a full turn, or more, and see if that solves the problem.  

    I always drill out that shelf when installing O/S pins, if not use a shorter pin. Typically, when I go up from 2/0 I go to a lo-torque 3.5/0.  So first I just insert a #3 drill bit by hand (not attached to a drill--just to test the fit).  The drill should insert easily without binding on the side of the hole and you will feel where it bottoms out at that shelf.  Using a hand held drill, insert the bit without the drill on until it hits that shelf, then pull the trigger and just punch out that shelf.  That should do it.  If you are replacing tuning pin bushings, do that before you insert the bushings.  



    ------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    ------------------------------



  • 8.  RE: Jumping/sticking tuning pins

    Registered Piano Technician
    Posted 02-16-2025 13:56

    Thank you. I will retain this for the future. In this case there will not be any "repair" effort AFAIK as it really should get replaced at this point.  My re-pinnings also get the Lo-torq pins. They are the best IMO. 

    Peter Grey Piano Doctor 



    ------------------------------
    Peter Grey
    Stratham NH
    (603) 686-2395
    pianodoctor57@gmail.com
    ------------------------------



  • 9.  RE: Jumping/sticking tuning pins

    Registered Piano Technician
    Posted 02-27-2025 10:52

    What are Lo-torq pins?



    ------------------------------
    John Pope
    University of Kentucky School of Music
    Lexington, KY
    ------------------------------



  • 10.  RE: Jumping/sticking tuning pins

    Member
    Posted 02-27-2025 15:45

    Description from Schaff:

    "Patented Lo-Torq Tuning Pins allow restringing in the original pinblock using oversized pins, but keeping the head a tuning-friendly 2/0. Great for restringing entire piano or a bass section only."

    The head including the area of the string coil is the same dimensions as a 2/0 pin to avoid the coarser tuning feel of an oversized pin. I have no experience but the other day my mentor Gary Telleen described why he sometimes uses them.



    ------------------------------
    Trevor Penner
    Hillsboro KS
    (620) 877-0306
    ------------------------------



  • 11.  RE: Jumping/sticking tuning pins

    Registered Piano Technician
    Posted 02-28-2025 07:34

    There's an article in the PTJ somewhere that discusses the mechanics behind them. Great design.

    Peter Grey Piano Doctor 



    ------------------------------
    Peter Grey
    Stratham NH
    (603) 686-2395
    pianodoctor57@gmail.com
    ------------------------------



  • 12.  RE: Jumping/sticking tuning pins

    Registered Piano Technician
    Posted 02-28-2025 10:51
    The pins are also in between 3/0 and 4/0 diameter sizes, which can give a nice, not overly tight feel when going from the standard 2/0 pin.

    Joe Wiencek