No Power Yamaha Experiment.

[Roger Jolly]

Yesterday I had some spare time, so I fooled around with a C3 Bedding.


I bedded front and back rails in the normal manner, then bedded the balance 
rail with the Yamaha lift and thump technique.

Out of curiosity I cut 6 thin slips of paper and placed them in line with 
the glide bolts under the front rail. All were frozen tight.

Then set the Davis key leveller so that I could see and measure movement at 
the key tip.

Then started screwing down the glides,  until I could just start to pull 
the paper slips out from under the front rail, then back off so the paper 
was just gripped by the rail.

On average the front of the keys were raised 1/16".  Without losing any 
contact points from the front rail.  No lifting of the back rail was observed.
The key level had moved a little, checked before and after with a 48" 
straight edge.

There was a significant improvement in tone, particularly in the treble. 
Cleaner sounding and more power.

Conclusion:  I think the key bedding was optimized. Will there be potential 
problems with humidity swings? Not sure, time will tell. But gut feel says yes.

Since I have been doing some work with action saturation, this has been an 
informative thread. No two action frames are the same, so making up 
definitive procedures, for bedding, key height, key level is not so 
straight forward.   Technique and aural training in this area is perhaps 
way under stated.

Now I back under my rock and grin ric.  There's lots of flex in those cross 
struts, this test I would consider conclusive.

Regards Roger