A Better Way to Regulate Grands


The Grandwork System provides guidance and tools for piano technicians to consistently excel at grand regulating and have success with their voicing. In particular, hammers address their unison strings vertically, making the strings mated to them horizontal at strike, optimizing repetition, power, and tone. In general, work done on the bench is easier to see, easier to access, and easier on the technician's body.

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

Bedding and Sampling

Make sure shanks are off their rest cushions and samples have no excessive friction. Remove the 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, pedals fully depressed.

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

Setting Up

Fix action position on the bench and shim frontrail and backrail to be stable - Regulation Stations Deluxe or Full Monte make this easy. Set Regulating Rack templates to represent string heights along the strike line and set the stops on its legs so all the way up is strike and all the way down is hammerline. On the template edges, record the hammer spacing scale at strike 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 needed changes while they are 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 to the Hammer Spacing Scale (also provided by the Regulating Rack) and then gang-file the straight-bored hammers.

If new hammers are included, set up the Hammer Hanging Jig on the Squaring Platform after the shank traveling and before the hammer squaring. Set up for installing the hammers at strike (again provided by the Regulating Rack) 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), taking end-of-section samples. 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 will work properly.

Key Leveling and Regulation

Level keys next (on the bench), squaring and spacing as you go. Keysteps support the leveling sample keys, which support the straightedge. 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 the 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 set spring tension now that backchecking height is correct.

Then, set jack-to-knuckle position, regulating to samples using a straightedge section-by-section and under-lighting them with a Lighting Rail. Place the Regulating Rack set at hammerline just behind the hammers (with lights plugged in) and wink the hammers to set repetition height. Now, set hammerline, letoff and drop (measured with Gauge Keys), and refine aftertouch by dip and backchecks 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 evenness and further simplifies voicing. 

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 any frictional irregularities, slower indicating too much friction, faster, too little.

Then, perform a refinement pass to the regulation as needed, fast and fun, a polishing of your work…

Back to the Piano

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

If glide bolts were used to set balancerail height on the bench (the best procedure without a Regulation Station Deluxe or Full Monte), they need to be returned to correct in-piano positions, an easy matter with the WNG Keyframe Bedding Tool.

Then, settle wire, pitch-raise, and mate strings to hammers. Since the resultant string leveling optimizes damper function, fine damper regulating is next, followed by adjustments to pedals and trapwork.

The Results

For both piano technician and customer, the results will exceed expectation. And ending up in the best spot with best results grows a confidence to sell the next job - and sell it for more money!

Full regulations are under-sold today. Technicians find the inevitable 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!!