Grand, ascr. Franz Jacob Späth c1770) Detail: Key fronts

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Step 1: Original instrument, Keyboard, bright upper (bone) and dark lower keys (ebony/ darkened pear).

Documentation: the lower key fronts are made of blackened pear (clearly identifiable under the microscope).

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Step 2: Original instrument, detail key front.

hypothesis of production: the groove profiles were cut/scraped in circular movement on a lathe, as full circles on a small wooden plate which is then halved.

 
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Step 3: a matching scraping tool is made by filing the groove profile as a negative.

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Step 4: After cutting and planing the pear wood plates to appropriate size and thickness (2 mm) the headstock is prepared for centering the pear plates to secure guidance for the scraper. 

 
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Step 5: Turning the groove profile under slight pressure.

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Turned pear plate with circular groove profile.

 
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Step 6: marking the half line.

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Step 7: Saw-cutting in halves along the mark.

 
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Steps 8, 9: Gluing the halved key front plates followed by filing side edges to match the key fronts.

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Step 10: Key fronts after finally being blackened with iron gall ink/caseine paint.

 
Tastenfronten Nachbau / key fronts replica
Tastenfronten Nachbau / key fronts replica
Tastenfronten Original /keyfronts original
Tastenfronten Original /keyfronts original
 
 
 

Details of reconstruction:

key fronts
key fronts

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