Piano quiz - wazzit for? answers...

[Conrad Hoffsommer]

Howdy,

Mr Hartman got what I think is the use of those little holes.

My deductions interspersed.

At 11:16 4/8/2004 -0500, I wrote:

>  1915 Mason & Hamlin "A".
>1 - About 4" from one end of each was a small hole (~1mm).
>2 - The rods are definitely designed to only be installed in one 
>direction. One end is flat, the other slightly rounded.
>
>The rods have been in the same orientation since before I got here in 
>1981, and since the pedals had never given me trouble before, I'd never 
>had to remove the rods - even to move the piano.  It appears that they 
>have been upside-down all that time.



>Which end is up?

The flat end goes up.

>Why?

That gives good solid contact with the trapwork levers.  The rounded 
(lower) end goes in the cup at the end of the pedal and allows for smooth 
movement through the pedal's large arc of motion.

>Which end do you think the holes are on?

Close to the top/flat end.

>What were the holes for?

As John said, to prevent the rods from parting company with the lyre when 
removed from the case for moving.

>Why was I able to quickly see the holes when I took the rods out of the lyre?

This was the fun part...  ;-}

Since the rods had been installed upside down, the holes were inside the 
pedal box and not visible. When I removed the rods to access the inside of 
the box, I saw two shiny wear patterns on what had been the lower part of 
the rod.  The one pattern was right where the holes are and they were quite 
visible.

When I turned the rod over and re-installed it, the shiny part closer to 
the end now was in the upper guide and the holes were easily visible a 
short distance below the guide.  Lifting a rod up showed that the hole 
disappeared into the guide before the lower end came out of the lower box.


Conrad Hoffsommer, RPT, MPT, CCT, PFP, ACS, CRS.
Decorah, IA

- Certified Calibration Technician for Bio-powered Digitally Activated 
Lever Action Tone Generation Systems.
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