Intro: Grand Regulation and Voicing Prep

Bed so keybed properly supports keyframe. Memorize in-piano bedding and strike for precise setup on-bench. Order operations so steps don't undo steps. Space and travel parts to work vertically. Fit strings to vertical-at-strike hammers. And sample early for correct geometry, balance, and friction. These plus good height and good light make work enjoyable and fast. And this work fits without rework back in the piano. And provides for successful voicing.

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

Bed and Sample

With shanks off rest cushions and no excessive friction, bed with action fully assembled. Remove action return spring and sand out indentations in keyframe. If backrail or frontrail has a problem, follow the Grandwork Bedding Protocol. Otherwise, bed balancerail using WNG Keyframe Bedding Tool, pedals fully depressed.

Next, employ Keysteps to sample bedding and use a WNG Dip Tool for weighted kissing samples of strike (see Grandwork Sampling Protocol). 

Set Up

Fix action position on the workbench and shim frontrail and backrail to be stable. If no Custom Keybed, use shop scraps and double-sided tape for positioning and frontrail punchings as shims (mark where they are on keyframe). Adjust bedding platforms (with Custom Keybed) or glide bolts (re-set later in piano) to match sample keys to Keysteps. Then, set up Regulating Rack Templates to represent string heights along the strike line (recreate samples from piano) and set stops on Regulating Rack 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 assess 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 and pin hammer flanges (9 half-swings) and repetition levers (5 grams resistance at long end). Then, put parts back on and space hammers to Hammer Spacing Scale and whippens to 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 Hammer Square (strike provided by Regulating Rack). Finish by spacing hammers to Hammer Spacing Scale and gang-file straight-bored hammers.

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

For best results, use 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 tails. This custom work ensures all aspects of regulation and string-to-hammer mating work properly.

Level Keys and Regulate

Level keys next (on workbench), squaring and spacing as you go. Use straightedge on Keystep-supported leveling sample keys. Level sharps and naturals in the same passes, settling keys thoroughly before and after each round. Use topstack, not leveling leads (which don’t show the real level, are annoying to work with, and can discolor backchecks).

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

Regulate jack-to-knuckle position using end-of-section samples, an 18” ruler, and under-lighting with a Lighting Rail. Place the Regulating Rack set at hammerline (lights plugged in) just behind hammer crowns and wink hammers to set repetition lever height. Using Regulating Rack and Gauge Keys, set hammerline and letoff. Then, lift keys from the back to set double escapement and validate by checking drop (Regulating Rack set at letoff). Finally, refine aftertouch by adjusting dip and touch up backchecks, playing hammers into check off Regulating Rack Templates set at strike.

Weigh Off

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

Using the WNG Key Gram Weight Set, match downweight and upweight speeds for each key, choosing downweights and upweights that provide clear, positive motion (no need for topstack tapping). Apart from being fast, matching speeds reveals frictional irregularities, slower indicating too much and faster, too little.

Then, take a refinement pass as needed to polish your work…

Return to Piano

If glide bolts were used to set balancerail height on the bench (best procedure without a Custom Keybed), return them to correct in-piano positions with WNG Keyframe Bedding Tool.

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

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

If voicing is needed, the Grandwork System has all action structure and fit essentials in place, so voicing will go well.


For both technician and customer, results will exceed expectation. And this grows a confidence to sell more jobs - and to 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 both speed and accuracy. Win win!!