CAUT

Expand all | Collapse all

Boston Specs

  • 1.  Boston Specs

    Registered Piano Technician
    Posted 01-17-2018 15:30
    Hello all,

    I am confused about how to interpret the key height spec for Boston pianos.  Key height says 65mm in the Steinway/Boston spec list.  But it doesn't say where to measure from and to...  For instance, on Steinway pianos, the spec is from the cutout in the key bed to the underside of the lip of the key.  But Boston is a Kawai product - Kawai measures from the key bed to the top of the key (66mm).  Does anyone know for sure what if I should measure from the keyed or cutout and to the bottom of the key lip or to the top of the key?


    Thanks!

    ------------------------------
    David Pritchard
    Lynchburg VA
    434-841-7735
    ------------------------------


  • 2.  RE: Boston Specs

    Registered Piano Technician
    Posted 01-18-2018 13:04
    David,

    Key bed to top of key at front edge.  Kawai way.  Also with out glide studs touching keybed.  Would probably leave alone unless off a full 1mm  either way. Most loose some key height with a little ageing.


    ------------------------------
    Lonnie Young
    Petal MS
    601-270-6844
    ------------------------------



  • 3.  RE: Boston Specs

    Registered Piano Technician
    Posted 01-19-2018 10:52
    Wow.  I called Kent Webb and he said he thought it was to bottom of key cover....  

    How sure are you?  And why?

    Thanks!!

    David







  • 4.  RE: Boston Specs

    Registered Piano Technician
    Posted 01-19-2018 11:34
    Hi David, Lonnie has described "normal" on most pianos. One of us should look this up in one of the Action specs books. Mine is at Texas Tech right now-but I can look it up later, if no one else chimes in. I have the light blue one published by PTG (eveyone should get one of these by the way! Pianos techs I mean!). This book makes note of normal specs & shows asteriks for variations from the norm, etc.

    ------------------------------
    [Kevin] [Fortenberry] [RPT]
    [Staff Techician]
    [Texas Tech Univ]
    [Lubbock] [TX]
    [8067783962]
    ------------------------------



  • 5.  RE: Boston Specs

    Registered Piano Technician
    Posted 01-19-2018 12:09
    Hi All,
    Here's a link to the Kawai regulation manual on the Kawai website:

    It appears that 66-68 mm is the distance from the keyed to the top of the key.

    Happy regulating!

    All the best,
    Jon


    On Fri, Jan 19, 2018 at 11:33 AM, Kevin Fortenberry via Piano Technicians Guild






  • 6.  RE: Boston Specs

    Registered Piano Technician
    Posted 01-19-2018 21:58
    Yeah, I looked at the Kawai regulation manual and that is partly what confuses me.  Here's what I know:

    1.  The Boston spec for key height as listed in the "Steinway Worldwide Technical Reference Guide" is 65mm, but it doesn't say where to measure from and to.  In the actual regulation sequence for Steinway pianos, it says to measure from the cutout in the key bed to the underside of the key cover.  But it doesn't say specifically what to do with Boston.
    2.  Boston pianos are made in the Kawai factory, so it's possible that I should treat a Boston grand like a Kawai grand.  The Kawai regulation manual says to measure from the key bed to the top of the key and their spec for Kawai grands is 66mm.  (Remember, the Boston spec according to Steinway is 65mm, not 66...)  
    3.  I called Kent Webb at Steinway and he said he thinks it is to the underside of the key cover....  He didn't seem to be sure...
    4.  The Boston Grand I am regulating is about 2 1/2 years old with heavy use in a practice room.  The actual measurements at A0 and C88 were 64mm from keyed to underside of key cover and 65mm to the top of the key.  I figured I would typically need to add rather than subtract, so I went ahead and made the key height 65mm to the underside of the key cover.  I'm thinking that perhaps Kawai gave Steinway a spec number 1 millimeter less than their normal 66mm because they know Steinway measures to the underside of the key cover...  But Steinway also measure form the cutout... Arghhh

    I'm still in the process of regulating, so we shall soon see if where I set the key height will work in this piano.

    In the meantime, I think I will email Kent Webb and see if he can track down the actual answer.





  • 7.  RE: Boston Specs

    Registered Piano Technician
    Posted 01-19-2018 22:56
    David,
    While it is good to know what the factory spec is, what is far more important is function. The keys will function just as well up 2 mm or down 2 mm, as long as you are able to regulate to have adequate aftertouch. I wouldn't worry about trying to come up with the "truly official answer." It doesn't matter. The factors that do matter are things like let off, drop, jack to knuckle, rep spring strength, check distance . . . Key height is lowest priority when it comes to an actual spec. It's negotiable.
    Regards,
    Fred Sturm
    University of New Mexico






  • 8.  RE: Boston Specs

    Registered Piano Technician
    Posted 01-20-2018 16:03
    I completely agree with what you wrote, Fred. I also remember LaRoy Edwards emphasizing the importance of the Yamaha spec for key height. He basically said that regulation starts there and everything else follows. Maybe that was an old philosophy directly from Japan, because the Vertical Curriculum Book and the 37 Steps both include a section on how to determine key height from the piano.

    Bosendorfer is another manufacturer that stresses key height. I think they even have, or did have at one time, a spec that measured from the floor to the top of the key top. 

    Like many things in piano work, it depends on whom you ask.

    Richard West





  • 9.  RE: Boston Specs

    Registered Piano Technician
    Posted 01-20-2018 17:55
    Doesn't Bösendorfer set key height from the floor?

    ------------------------------
    Larry Messerly, RPT
    Bringing Harmony to Homes
    www.lacrossepianotuning.com
    ljmesserly@gmail.com
    928-899-7292
    ------------------------------



  • 10.  RE: Boston Specs

    Registered Piano Technician
    Posted 01-19-2018 23:20
    One other puzzle piece is that as I understand it the routed out areas of the Kawai Keybed that is also around the perimeter is slight variable for the purpose of adjusting keybed to string height for consistency.  Therefore you could not count on that area to measure from.  This is strictly my opinion it is nothing official by any means.  For what it's worth I set the two GP 193s that we have at 66mm and all seems well.  Also as always it has to fit right with the case parts which is the real "acid test"

    Happy regulating!!


    ------------------------------
    Lonnie Young
    Petal MS
    601-270-6844
    ------------------------------



  • 11.  RE: Boston Specs

    Registered Piano Technician
    Posted 01-22-2018 14:42
    From Kent Webb at Steinway:

    I have confirmed with the engineers that the measurement on Boston pianos (specifications based on our design which are not necessarily shared with any Kawai pianos) is from the lower level of the key bed to the underside of the key top.
    However remember that there is a +/- 1 mm tolerance so a particular piano could be anywhere between 64 and 66. If you have pianos that are operating well within this range, I would not change the overall key height but smooth out any irregularities and go with it.










  • 12.  RE: Boston Specs

    Registered Piano Technician
    Posted 01-19-2018 12:06
    Just to clarify a bit.  Looked into my Kawai regulation manual.  Measurement does not include routed area at font of keybed but does include top surface.  Most regular sized current models Kawai in very general terms 66mm.  I suppose I could post the whole sheet.
    One thing I learned also is to check all the screws on the bottom of the key frame first before leveling keys and such.  

    ------------------------------
    Lonnie Young
    Petal MS
    601-270-6844
    ------------------------------