Kranich and Bach 5' 7" Grand WNG Action Conversion |
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This grand action presented significant additional challenges beyond a standard WNG conversion. As many technicians know, the design of this action is such that you can't remove keys unless you remove the whippen rail (or perhaps by removing the backcheck). The cast action frame is one piece and is screwed to the keyframe underneath the keys. Furthermore it has upright style backchecks and an odd repetition springs making it very difficult to regulate. In addition, the whippen flanges are mounted horizontally on the whippen rail (the whippens and hammer shanks are slightly angled to follow the path of the keys) and the jacks are of odd design. Servicing this original action is nearly impossible and parts replacement is out of the question. Finally, the mounting of the hammer rail was such that the rail mounting screws were not visible from the top of the rail making it difficult to make a standard WNG scale tape. Many thanks to Randy Mangus (did a Chickering) and Greg Graham (a Kranich and Bach) for sharing, and perhaps going where no one has before. (Addl. Technician Specs at the bottom) Also, many thanks to Brett Dearing and Dale Fox of Sacramento who have extensive WNG Action installation experience. They helped me from taking any critical wrong turns (and much more) during this conversion. It should be also noted that this piano holds a tuning like a "rock" on the coast of Northern California and does have an interesting history within the family. And, it also has important sentimental value to the clients. All Pros and Cons were explained, in depth, with the clients. Technicians: This pictorial was created for the piano owners so that they could follow the progress. |
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| The first task is to make a wrap around let-off rack so as to accurately record the original hammer strike line, existing hammer spacing, position of hammer and whippen flange hole centers for notes 1 and 88, as well as other important measurements. |
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| Then we use the WNG Mfg. parts kit to make up a "mock up" mini action to determine proper parts that will make the action perform properly. |
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| Close up of the "mock up" mini action and frame. Note the horizontal whippen flange configuration just to the left of the bottom of the piano hammer. The key layout on this piano is such that the Hammers (and Shanks) and Whippens are slightly angled to the rails (not perpendicular) to follow the keys. Thus, a horizontal whippen flange is required. |
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| Here we are making risers on the keyframe to position the action brackets
to proper height.
Note that we have also made, and added, "stiles" connecting the back rail to the balance rail for added support for the risers. |
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| Another image showing the riser and action bracket. |
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| In this case, it was decided that it would be safer to make the Action
Rails and "build from the keys up".
If it were a normal action, (90 degree whips with vertical flanges and 90 degree shanks) I would have certainly opted for an assembled or unassembled WNG Stack. |
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| Another image of the Action Rails. |
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| Another image of the Action Rails.
It's beginning to come together. |
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| A pattern of the Hammer Rail flange holes is taken using the WNG Scale
Kit. This will be transferred to the new Hammer Rail for marking and
drilling.
Take note of this Action Frame. It is screwed to the keyframe underneath the keys! It cannot be easily removed for key service! |
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| A pattern of the Whippen Rail flange holes is also taken using the WNG Scale Kit. This will be transferred to the new Whippen Rail for marking and drilling. |  |
| Here, we are drilling the Hammer Flange rail which has been marked using the previously made pattern. |
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| Both the Hammer Rail and Whippen Rail have now been
drilled and we have remounted our test parts.
Note that, due to the original spacing, the hammer rail screw had to be
counter sunk to allow for mounting the hammer flange. This action bracket (rail mount) had to be custom trimmed with a grinding wheel as "real estate" for this bracket to fit within the key layout is at a minimum! |
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| Close up of the modified bracket. You can't really see it in this image but extensive grinding has been required to gain proper key and action parts clearance on this bracket. |
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| Now we have to modify the Whippens. This image shows a flange that
would be in a normal vertical orientation. However, due to the angled orientation
of the keyboard and action layout of this piano, we must remove the end of
the Whippen assembly so that the Flange can be mounted horizontally.
This requires a Renner Long Flange. |
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| This image shows how the Flange will be mounted horizontally. However,
this presents a new "real estate" problem in that there is not much room
for a horizontal flange when the piano hammer (and tail) motion is
considered.
So, in this image, we are drilling new screw holes so that we can trim the length of the flange to gain "real estate" for the proper motion of the piano hammer and piano hammer tail. This requires a Renner Long Flange. |
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| Now that we have drilled new holes in the flange, we can now trim
the length of the flange to gain more clearance for the hammer tail
clearance.
