[pianotech] tuning pins

[Roger Gable]

I just drilled 2 holes in a sample pinblock stock. I drove a tuning pin in 
one hole with the Denro ( I think) which did not measure perfectly round, 
and the other with a Diamond. The Diamond turned smooth the Denro did not. 
There was a slight "snap" upon initial turning with the Denro. The snap was 
not enough to inhibit tuning, but demonstrated that a oval pin "jumps" 
around the hole. Why? My only guess is that the high point is pushing wood 
fibers outward, and this outward tension builds up and then releases. This 
is new pinblock stock and the conditions are as favorable as you could 
expect for a test such as this, but imagine what the possibilities would be 
on an uneven used block; a higher likelihood that the jumping could be 
intolerable. I switched to the higher priced pins a few years ago, simply as 
an experiment and found that I no longer experienced jumpy pins after 
"fighting" this anomaly for 30 years. As for the benefits of a set of uneven 
pins yielding a few larger pins to be used in the base area. Fine. Go ahead 
and measure all the pins. I simply purchase an oversize set and use them in 
the base area if needed.
Roger Gable

----- Original Message ----- 
From: "Ron Nossaman" <rnossaman at cox.net>
To: <pianotech at ptg.org>
Sent: Tuesday, September 28, 2010 7:52 PM
Subject: Re: [pianotech] tuning pins


> On 9/28/2010 4:09 PM, Terry Farrell wrote:
>> I don't remember what brand, but I have also noted new tuning pins that
>> are not round. But how do you conclude that slight imperfections in
>> roundness contribute to pin jumpiness?
>
> Thank you, that someone (anyone) besides me asked.
> Ron N