[pianotech] The Z-Bar

[Delwin D Fandrich]

The Z-Bar® is Fandrich Piano Company's trade name for the curved bar seen on the
right of this drawing. It is fastened securely to the back assembly at the
treble end (just under the top ribs) and becomes increasingly more flexible
until it terminates under (behind) the upper end of the bass bridge.

 

I coined the name Z-Bar® because it is essentially a mechanical impedance
controlling, or matching device blending the treble, tenor and bass sections of
the vertical piano. 

 

Simplistically it is the mechanical equivalent to the electrical crossover
network found in loudspeaker systems.

 



 

 

 

 

 

 

 

 

 

 

 

ddf

| -----Original Message-----
| From: pianotech-bounces at ptg.org
| [mailto:pianotech-bounces at ptg.org] On Behalf Of Greg Newell
| Sent: May 29, 2009 5:07 AM
| To: pianotech at ptg.org
| Subject: Re: [pianotech] Modified L Scale with 5 note transition
|
| Please, what are Z bars?
|
| Greg Newell
| Greg's Piano Forté
| www.gregspianoforte.com
| 216-226-3791 (office)
| 216-470-8634 (mobile)
|
|
| -----Original Message-----
| From: pianotech-bounces at ptg.org
| [mailto:pianotech-bounces at ptg.org] On Behalf Of Jude Reveley
| (Absolute Piano)
| Sent: Thursday, May 28, 2009 2:17 PM
| To: pianotech at ptg.org
| Subject: Re: [pianotech] Modified L Scale with 5 note transition
|
| Here are the two versions I'm aware of:
|
| Z=(d²NLf)/.02078 published by Jim Hayes
| Z=d(NT(1+B))^0.5 published by Dave Roberts
|
| Nice work David. I like your approach to the transitions,
| although like so much else I would love to hear it to know
| for sure. This shape is very classic (Hallet & Davis did this
| but added wound trichords instead of bichords. I've got a few
| in the oven so I should have a better idea soon. My
|
| first transitional bridge was on my first RC&S project that
| Ron Nossamon designed for me about a year and a half ago.
| It's definitely an exponentially better piano than anything
| I've ever done in that class and turned me on to this
| wonderful world. Thanks Ron.
|
| Are you throwing in Z-bars and radial rib arrays on all the
| pianos you add transitions too?
|
| I've asked this a few times before, but what version of
| calculating inharmonicity are you all using?
|
| Finally, how do you attach a graph onto an email?
|
| Jude Reveley, RPT
| Absolute Piano Restoration, LLC
| Lowell, Massachusetts
| (978) 323-4545
|
|
| ----- Original Message -----
| From: "David Love" <davidlovepianos at comcast.net>
| To: <pianotech at ptg.org>
| Sent: Thursday, May 28, 2009 12:28 PM
| Subject: Re: [pianotech] Modified L Scale with 5 note transition
|
|
| >I think I took my Z formula from Roberts.  It's all
| calculated from the
| > string data, not from the board.  There are a couple of
| formulas for this
| > particular factor and nobody seems 100% satisfied with how
| the data output
| > relates to the actual sound produced.  Others may be able
| to contribute
| > more
| > to the formulaic issues.  I input the data so long ago now that I've
| > conveniently forgotten the headache I got trying to
| translate the formula
| > into spread sheet language.
| >
| > David Love
| > www.davidlovepianos.com
|
| 

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