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 -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://www.moypiano.com/ptg/pianotech.php/attachments/20120213/c8580104/attachment.htm>
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