Frankenstein Project: Gross, moldy Stage SeventyThree to shiny new SixtyOne

[Matthias_H]

Hi!

I happened upon a rather gross, moldy, corroded 1976 Mark 1 Seventy-Three with the low-E tine missing and two broken pickups. All screws are white or rusty-red, and the case is so rotten and stinky I will have to throw it away and rebuild it from scratch, keeping only the leg inserts and crossbar plate. Seriously, this thing so moldy it will kill anyone who spends time in the same room. The functional parts will get an overhaul to my best ability. Hopefully I will get the keybed, keys and harp wood parts to become sufficiently mold-free with an ozone treatment.

Trigger warning: graphic violence to follow.

Since I've been looking for more of a Fifty-Four, but those are increasingly hard to find, I decided to chop the whole piano down to a lighter 61 keys. The unused pickups and tines will come in handy for spares, because who knows how many more are going to break soon. While I'm at it, I will replace the excessively sturdy/heavy harp cage with a partial aluminum frame, so that the final result should hopefully be a bit friendlier to my back.

What I can share with you today is completion of STAGE 1: the reconfigured action. I removed eight keys to the left and four to the right (amounting to 118mm and 47mm, respectively. The key topping from old low E has become a new un-notched high C.

Steps so far:

(1.0) Take keyboard out of case; remove harp. Remove keys that will go, and yank out their pins. Using hot air gun and sharp blade, peel off the top of low E key.

(1.1) Cut damper and hammer assemblies. Using a little metal saw and a cutter knife, I scored and broke off 8+4 hammers and dampers. Shorter damper assemblies were re-attached using new screws.

(1.2) Disassemble hammer/damper unit by screwing off left/right profiles. Cut 47+118mm off the damper and hammer rails using giant circular saw. This was scary because definitely a point of no return.

(1.3) Cut keybed using CNC mill. I removed 47 and 118 mm sections to the left and to the right of the keyboard, using a zigzag pattern for better re-attachability. Glue and clamp back together.
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(1.4) Reassemble action. Here seen without the new top on the high C.
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Next up:

STAGE 2: trim harp to new length; remove pickup capacitors and replace broken pickups; brush up corroded metal parts; adjust tines

STAGE 3: build new plywood case

Keep your fingers crossed.

[Matthias_H]

Stage 2:

(2.1) Harp chopping done; rewiring / pickup replacement next.
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[Matthias_H]

Stage 2 (electronics) completed but not a lot of visible difference, hence no pics.

Stage 3: new case.
(3.1) Plywood case (bottom half only for now) constructed and tolexed. You cannot view this attachment.

Stainless steel lid, custom namerail and cheek blocks to follow.