Double drilling - was Tuning pin choice

[Mike and Jane Spalding]

Ron, or maybe Roger??

One of you posted a year or more ago about how you take the edge off of the second "reaming" bit to make it follow the first hole.  I was unable to follow your description of which edge you touch up.  Would you mind repeating and clarifying, for those of us who didn't get it the first time?  Also, is the second drilling done in the same drill press setup as the first?

thanks much 

Mike Spalding RPT



----- Original Message ----- 
From: Ron Nossaman <RNossaman@cox.net>
To: Pianotech <pianotech@ptg.org>
Sent: Wednesday, February 26, 2003 7:34 AM
Subject: Re: Tuning pin choice


> 
> >FWIW, I have used the Diamond. I bought them BECAUSE they were more 
> >expensive (the standard theory being that I will screw up enough, might as 
> >well use the best materials - that might make up for some of my work). Not 
> >knowing which pins where like what, I was just hoping they were a little 
> >bit better in some way. I found that they varied in diameter over a few 
> >thousandths - so you need to mic them. I wonder if the threads are any 
> >different - as advertised - and somehow grip the wood better, or feel 
> >better, or the finish is better. Maybe they are better balanced for all 
> >you high-speed tuners!
> >
> >Terry Farrell
> 
> Dynamic balance! Hadn't thought of that. That must be it. Probably very 
> shiny too. I don't know that cleanly cut threads are particularly 
> beneficial, and I know over a few thousandths variation in diameter isn't. 
> I started using those snarly threaded Denros shortly after I switched from 
> the multi-lam rotary cut block to Delignit. I mic'd a few sets, and found 
> them much more uniform than the smooth and clean threaded Fly and APSCO 
> pins I had used previously. Double drilling the Delignit then indicated to 
> me that my previous drilling technique was considerably more responsible 
> for torque variations than were pin differences in the Denros. So I don't 
> mic the Denros anymore and still get better torque uniformity than I ever 
> did with the old block/drill technique/pin combination. That's good enough 
> for me, for now, until something about it offends me or I find something 
> else I like better.
> 
> Of course, the dynamic balance probably isn't as good as it could be, but 
> those perfect $400 tunings ought to take over 19 minutes anyway, and 
> anything under a 1/4 turn of the pin shouldn't set up any destructive 
> cumulative system resonance.
> 
> But then I could be wrong.
> 
> Case (as it were) in point: You know how grands wobble, sometimes 
> alarmingly,  when you're tuning them. Each grand, depending on it's mass 
> and leg stiffness, has it's own wobble impedance and resonance (with that 
> of the propped lid being somewhat different from the rest of the piano). As 
> tuners, we (at least I ) time our lurches on the tuning lever to minimize, 
> rather than reinforce, these wobble excursions. If we "tuned" our moves to 
> the resonant frequency of the wobble, we could quite likely bring a piano 
> to it's (and our) knees without breaking a sweat. To assess the 
> contribution of the dynamic balance of the tuning pins to this system would 
> require extensive lab facilities, an outrageously large grant, and more 
> than a few cases of a good wheat beer.
> 
> Meanwhile, we press on with the supplies available and do what we can.
> 
> Ron N
> 
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