Lower case key face reveal dimension

[shaweetz]

Hi folks,

I registered here hoping someone could help me out by measuring the distance between the key top and the edge of the case front on any model year.  How much key face is supposed to be revealed with the key up?

I have searched up the various nice 3d models for lids and bases that have been posted here over the years, but am not finding the exact info I need.

Rewind to many years ago, and I gutted the plastic keys and keybed out of an 83 MKII and inserted a wooden keybed, support blocks and wooden keys from a donor into the lower case.  The result of this plus all the cumulative action adjustments I did was fantastic.  At the time it got re-tipped, backchecks, a damper mod, and all the required levelling, easing, and strike line adjustments.

Unfortunately, the wooden keybed sits up a little higher, as the old aluminum balance rail etc was fastened straight to the case bottom.  So that left me with a gap under the key faces that I planned to resolve with a new bottom case.  Soo.  A decade+ has elapsed and it is time to finish this project.



Time to re-level it seems.

I plan to maintain the lid I have, which is a straight slash with no crook near the front.  So all I really need is that critical dimension.

Thanks for any help folks.

[shaweetz]

I should add that I will be pulling this data from the sketchup model that was posted here, and somewhere I might be able to dig up the vintage of the donor keybed I put in , but ultimately a verification from someone here would be great.  Hopefully those two numbers will agree.

1 9/16" from interior case bottom to that edge, from the model graciously posted here.

[pianotuner steveo]

I think what you are asking is what the key height is supposed to be?

That is measured from the front of the white keys to the bottom of the key bed, which should be a little more than 2". I don't know about the measurement you are asking about, however, that's not really a normal measurement.

[shaweetz]

It's not a normal application, since this key bed doesn't go with this case.  During the plastic years the case got shallower at the front, possibly by as much as 1/4".  So I have a gap under all the key fronts that I would like to close off.

[pianotuner steveo]

Yes, I understand that it is customized, but how would you fill in the gap? I suppose you could just take some trim like quarter round, paint it black, and attach in front of the keys, being sure that no white keys rub on it. This would be similar to a keyslip on a grand piano.

[rhodesjuzz]

Maybe you can take some kind of rod and cloth it with tolex so it blends in smoothly with the rest of the piano. There may be a dozen better options and tips from other people here with much experience. I am just a rookie

--Roy

[shaweetz]

I am committed to building a new lower case.  I just require the depth of the case that this keybed was originally mated with. 

Alternatively I just need someone to measure the nominal reveal on the key face of any arbitrary model year.  That is all.

[rhodesjuzz]

Ok sorry. I hope somebody can give provide you the proper data/dimensions to continue your job.

All the best

--Roy

[David Aubke]

You're probably referring to a model that I posted. I'm unclear what you're asking because you said you would take the dimension from that model. If you're wondering where the model came from, I have one from a 1973, 1974 and a plastic-key 1981. You're probably looking for the 1974.

If you're wondering about the accuracy of the model... it's pretty good. Maybe not perfect but probably to within a 1/16" or a few millimeters.

[pianotuner steveo]

Ok, I just measured this on 2 different pianos. The amount of white key showing, at rest, is 3/4" on one and 5/8" on the other. About 1/16" is showing on both when keys are pressed down.

Make sure the top of the key stays above the cabinet lip.  (When pressed down)

[shaweetz]

Ah, there we are, perfect.  Thanks.

If I pull that dim from David's 1974 model (1.5333) that leaves me with .817 of key face showing including the top, which just about agrees with PT steveo's measurement, if slightly more.  So I'd say you're correct that it's the right case for this keybed.  Thanks for looking into it, and also to David for modelling these up.

One might reasonably ask why I didn't just sell the MkII and buy a wood key model in good condition, rather than replace 80% of a plastic MKII with donor parts.

I was younger then.

[shaweetz]

You're probably referring to a model that I posted. I'm unclear what you're asking because you said you would take the dimension from that model. If you're wondering where the model came from, I have one from a 1973, 1974 and a plastic-key 1981. You're probably looking for the 1974.

If you're wondering about the accuracy of the model... it's pretty good. Maybe not perfect but probably to within a 1/16" or a few millimeters.

Mostly I am just unclear about exactly which model year my keybed comes from (the harp is original 82) and so unsure which is the 'correct' lower case.