concert service Q & A

[Mark Cramer]

preparing for the Egré Competition this past week, I encountered
squeeking/groaning/ticking sounds while pressing certain notes slowly.

It wasn't the knuckles, (did the reference to "ticking" give it away?) it
was the repetition springs in their slots.

Three 3 years previous, I had polished the springs and
cleaned/burnished/treated the slots with a pencil, so there was no "gunk" to
deal with, just contact parts that needed service... fast!

Answer:

the answer was found in a tip Fred Sturm provided (as I recall it), about a
year ago:

"bend a wire-mute handle into a letter "J," with the point blunted, release
the spring, then use the hook to reach under and clean/burnish the slot."

I actually used a peice of music wire perhaps twice the diam. of the
springs, doubling it over for a rounded burnishing surface. Then, with
vice-grips as a tool-handle, lifted the balancier to the drop-screw, and
used a generous amount of burnishing force.

The idea being; to re-create a "work-hardened" round-bottomed spring-slot,
both wider and longer than the spring path.

It occurs to me now, if the pencil used 3 years ago was too sharp, I may
have actually created the grooves that were now causing noise/friction.

In any case, Fred's idea works very nicely, and very quick! The springs move
freely, quietly and faster than a one-armed paper-hanger! :>)

Question:

I'm having trouble with key-frame shift-pins; noise/friction from the
bass-side in particular.

I've squared the pin to the key-bed, rotated the pin to the last fresh side,
then finally ended up filing all four surfaces, rounding the aris's, then
fine-sanding, polishing and lubrifying.

I've re-bedded the key-block to provide no more than sufficient down
pressure, and rounded the pin-guide (brass) and finally burnished the
contact surface to a shine.

Everything was slick for the competition, however this morning it seems the
mild scraping sound has returned. When I remove the block, I'm afraid I'll
see the fine tell-tale abrassion marks again

Any long-term solutions?

Replace the shift pin(s)?

Re-fit the key-block to a Yamaha system?

Help?

Meanwhile, I'll go leaf through some previous PT-Journals, as this topic
kind of rings a bell.

thanks,
Mark Cramer,
Brandon University