CNC Piano Restoration: Precision Pinblock Replacement – Part 1

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When replacing a pinblock in an upright piano, I often find it is one of the most challenging jobs in the restoration process. However, now that we have a CNC machine in our shop, we have the option to use the CNC machine to rebuild any damaged sections of the pinblock with surgical precision!

How CNC Piano Restoration Works

When rebuilding the piano pinblock, I will first digitally map the pinblock area by photographing and measuring the area down to a thousandth of an inch. Then using this data, I will create a CAD design of the replacement section, being sure to align every tuning pin hole with perfect accuracy. This will correct any inconsistencies of the original hand‑drilled layout while maintaining the piano’s original geometry.

Next, the CNC machine cuts a cavity exactly 1.5" deep for a delignit pinblock insert (which is a material far harder and more durable than what was used in most 19th-century pianos). I cut the cavity just .010" oversized to ensure a perfect glued fit. Cool fact: the CNC machine even pre‑drills the pin holes at the correct angle, so the pinblock is all ready for reassembly.

This process represents the best of both worlds—preserving the soul and craftsmanship of historic pianos while using modern CNC technology for unmatched precision.

CNC Piano Restoration: Precision Pinblock Replacement – Part 2

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Achieving the correct torque on each tuning pin is critical for long-term tuning stability. The drill bit size and drilling depth can make a difference if there is any variation. This is one of the reasons I love CNC technology so much, it allows me to control every variable to the thousandth of an inch!

I’ll drill a few test holes first, changing up the bit sizes and depths until I hit the sweet spot for torque. I’m usually aiming for somewhere between 100 and 120 inch‑pounds. Sometimes I’ll use two different diameters in the same hole to fine‑tune the grip. This is something that’s pretty much impossible to achieve consistently by hand, but with CNC precision, it can be replicated across the entire pinblock.

The machine runs through a programmed sequence with exact accuracy & switches between bit sizes to create precise torque balance. Once the test holes are complete, I will measure the torque in both directions to confirm the results. By adjusting depth increments, down to a few thousandths of an inch, I can find the exact fit that will hold the tuning pins securely without over‑tightening. This level of precision ensures that the restored piano not only looks great but will also perform reliably for decades to come. CNC machining has truly revolutionized how we approach difficult restorations, giving us a degree of control and repeatability that simply wasn’t possible before.

Watch the CNC machine work!

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Preserving Your Piano for the Next Generation

A piano is more than wood, strings, and metal — it’s a piece of family and musical history. By combining piano CNC restoration with our decades of experience as technicians and rebuilders, we can give your instrument a new life while preserving its heritage.

If you have a piano that needs restoration — no matter where you are in the U.S. — I’d be happy to talk with you about your options. We regularly arrange national pickup and delivery for restoration projects, so you can have the best work done without leaving your home state.

📞 Call our piano shop today to discuss your piano’s needs, request a restoration estimate, or arrange for a national piano move. We’re passionate about helping families keep their pianos in top playing condition for generations to come.