Wurlitzer problem

[Jim Coleman, Sr.]

Hi John:

You are to be highly commended for putting your finger exactly on the 
cause of the string breakage. A lot of tuner-technicians do not recognize
this cause, but keep breaking strings.

Whenever I see this situation where the Bass strings tend to jump up 
over their coils at the pin, I immediately relieve tension only slightly
just enough to be able to tilt the coil so that it is parallel with the
angle of the string as it approaches the tuning pin. This in most all
cases will eliminate the string breakage. As you retighten the string, you
may need to persuade the coil to remain at that tilted angle. The greatest
stress on a string is at the point where it begins to wrap around the 
tuning pin. If it is also starting to ride up on a previous coil, this
causes an extra sharp bend in the wire which makes it more likely to break
as you add tension in the tuning process.

I don'tl believe there is a correlation between the string breakage and
the loose bridge pins. Softer maple bridges are the usual cause of loose
bridge pins, expecially when they begin to split out. I have seen pianos
with perfectly good tight pins where the dogleg angle across the bridge
was even greater than on a Wurlitzer. sugar Maple or Beech are the most
successful bridge caps. There is a chemical test to tell if the maple is
really sugar maple. Silver maple is not as dense or strong. Neither is
Southern maple.

Jim Coleman, Sr.

On Wed, 24 Feb 1999, John M. Formsma wrote:

> Greetings, List!
> 
> I am a relatively new subscriber, and a first-time poster, so I'll give a
> brief bio before my questions.
> 
> My name is John Formsma, and I live in Blue Mountain, MS. I have been tuning
> pianos part-time for several years, and have begun to tune full-time since I
> have taken over my father's piano tuning business. My father passed away
> this January. I am somewhat of a neophyte with certain repair and
> troubleshooting procedures, and this list has given me some good information
> which will be very useful in the future.
> 
> This particular problem may have been discussed earlier, and I can refer to
> the archives if that is the case. The last several Wurlitzer consoles I have
> tuned have had a common problem with bass strings breaking. These pianos are
> all in the 20-35 year-old range, and I have had from one to four strings
> break on each piano that I have tuned. Each string has broken at the coil on
> the tuning pin.
> 
> From what I surmise with my limited technical knowledge, there is too much
> of an angle from where the string leaves the tuning pin to where the strings
> pass over the plate, which "forces" the string to slightly wind itself over
> the coil. The only thing I can figure is that there is a stress formed at
> the point at which the string begins to wind over the coil which eventually
> causes breakage because the string has been weakened at that point due to
> repeated tunings. I have also noticed that the bass bridge pins for the
> broken strings were loose every time. I suspect a correlation, but am not
> sure what it would be.
> 
> I have repaired the loose bridge pins with epoxy, and replaced the strings,
> but wonder if there is a way to avoid this problem. Is this a design flaw
> with a certain vintage Wurlitzer?  Has anyone else had this trouble?  Any
> advice would be appreciated.
> 
> Thanks,
> 
> John Formsma
> 
>