[pianotech] Repinning / pinblock replacement

[Delwin D Fandrich]

I'm not Joe but perhaps I can offer a couple of observations based on a fair
amount of time spent in several Asian factories.

 

For the most part the pinblocks used in Korean and Chinese pianos are of
adequate to good quality. Most of them use European beech (or some close
relative). Occasionally you'll find one with maple. The most common problem
I've encountered is-as you have guessed-drilling. Dull bits are common and
often freshly sharpened bits are worse than the worn, dull bits were before
they were sharpened. These pinblocks are often drilled using NC machines of
one type or another and Few of these manufacturers have spent the time or
effort to work out the correlation between drill bit geometry and drill bit
feed rates and rotational speeds. Combined with the common use of
"rolled-thread" (as opposed to "cut-thread") tuning pins the results are
sometimes less than desirable 

 

In all probability repining with decent cut-thread tuning pins-Denro, or
instance-will solve the problem. Try a couple of samples using just one size
over and see what happens.

 

ddf

 

Delwin D Fandrich

Piano Design & Fabrication

6939 Foothill Court SW, Olympia, Washington 98512 USA

Phone  360.515.0119 - Cell  360.388.6525

del at fandrichpiano.com  <mailto:del at fandrichpiano.com> - ddfandrich at gmail.com

 

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Chuck Behm
Sent: Monday, February 13, 2012 12:16 PM
To: pianotech at ptg.org
Subject: [pianotech] Repinning / pinblock replacement

 

>Dale,
Agreed. However, the "budget" won't allow it. 'Sides, it's not that
old...just sloppy manufacturing I suspect. I've seen so many of the Asian,
(not Japanese), pieaners, in the first year of existence, with marginally
loose pins. After 10 or so years they're just loose! Not sure why, so have
to chalk it up to something wrong on the manufacturing end. (Of course they
could be using some of that "Select Hardwood".<G>
That's my take on it,
Joe<

Joe, I've got a related situation I would appreciate your expertise on. I
don't (thankfully) work on many Asian pianos, but I was just called out to a
home in Des Moines to look at a Hamilton grand still under guarantee with
loose pins. My observation was that all the pins were uniformly loose -
averaging 15 inch pounds or so, but without any significant variation one
way or another. My best guess was that the drill bit was a bit dull, heated
up, and drilled the holes a little on the big size - therefore loose pins. I
told the factory representative that in my opinion, replacing the factory
pins with oversize pins would yield a good result.

Another tuner called in to give a second opinion recommended a whole new
pinblock, pins and strings. Long story short, the rep wants me to do the
work recommended by the second technician and is going to proceed with the
replacement of the whole works (I quoted a price for the total job which was
approximately 3.5X times that of repinning alone). I've been feeling that
it's overkill - I'll do the job but I've thought it was more than what was
needed.

In your thinking, maybe it's a good thing to take the factory pinblock out?
Just curious. I'll feel better if I know the work I'm doing on the piano is
beneficial. Or maybe I should just take the bigger paycheck and not worry -
it's not like I pushed anyone into this decision - just the opposite. Chuck
Behm

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