Re-pinning question

[James Ellis]

Ladies & Gentlemen:

Mary is right.  I know folks who use gun brushes for cleaning out the old
holes.  But as Mary says, there is a problem with variation in pin torque.
I'm convinced this comes from three sources.  1) The original pins were not
uniform in size in the first place, and they left holes of somewhat varying
size.  2) The new tuning pins also vary somewhat in sise, which compounds
the error.  3) The gun-brush technique does not correct holes that are out
of round and tapered at the top, and it does not deal with that shoulder at
the bottom of the hole.  The new tuning pins end up being tightest at the
very bottom, and some may hit that shoulder left by the old pin.

Roger Jolly mentions using drill bits to ream.  I have done this, and it
works.  The only problem I have with it is in finding a bit of exactly the
right size that will just clean up the hole, and no more, that won't take
off any more wood than absolutely necessary.  But it's a lot better than
some of those spoon bits with turned-down edges that can't possibly work.

If there is much interest here, I just might try designing that reamer I
have in mind.  If I did decide to do this, it would come in size increments
of 0.001 inch.  I'm not sure the demand for it would merit the cost of
designing and making it. 

Any opinions on this?

Jim Ellis

At 09:06 AM 3/12/03 -0600, Mary Smith wrote:
>>..question regarding re-pinning a block..
>>
>>I've always been under the understanding that if you are going to just
>>re-pin and re-string, you go up 2 sizes on the pins, correct?
>>
>>Not always?
>>
>
>Definitely not always. We often restring with just one size larger 
>pins here at UT. It very much depends on the condition of the block, 
>so you do have to decide on a case by case basis. The only thing that 
>bothers me about restringing with the original block is there is 
>inevitably some variation in pin torque. It seems unavoidable, and I 
>have tried reamers and etc. One thing we do with moderate success is 
>to brush the glazing off the inside of the pin holes with gun brushes 
>of the appropriate size (no jokes about how widely available those 
>are in Texas, please!). Even with that, there will be variation in 
>torque. But, it is better than not restringing because we don't 
>replace blocks in-house.
>
>Mary
>-- 
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