[pianotech] broken agraffes

[Horace Greeley]

Hi, Ron,

While I agree it's overtorquing, over time, I've had a number of the 
undercut-shoulder agraffes break, too.  That may be because I'm so 
often seeing a fairly wide range of years of production, and I do 
agree that most of the broken ones are from the earlier period.  I'm 
just not sure that it's possible to make a clean-cut on when it might 
no longer have been a problem.

One thing I am seeing again in more recent production is uneven 
agraffe height.  By that I mean noticeable/measurable differences in 
height between agraffes that would outside any kind of "normal" 
"curve" or line that might be expected.

Kind regards.

Horace


At 10:23 AM 1/23/2012, you wrote:
>On 1/23/2012 12:19 PM, Ed Foote wrote:
>>I don't believe all agraffe fractures are due to lack of thread
>>clearance, I have seen too many of the modern undercut design break. I
>>think it is mainly over-torque at the factory, trying to get them lined
>>up. Even with a "zone" offered by the more crushable lip, it seem they
>>still miss it by enough to occasionally over stress the studs.
>>Regards,
>
>Fine. I haven't seen any broken agraffes at all with undercut 
>shoulders. Every one I've run across has been as I described. In 
>either case, it's over torquing.
>Ron N