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| Sandpaper is placed on the hammer rail. S.O. P. |
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| Finally! We are ready to start assembling and pulling it all
together.
All additional parts are ordered and received. |
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| Boring the Piano Hammers |
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| Making the first cut on a "European" style hammer tail. |
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| Making the final cut on a "European" style hammer tail. |
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| Shaping the Hammer Tail. |
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| Now, back to the keys. We had to move the Capstans. In addition, we will need a slightly higher Capstan position so we are building up the keys a little for a higher Capstan position. |
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| Having marked a line for our new Capstan positions, we are now drilling holes to reposition the original Capstans. |
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| The Capstans have been installed in the new location and Capstan tops buffed to a high polish. |  |
| We have now installed the Whippens. These are the lower (left most) set of black parts (not sticking upwards). |
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| Now, we are gluing on the Whippen "Heels" to the Whippens in a position
(there are several choices) that will best fit the "Action Geometry"
that is desired for our end result.
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| Now, we have "hung" note 1 and 27 of the bass section of the hammers. We then tweak the hammer hanging jig a bit to "hang" notes 2 - 26. |
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| We have completed "hanging" the hammers of notes 1 through 27. The Bass section. |  |
| Here, we are using a drillpress to insert a backcheck into each key. |
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| This picture shows all of the installed backchecks. |
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| Back to the letoff rack for more action adjustments.
Note that the top section of hammers have not been installed. This section of hammers will be installed when returning the action to the piano for best positioning of hammers in the high treble. And, the piano is a 5 hour drive away. |
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| Here, we are installing the original hammer rest rail. It pivots which serves to also raise the hammers slightly when the soft pedal is used. This grand action does not shift during soft pedal operation. |
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| Before final regulation (action adjustments), we need to level the keys. |
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| Another picture to remind us that this piano design required horizontal
whippen flange placement which was never industry standard except with Chickering
and a few others like Kranich and Bach.
Yes, it allows the whippens to be angled, but the horizontal flange placement requires extra "real estate" which impinge on the travel that may be required by the piano hammer motion. |
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| As you can see in this image, there is very little clearance between
the hammer "tail" and the end of the whippen flange rail.. We are cutting
it close but we were just able to make it work.
Note: This is hammer note 88 and this top section of hammers is only "dry fitted" (see the thread and extra "shank" sticking beyond the hammer) as it is optimum to glue hammer 88 at the piano for best tonal sound. We were also able to gain a little more "real estate" by shortening the tail length by about 1/8" from standard. |
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| Finally, we are just about done!. A few more hours of final regulation
(actions adjustments) and the action is headed for the piano. It's only a
5 hour drive away.
Hopefully, Mr Murphy (as in Murphys Law) will have better things to do when the action is returned. But, that gentleman always has my upmost respect. |
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| Well, after a 5 hour drive, the action slid right in! Well, almost, but not quite. I did have to trim a piece of molding trim underneath the treble pinblock as the treble hammer rail screw was not recessed and was bumping into this moulding. The treble case was supporting the pinblock on a shelf so I am not sure why the moulding was added but I was able to trim half of this molding away to allow passage of the treble hammer rail mounting screw. It would have been better to also counter sink the treble Hammer Rail mounting screw. |
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| The clients are absolutely thrilled with the results! Not only the
feel of a regulated modern action but they immediately picked up on
the improvement of the tonal warmth from the new hammers.
The customer also understands that we accomplished nearly the impossible. |
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| Additional Technician Specs:
WNG Standard Hammer Shanks and Flanges Knuckles glued at 16.5 mm position.
Hammer Shank Length (Ctr to Ctr): 130mm Final action Ratio is about 5.7:1 Custom Whippens: Renner Long Flange, with Low Angle Jack. Heels not glued. 23mm Whippen Heels finally glued at standard 62mm position Ronsen Wurzen 14 Lb Felt Hammers Raw Tails
Final Hammer Blow: 1.75 in. Capstans moved about 12mm (Yikes!) Final Key Ratio: About 2:1 |
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| Technicians: Please feel free to contact me if you are
considering a KB WNG conversion and have questions.
Tremaine Parsons RPT - Sacramento CA Chapter tremaine@tparsons.com 09/04/2016 |
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