Moulded Keytops, problems buffing

[hubert liverman]

This is a multi-part message in MIME format.

---------------------- multipart/alternative attachment

  Hi,John

  I have a motor out of a clothes washer that rotates at 1760 rpm. I put =
a chuck on the shaft and it works for misc small jobs. Yard sale season =
is at hand and you should be able to pick one up to try at very little =
expense.

  HubertLiverman
  Tuner/tech
  Opelika,Al

  Joe had mentioned problems buffing.
  I also have problems in this area.
  I had thought on a softer buffing wheel, but have been unable to find =
a source. The selections available at my suppliers, are limited.=20
  Any ideas?
  I had thought on slowing the wheel down. Would that help?
  John M. Ross
  jrpiano@win.eastlink.ca=20
    From: MICHAEL MORVAN=20
    To: Pianotech=20
    Sent: Sunday, March 06, 2005 11:50 AM
    Subject: Re: Moulded Keytops


    Joe,
        I agree with you 100%, thank you, it is wonderful that you know =
these things and are willing to share them. Molded keytops are all the =
same dimension within one set. Keysticks unfortunately are not (except =
for several sets of Yamaha keys I've covered that were within 0.004 of =
each other). I've found that most sets of keys differ in length, width =
and height. I have one set of keys I'm recovering now where the =
keysticks vary in width up to 0.065. This makes recovering them tricky. =
If you have a keystick wider than the top you will have to trim the =
stick, if the top is wider you will have to trim the top. Molded tops =
being the same width have the contours and radiuses "molded" into them, =
so if you trim this you will, as you said then have to reshape them, the =
radiuses and contour to match and yes, the dreaded buffing. I prefer to =
apply what I call custom tops. This is  similar to factory procedures in =
which you apply a separate top and front. If done this way one can trim =
the excess and shape the keys regardless of the inconsistencies in width =
and yield good visual results. I've found that buffing plastic and ivory =
both have there areas of concern, but I use different wheels and =
techniques for both with good results. On the topic of keytop materials, =
I'm pretty sure I have all of the material available within the states =
and offer them. I have also acquired material from Aug. Laukhuff and =
Otto Heuss from Germany as well as P&S organ supply from England. These =
materials are of very high quality and texture but expense prevents =
their wide use. I've noticed that piano manufacturers are trending =
towards thicker and thicker tops, this means replacement tops will need =
to be thicker. I actually have a stash of keytop material that is 0.105 =
thick, but very rarely use them. I am not adverse to machining down the =
keystick to accommodate a new top because I am doing it on milling =
machines with tolerances to within a few thousandths of an inch, and it =
must be done. If one measures a keystick at 0.970 and is putting on a =
top that is 0.075 than you machine the key to 0.895 and you have =
retained the original dimension. The original dimension must be =
maintained or there will be a regulation nightmare. In some cases I find =
that a keystick has been machined with little regard for tolerances, and =
then a corrective measure must be applied. Three choices exist, have a =
new keyboard made, use a thicker or thinner top (depending on which =
direction the error is made), or build up the keys. Two of these choices =
are very expensive. Keytop replacement is tricky and is a decision that =
should be well thought out. The keyboard is a major focal point of the =
piano, it is the interaction point with the piano and is the foundation =
of all regulation. It is a challenge to balance appearance, playability =
and economy. Joe, what do you mean by "stink in my shop?" are you =
referring to a particular glue or the smell of machining off old plastic =
and ivory?  Mike
      ----- Original Message -----=20
      From: Joe Garrett=20
      To: pianotech=20
      Sent: Sunday, March 06, 2005 1:03 AM
      Subject: Re: Moulded Keytops


      Michael Morvan said: "The quality of the keytop, quality of the =
=3D
      piano, quality of the rebuild, preference of the customer, =
knowledge and =3D
      preference of the technician and budget. Crappy "molded" keytops =
are =3D
      nice if applied properly, and three thousand dollars worth of new =
ivory =3D
      is "crappy" if not applied properly. Molded keytops have the =
advantage =3D
      of being inexpensive, uniform in shape and appearance, and =
relatively =3D
      easy to apply with minimal skill, tooling and yields fair results. =
 A =3D
      disadvantage is that many people feel that they are a cheap top =
and as a =3D
      result do not use them."
      Michael,
      What you've said, I agree with. However, it's what you didn't say =
about moulded keytops that concerns me.
      1. Moulded keytops assumes that all key sets are the same =
dimension, which they are not. Therefore, trimming is necessary. Here =
lies the rub, as trimming of moulded keytop material is far more =
difficult than other materials. Especially in making the key set look =
consistant and have a smooth feel under the players hands. Secondly, if =
you've ever had to (try) to buff out scratches of moulded key top =
material, (and I'm sure you have, if you do keytops for a living.), it's =
next to impossible, as the material is too soft and will "burn/gaul" =
when even light pressure on a buffing wheel is applied. I'm not saying =
it can't be done, but it's a royal pain in the patoot to do!<G> Lastly, =
my aversion to moulded keytops is that it is too thick, especially for =
many older pianos with tight tolerances of the piano furniture. This =
requires milling the keystick down. I am totally averse to this practice =
for many reasons. Some of the "moulded keytop material" from Europe is =
better as some of it is what we call "Plexiglass". This material can be =
sanded and buffed. It's still too thick for my eye.<G> I too do keytops, =
but as only part of my overall service to my clients. I used to have =
someone else do it, as I really don't like the stink in my shop. Out of =
frustration with others I've taken to doing it....stink or not.<G>
      Regards,
      Joe Garrett, R.P.T.
      Captain, Tool Police
      Squares R I
---------------------- multipart/alternative attachment
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/pianotech.php/attachments/29/95/e4/75/attachment.htm

---------------------- multipart/alternative attachment--