[pianotech] Fwd: Hybrid pinblocks

[Gene Nelson]

The simple test we did I cannot really draw any definite conclusions from however, if you pound a pin down a bit in the old clunker, the bottom of the pin engages fresh fibers and gives more torque?
Also, one thing I missed was that our eval was turning the pin just to break the initial friction similar to tuning. As Ron pointed out there is the additional friction as the pin continues to rotate where the differences in materials plays a roll.
Gene
  ----- Original Message ----- 
  From: erwinspiano at aol.com 
  To: pianotech at ptg.org 
  Sent: Thursday, February 18, 2010 7:47 AM
  Subject: Re: [pianotech] Fwd: Hybrid pinblocks


  HI Gene
   I can't speak to the multi-lam flat sawn blocks specifically but I've studied this a bit as well and heres an interesting thing. Far as I can tell just about any tuning pin of 2 3/8ths length  only protrudes into  the block 1 inch. On the occassion I've used 2 1/2" pins due to a thick plate flange. Now what I notice is  a tighter fit not looser, so with quarter sawn blocks, reason says that more wood is in contact with the pin  and thereby more friction/torque. What's happening with your set up is rather counter intuitive. The process which loosens or modifies the pin fit in our expereince is turning not pounding deeper.  Also what do we sometimes do in old pianos to tighten the pins?....No.....Not CA glue...We drive them.
    Dale





  -----Original Message-----
  From: Gene Nelson <nelsong at intune88.com>
  To: pianotech at ptg.org
  Sent: Wed, Feb 17, 2010 10:01 pm
  Subject: Re: [pianotech] Fwd: Hybrid pinblocks


  Dale,
  Quite an elaborate press set up.

  One more thing about this has my curiousity.
  The brief experimenting that we did involved dilignit and multi lam from Piano Tech. One sample of each cut about 2"x4"by about 5/8" thick. Not glued together - kept separate.
  Double drilled first .25" then two 6.8mm holes and two 6.9mm in each sample.
  Drove 2.0 pins into each hole. Two were dirven in about half the length of the pin and the others driven in to a normal height of the becket above the block.
  In each sample the pins that had been driven more were noticably looser than the pins that had been driven less. Also, we did not notice any torque differences between samples.
  The message that I get from this is that the lower part of the pin in a normal thickness block - regardless of the material it is made with - will tend to be tighter than the upper part of the pin. I suppose that more wood fibers are being damaged in the upper part of the block.
  This is what led me to inquire how the hybrids are evaluated.

  Gene
  ----- Original Message ----- 
    From: erwinspiano at aol.com 
    To: pianotech at ptg.org 
    Sent: Wednesday, February 17, 2010 6:19 PM
    Subject: [pianotech] Fwd: Hybrid pinblocks





    Hi Gene
      Well every one was doing it.   No, no, no... I owe TerryFarrell the thanks for motivation as he made me one of the quarter sawn versions and it tuned so well I was duly impressed... and the Canadian Double blocks were getting so spensive!. I wasn't always satisfied with the fit either. And Why not keep the money in the shop?
     I wanted a more consistent block that tunes like a Yamaha. I despise tight pins and wanted to gain control over the process. I have used both the delignit block material and the bridge cap material. Both are just fine. The bridge cap material is about twice as many laminations which I like but it doesn't come in a long enough sheet to cover the length of an entire block So the seam is placed between the tenor and bass tuning pin fields.When I run out of the block material I may try that again. 
      The added bonus of a block that solve pin hole enlargement over time was a great feature. In many blocks the pin holes are dangerously close to the block edge especially in the  bass. 
      I buy and machine my maple. I'm very fussy about the grain consistency. I can get 8 or 4 quarter that has very tight and consistency grain. Much more so than what I was buying but that's always the value added feature of any customized work .I have found it about impossible to buy or order wider quartered material and although it may sound like too much trouble I can usually machine enough material for glue into up in double panels ready for pressing in about 4 hours. I made shop built clamps to edge glue the material
      I have not altered the drilling technique. It is however important as Terry said to test each block with test pins. Maple varies in hardness and some no. 2 pins will be too tight drilled at .257 and others better at .261.
       I went to the trouble of making an air hose press to do the glue up. It's been stiffened a time or two and now glues a really flat panel. Quite a learning curve doing it my way.
      Is it worth it?

      The outcome is far better than I hoped. Love tuning these blocks--
      Dale





    Hello,
    I am very curious about hybrid pinblocks and those that have made and used them.
    What materials were used, how did you decide on the materails and their proportions. 
    What was the intended purpose and did you achieve the desired result? 
    Did you alter your drilling technique for the hybrid?
    Overall, do you think the extra work was worth it?
    Do you use a bandsaw to fillet the different blocks and what size is it - virticle capacity for cutting.
    Thanks for sharing your thoughts.
    Gene

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