need ideas (follow-up)

[Newton Hunt]

Good work!!

Perhaps installing cleats all around the bottom panel and screwing it securely in
place.  This will make getting in to service pedals and retrieving dropped tools but
it may introduce an additional measure of rigidity.  

Screwing a 3/4" sheet of AB plywood to the whole back of the piano is not an
acceptable solution.  Too much volume reduction.

		Newton

kam544@flash.net wrote:
> 
> >...I'm going to take three pieces of hard rock
> >maple 1' x 4" x 57 1/4", locate them evenly
> >spaced from top to bottom and join the five
> >back posts together.  I feel confident this will make a remarkable change
> >in the stability...
> >Keith McGavern...
> 
> Dear Caut,
> 
> Well, the deed is done.  However, I could not find hard rock maple locally,
> so ended up using Red Oak pieces.  Also, the size of the pieces ended up
> being 1" x 3" x 57".
> 
> Results:  Not 100%, but definite significant improvement with room to make
> it 100%.
> 
> Note: Mark Cramer's additional comments and suggestions might be an even
> better idea overall from what I did, but I wanted to follow through with my
> gut feeling.
> 
> Here's the scenerio: I mounted two of the boards perpendicular to the
> backposts below the handlea thinking for some reason this would be the area
> most affected.  But upon reading two notes, one in the upper bass, one in
> the lower tenor, with the Reyburn CyberTuner there was more variance in
> readings when moving the piano in the classroom than I deemed acceptable.
> 
> So I mounted the third piece perpendicular to the backposts midway between
> the handles and the top of the backposts.  *This* made a considerable
> improvement over the two boards below the handles.  (I did move the piano
> about with reckless abandon   :-)
> 
> This leads me to believe that maybe putting the support from the handles up
> would actually make a better improvement than below the handles.  I'll try
> this approach next time if I do it on another piano.
> 
> As for this particular 1998 U1, I will either move one of the lower pieces
> up, or add a fourth piece between the two pieces and the one piece to take
> care of the remaining variance.
> 
> Trust this experience will help someone down the road like it helped me.
> 
> Thank you one and all.
> 
> Keith McGavern
> Registered Piano Technician
> Oklahoma Chapter 731
> Piano Technicians Guild
> USA