Why?

[Delwin D Fandrich]

Delwin D Fandrich wrote:

> Roger,
>
> I certainly agree with points 2, 3 and 4.  Unfortunately, I have not found
> their pinning to be all that consistent.  I think it is probably the result of
> the graphite used.  Since graphite is somewhat hygroscopic these centers seem
> to be somewhat susceptible to variations in moisture.  We've also had more than
> a few centers simply lock up tight after periods of hard play.  About point 5
> -- I do not consider hornbeam to be a superior wood compared to reasonable
> quality hard maple.  But it sure does machine pretty.
>
> Del
>
> ------------------------------------------

I've been told it ok to talk to yourself as long as you don't start answering
yourself as well.  So here I have to answer myself....

I was discussing this with my partner, Larry, the other day and he tells me things
have improved and that my information is out of date.  Back when we were building
the upright pianos we found that to get the required consistency we had to
individually test each Renner action center and sort them into groups depending on
their friction.  We usually ended up with between 20% and 40% that would test
good.  The rest were either excessively loose or tight.  The tight ones could
usually be shrunk down to an acceptable level, but the loose ones -- unfortunately
the larger group -- had to be repined.

This ratio carried over into the grand remanufacturing business, but has steadily
improved.  Now our action person still tests each center for friction but she is
repining far fewer.  Still too many considering the initial cost of the parts, but
Larry tells me the situation is much better than it was several years ago.  Things
are looking up.

Now if we can just get rid of that graphite!

Regards,

Del