On Apr 8, 2009, at 10:17 PM, Joe And Penny Goss wrote: > BTW Do you use those long reamers we sent you? Hi Joe, I use them, but not full length, and I don't draw them all the way through. [For the benefit of others, these are actually burnishers, I think a meter long, a full set of sizes corresponding to centerpins - straightened piano wire I believe, with tapering at the very ends for insertion into the bushings. The idea was to emulate the European notion of the long centerpin technique.] I found it too cumbersome. I cut them in half (one set at home, the other at the university), and what I end up doing is a rapid back and forth using six inches of the wire in the bushing. I experiment with number and speed of back and forth strokes to come up with a standard, when I am re-pinning up a half size (doing a full set). It builds up heat and packs the felt. Conceptually, I prefer this to removing material with a broach, as I think there is danger that the broach roughs up the fiber and increases apparent friction, which will reduce after the burnishing of playing hard. And I like the idea of conserving felt, and increasing firmness by packing it more. I am more concerned with firmness of the bushing than with actual measured friction, as long as the friction is low enough for the center to be truly free. It would also be possible to insert the larger pin, and then use a wetting agent for the whole set to pack the felt against the new pins. But that is a time delay, and a bit of a gamble as to results. You pick a wetting solution % and wait and see. If it was too heavy in water, you have to repin. If it wasn't enough, you have to rewet. "Heat burnishing" you can measure the results right away, and they seem pretty stable over time, better than any other procedure I've tried. Regards, Fred Sturm University of New Mexico fssturm at unm.edu -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/caut_ptg.org/attachments/20090409/53f9c414/attachment-0001.html>
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