[pianotech] WNG jack don't come back no more, no more, no more.....

[Encore Pianos]

Good on Ya, Nick.  Your further elucidation gives more reason why going to
the extra trouble will bring these parts to the required level of
functionality, and allow the user to achieve the refined regulation they
seek, without being met with disappointment.  

 

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Nicholas Gravagne
Sent: Thursday, January 19, 2012 2:21 PM
To: pianotech at ptg.org
Subject: Re: [pianotech] WNG jack don't come back no more, no more, no
more.....

 

 

On Thu, Jan 19, 2012 at 11:18 AM, Encore Pianos <encorepianos at metrocast.net>
wrote:

 

..... 

Readers, Nick and I had a phone conversation about these parts about a year
and a half ago, where we shared our observations and solutions.  Nick, did
you end up repining the rep lever posts to a higher gram resistance reading?



Yes, but not all of them (long story). Repining the lever posts made a
noticeable improvement, but in my case I did not drill out / remove a cloth
"pin" as you did, but rather had to drill out the small "plastic" pin then
bush and pin the hole. The coil of the spring now fit snugly over the new
cloth and pin This anchored the spring and added a secure stability to both
free ends of the spring. No slippage.

 

I am in agreement with your observation about the zone of adjustment
acceptability being narrower than with wooden parts, although I would say
that it likely has less to do with wood than other design considerations.  


Yes.
 

The zone of adjustment acceptability in general is narrow with these parts.
Within those parameters, the parts can function quite well, outside that you
start to have problems.  Other good techs whom I know who have used these
parts also have come to this conclusion.  


Yes.
 

 

It is interesting to hear about the success of your shortening of the rep
lever half of the top spring, I knew you were planning on doing this but did
not know how it worked out.


It definitely helped in both performance and regulation-ability. But the
bend in the rep spring half (either before of after shortening) is not as
pronounced as in wood parts, being rather flat. This made tool use a bit
less comfortable. But all in all the bushed post and shorter top spring made
a noticeable and positive difference. A lighter gage wire would help by at
least allowing for a more pronounced and graceful upper bend as well as open
up the zone of adjustment acceptability and improved tool feel, but would
not necessarily kick the jack in the butt (couldn't resist:) with any more
power.
 

 If I had thought to do this back then, I would have done this at the same
time I had the springs out to increase the size of the barrel.  While I do
not have the direct experience of success that Nick has, I had my head
buried long enough with the problems with these springs to believe that this
is worth doing.  


Yes, though I wonder if replacing the springs with lighter gage all around
(supply house springs?) would be a good idea rather than fighting with that
"piano wire" spring.
 

For Ed Foote, I would make all my decisions about what modifications may be
necessary to improve and optimize the performance of these parts and take
the whips off the rails once and do them all at the same time.  It's a lot
less time doing them all at once, than finding out you need to do each
thing, one at a time.  I spent a lot more time going backwards before I
could go forward.  


Same here. I tried repining the jack; bought the expensive repining kit
(comes with instructions). This kit is not what we are used to and the
procedures are tricky, though with practice I'm sure a modicum of
proficiency would be had. The "pins" are needle bearing (nice idea) and the
increments change almost microscopically. 

So, as to the sluggish jacks. I would check the interface of the spring
insertion into the back of the jack activating hole. Is the engagement
length a bit too long. Is the angle of the entrance of the lower spring as
it approaches the jack heel to shallow or too steep. If too shallow bend it
to a more pronounced curve and readjust the spring for hammer rise. WNG and
Bruce Clark have a spec for jack grams movement; you may have to bend the
rules and pin it with less friction. This would mean, of course, gaining a
proficiency in the one task of removing all jack pins and repining same. Try
one, say note 88, and see what happens.

Nick 

 

 

 

 

 

From:  <mailto:pianotech-bounces at ptg.org> pianotech-bounces at ptg.org [mailto:
<mailto:pianotech-bounces at ptg.org> pianotech-bounces at ptg.org] On Behalf Of
Nicholas Gravagne
Sent: Thursday, January 19, 2012 11:50 AM


To: pianotech at ptg.org
Subject: Re: [pianotech] WNG jack don't come back no more, no more, no
more.....

 

 

On Thu, Jan 19, 2012 at 8:44 AM, Encore Pianos <encorepianos at metrocast.net>
wrote:

Will writes:

Combine the too heavy gauge of wire for the hammers with rep springs where
the coil flops around on a too small barrel (.050 difference) along with a
jack top that is visibly smaller in width and length than other comparable
grand jacks (the WNG jack is, and that means that the top of the jack is
carrying a much higher load than a comparable jack, 


Will -- a bit of nitpicking here, but the load has not changed; what has
changed is the intensity of the force (higher) and friction owing to the
smaller carrying surface area of the jack top. Your argument still
theoretically holds, however.

... 

My solution to these too heavy guage rep springs was to repin the rep lever
posts at about 10 grams to slow the karate chop kicks of the hammer from the
springs so that you would get a much slower and controlled rise.  The too
heavy springs make the adjustments hypersensitive and a giant pain in the
ass to regulate.  


Whether the rep spring wire gage is heavy or lighter, the same force from
either will be required to raise the hammer in the manner that most of us
agree on and with a concomitant and beneficial effect to the jack behavior
as well. "Too heavy" a gage, as I recall with my set, behaves exactly as you
say, making the "adjustments hypersensitive...". I recall that the zone of
adjustment acceptability was much narrower than we are used to with
traditional wood parts.

 

By the way, all this was on an early set of cloth bushed WNG parts made 2
years or more ago.  I suspect that in Ed Foote's case, some of these issues
may remain while others may have been addressed, as I had long conversations
with Bruce Clark about these issues some time ago.  

Likewise. It was my understanding that a lighter gage wire was being
considered. In my experiments with the rep lever half of the spring ----- I
shortened this segment and re-curled the top with rounding pliers keeping
the curl well within the rep slot. This shortened segment had to now work
harder to lift the hammer yet left a reasonable amount of tension in the
jack segment. BTW, my parts were all hard bushed.

NG
 

 

 




-- 
Nick Gravagne, RPT
AST Mechanical Engineering

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