Leveling Keys in a Vertical Piano
Welcome to the blog! We thought this would be a cool way to share some of the things we’re currently working on with anyone who might be interested. We plan to update it regularly with repair tutorials, tuning technique and theory, breakdown of regulation steps, pictures of interesting pianos we come across and any other piano-related goodies.
So for today’s post, we’ll briefly discuss the process and importance of leveling your piano keys.
One of the many crucial elements of vertical regulation is key leveling or setting the height of each key at rest. This is done by adding or subtracting paper punchings on the balance rail which spans the length of the keyboard and provides 88 pins upon which each key sits and “balances”.
Between the bottom of each key and the top of the rail, there is a felt bushing to provide cushioning and a series of paper punchings to regulate the resting height of each key. Over time, the bushings/punchings become compressed and part of the regulation process involves replacing these parts.
A tool called - unimaginatively - a key leveler helps tremendously with this job by taking a measurement from a sample key and duplicating the height for the other 87 keys on the piano. Key height is sometimes provided by the piano manufacturer but often, you start with a general height and tweak it as you set other measurements in the piano, namely hammer blow distance (distance between hammers and strings with hammers at rest) and key dip (distance between top and bottom of key stroke).
In general, you want to make sure the bottom of the white keys are 1/8” below the top of the key slip. If they are too low, they risk getting caught on the key slip when depressed. If they are too high, they can knock on the bottom of the fall board. Each black key is then set approximately 1/2” above the white keys.
Not only will setting proper key height make all the other regulation steps easier, it’s the one adjustment you can easily make to the keyboard to make it look and feel like a brand new piano.