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need quick help with action specs for a Kohler and Campbell KCG-650 grand. I have already tried calling the Samick piano service department and no one there till the 25th.

Who knows the action spread and specs?

Why do you think the spread is incorrect?
Depending on how the action is regulating, I might be tempted to measure spread and keep it in mind for possible adjustment, depending ...

FWIW, the regulation specs are present already in the action.

Just have to know how to recognize them.

What is the symptom you are trying to address?

Well when I receive a piano with loose action rails from the factory I wish to check to get the spread correct since it has moved. The screws that hold the whippen rail were very loose allowing the rail to easily move back and forth. I also wish to check over the specs to make sure they are correct before the piano can be sold.

I believe I am correct in saying that the action spread is off.....

I've already made the general specs for most Asian pianos. 10mm key dip, 15mm checking, 2-3mm let off and 2-3mm drop but as you know sometimes the specs vary like 13-14mm checking for treble notes in Yamaha. Etc. etc...

josef, Call me at work tomorrow if you are able.

I'll post other related to this afterwords.

Sorry I was not able to get back to you. The piano had to be ready asap.

I set up the whippen rail to center the jack tenders to the let off buttons. The jacks were either too far back or forward and the rep levers hieght was all over the place too.... Checking was far too low and nearly no aftertouch. Numerous leaky dampers to add to the fun.

But what could be expected from a Samick product.

Pulling together a regulation on 2 or 3 notes that you can then measure the effect of trying a certain spread can be a good approach.

Shortening the spread will raise the leverage slightly, increasing touch weight and after touch.

OR, increasing spread will do the opposite.

4.4" seems to be used quite a bit and could be a good place to begin.

Have to watch that the position of the jack in the mortise does not get too close to the end one way or an other. There is an issue with the angle of the jack as it contacts the knuckle. Honestly, I can't remember the optimum angle. Someone here might know. Certainly, wrong angle, wrong feel.

Changing the spread really mucks with regulation. Using 3 notes for testing simplifies it a bit.

Having a lot of experience with regulation helps one be sensitive to the result of variations in spread.