Parametric tuning key for early English pianos

Early English/Irish-style pianos (~late 18th to early 19th century) often have tuning pins that are simply flattened at the top, often with a wide range of different sizes, both between different pianos, and within the same piano.  This can make tuning with a single hammer challenging.  As the strings are at lower tension, and pins require less torque, than a modern piano, this is an experiment to see whether a 3d-printed tuning hammer, allowing hammers for specific pin shapes and sizes, can be useful.

In initial tests, this has been working for me, printed in PLA with:

• 0.2mm layer height, 0.4mm nozzle
• 4 line walls, 35% infill (further internal walls in the shaft are provided by a very small hole running through it).  Note that strength and lifespan here is likely constrained by material hardness, and can likely be best improved by choosing good values for the pin thicknesses.
• No support, and skirt only (no brim/raft).

Note that the parameters used to generate the the STL file here work well for my hand, and one specific piano.  You will likely need to use the SCAD file instead, to choose parameters that will best fit your use.