Adjusting wippen assist springs

[Phillip Ford]

>Ideally, I would like to see them do exactly the same amount of work for 
>each key. But that means a very well and evenly balance action to begin 
>with... which you are only going to get with Stanwood like proceedures.

This was my original thinking.  However, I noticed that the Renner turbo 
wippens don't have springs on the top wippens (although they offer a kit so 
that you can fit them yourself).  So their thinking apparently is to 
utilize more assist in the bass than the treble.


>I agree with your second, and think any leverage assist mechanism should 
>be limited to doing the job of maximum  5 grams of FW

This was also my original thinking.  This equates roughly to a 10 gram 
reduction in WW.  The wippens with springs engaged don't lend themselves to 
WW measurements using the typical Stanwood kit.  I made a simple jig on 
which to mount the whippens so that I could measure WW with the springs 
engaged.  My plan was to adjust the spring to reduce WW from roughly 18 g 
to roughly 8 g.  I also checked the angles of the wippen in the action at 
rest and at full keystroke and checked WW with the wippen at these angles 
on the scale using my jig.  The problem is that if you set WW at roughly 8 
g (in other words a 10 g spring assist) at the rest position, at full 
stroke the spring is providing no assistance at all.  So, during the 
keystroke you transition from a 10 g assist to no assist at some 
point.  This didn't seem like a good thing to me.  So, I was going to opt 
for setting and checking the springs to give some assist with the wippen at 
the full keystroke angle and taking what I got at the rest angle.  This 
results in a negative WW in the rest position (in other words spring assist 
is more than the WW with no spring - or in more other words the wippen 
would be floating in the air above the capstan (with no hammer weight on it 
of course).


>I measure in terms of FW.
>
>Cheers
>RicB

How are you doing the actual measuring.  Are you measuring the wippen (such 
as I'm doing with my WW measurements) or are you measuring at the key.  To 
me FW only has meaning for the key itself.  Once it's installed on the 
keyframe and the wippen is put on it you're measuring DW or UW.  Are you 
measuring differences in DW or UW for changes in spring strength?

Phil F


>Phillip Ford wrote:
>
> > To those of you who use wippens with assist springs,
> >
> > 1.  Do you adjust them so that they are giving the same assist on every 
> key?  In other words so that  WW (wippen weight) is the same for every 
> key?  Or do you adjust them so that the assist is tapering from more in 
> the bass to less (or none) in the treble?
> >
> > 2.  In my opinion, actions with strong spring assist don't feel 
> 'normal'.  What do you think is the limit of spring assist at which the 
> action might still have a normal feel?
> >
> > 3.  How you measure the amount of assist that you're getting?
> >
> > Phil Ford