Ron, These are great points that I wish I had thought out while at the piano. I focused on the balance rail and my peripheral vision took a nap. Your reasoning will help me take a better look to pinpoint the problem when I go back to this piano. Honestly, I don't remember the exact construction of the bed. I do remember it is not solid, but has, say three or four boards running bass to treble. My guess is that the keybed is of the stile and panel design. Also, I know that the deflection presents itself only at the balance rail and therefore, does affect dip. I discounted the balance rail as the "crowner" because it was screwed tightly to the bed and because it would have to be crowning down into the bed to produce the summer effect (zero dip). I thought of front-to-rear crowning of the bed as you did, but I remember straight-edging this (in winter but not summer) and seeing no real daylignt under the edge. I wish I had done this in summer. I also felt that a crown across the short dimension was unlikely (but maybe not). My conclusion was that the bed, (now I'm thinking at least the portion (panel?) under the balance rail) had to be crowning downward, taking the b.r. with it, along the bass-to-treble dimension when it saw the summer's humidity. However, I'm not ruling out that it could be bulging along both the fore-aft and side-side axes. Regardless, I've learned something here. I look forward to my next encounter with this piano. Thanks. Cliff Lesher Lewisburg, PA So.Central PA Chapter 170 Ron Nossaman wrote: > Is the back of the keybed attached to the plate, or floating? The keybed > warping along it's length - rising and falling in the center relative to the > bass and treble ends - wouldn't change the dip. Front, center, and back > rails would rise and fall together. It has to be warping front to back, or > the balance rail has to be going up and down by itself, to change the dip. > Doesn't it? How's the keybed constructed? Solid, laminated, stile and panel, > planks with gaps??? > > Ron
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