Intro: Grand Regulating as Voicing Prep

The Grandwork System provides guidance and tools for piano technicians to succeed at grand regulating and simplify their voicing. Hammers address strings vertically optimizing repetition, power, and tone. And work done on the bench is not only faster but also easier to see, easier to access, and easier on the technician's body.

One trip to bench. A simple setup. Accurate regulating from key level to aftertouch. And the biggest time savings: no rework back in the piano!

In Dale Probst's words: "The Regulation Station brings grand action work out of the cave."

Bed and Sample

Make sure shanks are off rest cushions and samples have no excessive friction. Remove the action return spring and sand out any indentations in the keyframe. If the backrail or the frontrail has a bedding problem, follow the Grandwork Bedding Protocol. Otherwise, bed the balancerail using the WNG Keyframe Bedding Tool, pedal not depressed for now.

Next, employ Keysteps to sample bedding and use a WNG Dip Tool for weighted samples of strike (see the Grandwork Sampling Protocol). These will provide far more accurate setup references than traditional dip, blow, and letoff samples. When bedding and strike on the bench matches those in the piano, the work you do on the bench will be as if you did it in the piano.

Set Up

On the workbench, fix action position and shim frontrail and backrail to be stable. Set up the bedding to the Keystep bedding samples. Regulation Stations with a Custom Keybed make this easy! Set Regulating Rack templates to represent string heights along the strike line using the weighted kissing samples taken in the piano and set stops on the legs so all the way up is strike and all the way down is hammerline. On the templates at strike, record the hammer spacing scale and with the String Height Gauge, record end-of-section template heights.

With the assistance of Gauge Keys, fully regulate a natural and a sharp to validate specs, parts, and materials. Tweak geometry or make other changes while still chargeable as extras.

Remove hammers and whippens to an Action Tray, storing screws in order along the edges. File flared hammers with the Hammer Filing Jig. Pin hammer flanges and repetition levers as needed. Then, with parts back on, space hammers to the hammer spacing scale and whippens to the hammers.

Make Hammers and Hammer Travel Vertical

Set up the Squaring Platform (see Grandwork Alignment Protocol), traveling shanks to vertical with the Shank Traveler and squaring hammers to vertical at strike with the Hammer Square (strike provided by the Regulating Rack). Finish by spacing hammers back to the hammer spacing scale (also provided by the Regulating Rack) and then gang-file the straight-bored hammers, supported at strike by the Squaring Platform.

For installing new hammers, add the Hammer Hanging Jig to the Squaring Platform after traveling the shanks. Set up the hammers at strike and employ the Hammer Square Lite to square to vertical as you go.

For best results, use the Regulating Rack to measure bore distance (from strike to hammer centers) before boring hammers. Cut overall hammer length based on these measurements and bore from the tails. This custom work ensures that all aspects of the regulation and string-to-hammer mating work properly.

Level Keys and Regulate

Level keys next (on the workbench), squaring and spacing as you go. Keysteps, pre-set in the piano to be leveling samples under notes 1 and 88, support the straightedge for the naturals. Pre-level the outermost sharps and add a Keystep under each, turning them up to just touch the keys. Level sharps and naturals in the same passes, settling keys thoroughly before and after each round.

If needed, rough in any elements that are very out of spec (see the Regulation Protocol) and set dip to what your regulating samples indicated (to be refined later by aftertouch). Space backchecks and set naturals to check as high as possible without upswing tail-scraping. Set sharps to match naturals. And now that backchecking height is correct, set spring tension.

Then, set jack-to-knuckle position, regulating to samples using an 18” ruler and under-lighting with a Lighting Rail. Place the Regulating Rack set at hammerline (with lights plugged in) just back from hammer crowns and wink hammers to set repetition height. And set hammerline and letoff (measured with Gauge Keys). With hammers up, lift a key to match dropscrew engagement with jack tender engagement. Set drop to this sample, refining aftertouch by dip and touching up backchecking by playing hammers into check off the Regulating Rack.

Weigh Off

For some jobs, you are now done. But for others, you are ready to weigh off. This step adds further evenness and simplifies voicing. 

Using the Weighoff Kit, match downweight and upweight speeds for each key, choosing downweight and upweight combinations of a selected balance weight that provide clear, positive motion (no need for topstack tapping). The Kit easily converts criteria from consistent balanceweight to consistent downweight. Both systems employ the pick-and-add approach, where a pairing weight added to the upweight makes the downweight. Pick the pairing weight off and the key lifts the upweight returning the hammer to rest. Add it back on and the downweight engages the key lifting the hammer to letoff. Apart from being fast, matching speeds reveals any frictional irregularities, slower indicating too much friction, faster, too little.

Then, a refinement pass, fast and fun, a polishing of your work.

Return to Piano

Reinstall the action return spring, checking that its bearing surfaces are perpendicular and shimming with frontrail punchings if they are not. 

Re-bed the balancerail, this time with pedal fully depressed.

Then, settle wire, pitch-raise, and mate strings to hammers. This string leveling optimizes damper function, so fine regulate the dampers next, followed by pedals and trapwork.


For both piano technician and customer, the results will exceed expectation. And achieving these results grows a confidence to sell more jobs - and sell them for more money!

Full regulations are undersold today. Technicians find the miscalculations of traditional regulating expensive and the learning curve long. The Grandwork System reduces the experience needed to succeed at each step and its go-nogo methodology breeds speed and accuracy. Win, win!!