On Jun 26, 2005, at 2:15 AM, David Skolnik wrote: > Patrick - > > I would echo Joel's reply, at least the part about rolling the pin > between files, as I haven't used the Pianotek reamers. I have done that in the past, and a roughened center pin (which is essentially what the Mannino broaches are, though done more nicely than I usually achieve by rolling center pins between files) certainly works very well for felt bushings. It's just that I imagine a microscopic view of the results to the teflon bushing, and doubt that the results equal or exceed factory specs for the bearing surfaces. > Drill bits won't work, at least in part because they are not accurate > enough, I would expect to mic any bits that I used > and, I suspect, because their main cutting edge is at the bottom, not > the sides. Huh? Certainly not the way I envisioned drill bits functioning -- do others agree with your evaluation of the way drill bits cut? > The ones I have (when I can find them) are copies of what Steinway > was using, at one point at least. Made by Johnson Carbide, 4 flute, > from .490" to .530" in .0005" increments. They worked well, at least > until they started to feel dull, but I never found a direct > relationship, that is, I would generally stay "undersize" with the > reamer in relation to the pin size, or sometimes find the need to > "cheat" a bit, by bearing, just a bit, to one side or another. They > were not cheap, and I had to have a minimum (10 sets) made. Don't ask > where they are now. Yeah, I bought a set of them back in the late 70s. Where are they now? A casualty of my center pinning tool box falling and popping open, tools and center pins everywhere, on some slushy New England driveway no doubt. On a broiling Sunday in Billerica, Patrick Draine
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