Action Complex Gives Technician A Tension Headache

[Jgh71@aol.com]

Dear List

This article is a reprint from Hammertales, the Minn-Kota PTG chapter's
offical newsletter. As I was preparing to send this out ( I am the editor ) I
thought it would be  interesting to send to the list too. Hope you enjoy it!
Thank you.


P.S -  I have other articles from the Newsletter, would anyone be interested
in additional posts??

Joshua G. Harper
Harper Piano Service
Jhg71@aol.com
701-298-8216

Action Complex Gives Technician A Tension Headache
By Dennis Berryhill, RPT

I find adventure in the hunt for solution to problems. I was sent out on a
service call to check out a new Yamaha upright with double striking hammers.
When playing the softly  the keys were difficult to control amd the hammer s
many times would double strike. The customer was so unhappy with the piano
she was thinking of sending it back for another. At least one other
technician was unable to diagnose the problem, that only added to the
frustration. I felt this should be an easy and fast house call. First, I
checked the key dip and aftertouch. They eys had plenty of dip and a fair
amount of aftertouch. Hammer letoff was a good 1/8" All regulation
adjustments seemed to be set to Yamaha's specifications. So, if that was
true, why were the hammers double striking? THIRTY FIVE minutes later, I
tried playing the keys slowly ( for the millionth time) and then noticed that

the damper spoon was picking up the damper very near the same time as the
jack was starting to touch the let-off button. It was at that point the touch

seemed to get more heavy then I expected. If a note was played with a heavy
blow the whppen passed throguh let-off without casuing a double strike. On a
light blow the weight of the damper spoon picking up the damper slowed the
whippen enough to allow the hammer to continue on and hit the string and
bounce back hut the jack and again hit the string. Playing slow and soft
caused the double strike. I checked the tension of the damper springs and
discovered them to be way too beefy for me. I decided to relax thesion on one

spring to test my theory and it worked. I adjusted all the damper springs to
a lightler tension and the problem was solved. I have since seen this problem

in 3 other Yamha pianos. If you are having troubles with double striking
hammers and can't figure it out, try the damper springs, it just might be the

answer.

The cat, having sat upon a hot stove lid, will not sit upon a hot stove lid
again. Nor upon a cold stove lid. Mark Twain (1835-1910) American Author