CP 70-80 regulation specs./Isaac

[Joseph Garrett]

Isaac asked: "Hello, list and listeners ,

Can someone give me a basic regulation specs for these Yamaha grand
electric pianos (key height-dip, letoff, stroke).

I wonder also if the hammer covering is leather or corfoam, as used on
other yamaha "leather" parts (If I am not wrong on that one !)"

Thanks

Isaac OLEG


Isaac,
Juuuussst happen to have a manual!<G> The manual says that the hammer
covering is "Rubber (urethane)(under-covering) + artificial leather". I
suspect that it is NOT Corfam, but something else. I have a bunch of it in
stock, as I rebuilt a CP-70, several years ago. It is still pliable and very
useable.
Specs.:
1. Dip: 10mm
2. Key height: "surface of white key - 64mm from shelf. Black key - 12mm
from the white key."
3. "Adjustment of up and downward movement of jack (to knuckle): 0.1mm -
0.2mm
4. Blow Distance: 40mm
5. Let off:  Bass: 2.5mm
                Middle: 2.0mm
                Upper Treble: 1.5mm
6. Damper lift: 1/3 to 1/2 of blow distance. (These are my notations
garnered during regulation.)
7.Drop: 2mm
8. Checking: Bass: 14mm
                   Middle: 13mm
                   Upper Treble: 12mm
It should be noted that some adjustments must be done with the top action
removed, while others are done "....with the upper unit raised". Many can be
done with the unit complete. I found that I had to make some special tools
to go down between the strings to set the parts to specs. I'll see if my
scanner will do it's thing.<G> I'll send that in a separate post.
Best Regards,
Joe Garrett, RPT, (Oregon)
Captain, Tool Police
Squares Are I
P.S.
I just found a "cheat sheet" of the actual measurements that worked!<G>
DW: Bass: 52g  Treble: 40g
Key height: 66mm
Hammer Blow: 45mm
Let-off: 2mm
Dip: 9.66mm
Check: 15mm