Pianos


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How Pianos are made

Piano keys were once made out of ivory.

This sought after material isn’t used anymore because it’s banned to protect elephants who were killed for their  ivory tusks.

Pianists now play plastic keys but the techniques involve the manufacturing a piano haven’t changed much and still rely on hand craftsmanship just like they did a century ago.

Beautiful music is a triumph but so is the piano itself.

 

Made of inner and outer rims, a soundboard, treble and base bridges over which the strings are stretched and a heavy cast-iron plate.

To make a piano rim automated rollers spread glue onto seets of hard rock maple coating both sides. Then they layer the glue soaked sheets sheets five to eight deep, depending on the model of piano

 

Workers feed the wet layers of wood to a rim press.

An impact wrench powered by compressed air turns the clamp screws.

The screws bend the wood into a piano rim form.

They measure the pressure on the layers with a torque wrench.

Steel arm’s reach across the wood holding this shape while the glue dries.

After twenty four hours workers loosen the machine’s grip, and the rim now holds its contour.

Now it’s into what’s called the conditioning room for more drying out.

The piano rims stay in this warm arid room for thirty days.

 

It’s time to make the bracing structure.

They place glued struts inside the rim, then apply pressure with the clamp.

The framework remains in this em brace for an hour while the glue dries.

This piano will have a tension resonator for extra support.

Steel turn buckles attach to a center hub

A worker tightens the turn buckles with a wrench,then he thumps it to make sure it’s tight and won’t rattle.

Next they’ll install the sound board made of spruce and the two bridges. strings will straddle the bridges and transmit vibrations to the soundboard, which is the amplifier of the piano.

A worker glues ribs onto the soundboard. He lowers wooden clamps over each rib to apply pressure while the glue dries.

That takes about an hour. Next he thins the ribs around the edges with an automated shaper cutter.

This will allow the sound board to resonate freely when the piano is played. Now they position the sound board in a bridge press.

Then they place a bridge locating fixture on top of the soundboard.

This device holds the bridge in place while it’s glued to the soundboard.

After the two bridges are glued down, they lower the soundboard onto the piano rim.

Then they push the cast-iron plate on to it. It’s a critical fitting, if they don’t get it right the piano will never function

Then the plate is removed for finishing. A worker cuts notches in the bridges which are now topped with a lubricant.

This very sharp chisel cuts through the hard maple like butter. Each notch will  ceadle three pianos strings, giving them the freedom to vibrate.

Now they roll glue onto the outside case of the piano, which is made of rosewood veneer on maple. They fit it snugly over the rim structure. A mechanical clamp holds it in place for an hour while it dries.

Then they stand the entire piano on its side. Spinning cutters shape the arms that sit next to the keyboard into an elegant

This is called a vertical stroke sander.

A worker runs it along the side of the piano to smooth out the wood.

After a black polyester paint is applied, they buff it up with this electrical cloth polisher. Then they hand rub a mirror glaze cream nto it, until you can really see yourself in this half finished piano.

To play a piano you need time to practice, and lots of money because a grand piano can cost about the same as a luxury car. And like a luxury car, when you lift the top of a grand piano you’ll see is that a lot has gone into its construction.

The bass and treble bridges are now fixed to the sound board of this half finished piano.

Then to add glamour, they spray gold paint on the cast iron plate.

The next step involves the pin block which holds all the stress

It bears forty five thousand pounds of tension from the strings and transfers it to the iron plate.

He drills into the maple pin block through holes in the iron plate over it.

The holes are for the tuning pins hence the name pin block. They unfurl pieces of steel wire from big coils.

Using a vice grip the worker twists the end of the wire into a neat loop.

Then he hooks it onto a hitch pin on the back side of one of the bridges, making sure it runs between the guideposts over the bridge. Now he threads the wires through another guide called a negraff.

Using wire cutters he snips the wire to the exact length that he needs.

Then he wraps the wire on the tuning pin, using a device called a stringing crank.

He taps it into a hole in the pin block.

Then using a pneumatic hammer, he drives the tuning pins into the pin-block.

Now the string stretches from above the bridge to the pin block.

Each string is under a tension of up to four hundred and twenty-five pounds.

Again a force that will be kept in check by the heavy cast iron plate.

Now he places little felt covered blocks called dampers above the strings to stop them from vibrating when a note is played.

Using pliers he makes parallel bends in the damper wire so they’re aligned.

He pounds the key frame, checking for gaps that could cause knocks under a pianists vigorous

He smooths out the gaps shaving off bits of wood with a strip of sandpaper attached to a handle.

Now another worker presses the piano keys in between steel guide pins that have been installed in rows on the key frame.

She uses an air cylinder to push the back check into the end of a piano key.

The back check is a piece of wood covered with feld and buckskin that will catch the piano’s hammer after it strikes a string.

It’s time to make those hammers. She glues the felt covered top onto a thin piece of hornbeam a species of very strong wood. When a pianist hits a key, it will catapult the hammer into the string and that produces a note.

Now she aligns the hammers to be perfectly parallel, using a plastic square as a guide. This is called squaring it up.

Next she sands the tale of each hammer with a file so there will be no sharp edges to damage the back-channel.

Then she attaches the hammers to the top of the keyboard with screws.

Now she places weights on each key and then gently taps the rail to get the hammers moving.

She’s testing the amount of effort it would take for a pianist to push each key down.

This is called the weigh-off. After she determines how much weight is needed she marks a place on the side of the key and drills one or two holes. She plugs each hole with a piece of lead.

In a process called swedging she pushes a divit into the lead so it expands and fit snugly into the key.

The lead will counterbalance the weight of the hammers and give the key the required amount of weight.

The technician checks each hammer in each key, making subtle mechanical adjustments so they move smoothly and fluidly.

It’s the piano’s first big tune-up. He fine tunes tunes to hammer action by using a let off tool to adjust the driving mechanism

The piano is now ready for the hands of a skilled pianist and the ears of an appreciative audience.