Two action questions

[Richard Brekne]

Jon Page wrote:

> At 07:29 PM 08/31/1999 +0200, you wrote:
> >Hi list
> >
> >I got two questions for you all relating to grand actions.
> >
> >#1.  From time to time I run into a so called quality grand sort (I wont
> >mention the name but it starts with a "P"  grin) that has an odd ball
> >problem regarding regulation. Basically said, unless the jack is
> >regulated waaaayyy back, the note will miss. I ran into this problem on
> >an action I just reworked, I had repacked the nuckles insureing a nice
> >round shape, took much care to regulate the return springs nicely,
> >height of the tip of the jack to repetition lever was set to play it
> >safe (I have had this problem before on other such grands) made sure of
> >basically everything.  Still, upon setting the action in the piano
> >fifteen or twenty notes miss. And try as I may to find a reason, the
> >only thing that seems to help is to set the jacks so that they are well
> >back of the back edge of the core of the knuckle. Jack tips are barely
> >beveled and this is taken into acount. I suspect action geometry..(It is
> >never all that good on these things). Any ideas ???
>
> Knuckles Too rounded(pointed?), pear-shaped is best
> Top of jack angled too much?
> Tight repetition lever pinning.
> Weak jack spring (butterfly?) or sluggish center.
> Heavy hammers.
> Wear ridges on knuckles, sand smooth, brush, burnish.

Nope.. all this has been carefully serviced. even changed all the repetion
lever centers, they move really nicely, firm but quick. Knuckles look like
brand new. Slick with teflon powder. Tips of jack got a coating of WinSlip.
(a kind of mac-lube), Heavy hammers shouldnt really do it as I think through
the problem, In anycase they are not heavy, if anything a bit on the light
side. The Jack is indeed angled a bit off inline with the core of the knuckle
and this is what made me suspect action geometry. Cant move the whippen rail
forward or the fronts of the rep.levers start rubbing on the hammer rail.
Almost nothing to go on going the other way as its set all the way back
already. Moveing the hammer rail out is a possibility but would require
refitting hammers. It sure has me befuddled. grin.


>
>
> >
> >#2. Brand new Yamaha C7.  Action is very well bedded, and regulated.
> >Still on hard play in the middle area, 8 or 9 hammers on each side of
> >the note being hit raise (hop) very noticible. Feels like the hammer
> >rail is moving. All screws are dead tight. Lots of power seems to
> >dissapear. Only happens in the middle section of the action..
> >Suggestions ??
> >
>
> Springy hammer flange rail, You should see what happens on and other well
> know make (which begins and ends with an 'S').
> Jon Page,  Harwich Port,  Cape Cod,  Mass.  mailto:jpage@capecod.net
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Any fix to this ?? its like... really really springy.


Richard Brekne.
I.C.P.T.G.  N.P.T.F.
Bergen, Norway