keyboard levelling

[Thomas Cole]

justpianos@our.net.au wrote:

>Hi List,
>This question is obvious to me, but I don't know the history of innovation in 
>piano design.
>Has anybody tried a balance rail pin which screws in and out of the balance 
>rail, with micro-thread like tuning pins, to adjust it's height.
>
Every time I do a key leveling job, these ideas occur to me. To provide 
a screwdriver adjustment would be a big timesaver in the factory as well 
as the field, which could offset the additional cost of the parts, not 
to mention how makers would endear themselves to technicians.

I did see one 50+ year-old American grand which had a drop screw in 
front of the balance pin holes of each key. There were no punchings on 
the balance rail pins but the drop screw "heads" rested on a strip of 
cloth on the balance rail. The keys didn't need leveling but the whole 
job couldn't take more than 15 minutes to accomplish. If this method 
were retrofitted as described, one problem is that the key ratio would 
be changed. But it would work well if the keys were being replaced with 
new ones which incorporated this design.

Adjustable balance rail pins was discussed some time back. Since the 
pins also have to be bent left or right to square up the keys, you would 
need to repeat that procedure every time the keys were leveled, and then 
touch up the leveling, and then recheck the squaring... so I haven't 
been entirely satisfied with this approach. Even with that, it still 
would be faster.

I seem to remember somebody at Steinway working on this idea a while 
back but nothing has come of it to my knowledge.

Tom Cole