Wooden Socket (Oak) for the Tuning Hammer Wrench (L) for Piano Tuning:

[themaximillyan]

Wooden Socket (Oak) for the Tuning Hammer Wrench (L) for Piano Tuning: Is It Possible?

This work became possible only thanks to the collaborative efforts of Maximillyan and AI.
Introduction
There is an opinion that the socket for tuning hammers should only be made from metal. The rationale is that the significant physical loads on the edges of the metal pin during its rotation in the mounting place of the socket can only be adequately supported by a harder metal alloy to prevent possible “sticking” with the socket. In this article, we will investigate this assertion by developing a model for a socket made of oak and analyzing the physical properties of the material as well as the forces acting on the structure.
Design
Several components make up the design:
•   On one side of the socket, there is an internal M10 thread with a length of 10 mm, through which the socket is rigidly secured (screwed) to the standard threaded holder for the L-shaped tuning hammer.
•   Strictly perpendicular to this hole, on the opposite side of the socket, there is a notch for gripping the hammer, which has the following geometric parameters:
o   Socket diameter: 37 mm (0.037 m).
o   Socket height: 45 mm.
o   Hole depth: 12 mm (0.012 m), containing a conical notch with dimensions of 5.82 mm to 5.87 mm.
o   Diameter of the holder fitting: M10 (10 mm, or 0.01 m).
Manufacturing Process of the Socket
1.   The workpiece is shaped as a sphere or cube approximately 47 mm by 40 mm, and the area for the grip notch is processed at a 45-degree angle against the wood grain to provide additional rigidity. It is preferable to use well-seasoned wood, which is first soaked in regular male (morning) urine for several days, then dried at a temperature of 22 degrees Celsius.
2.   The workpiece is secured in carpentry vices, and one side is threaded with M10 (10 mm).
3.   The workpiece is flipped over, and a 12 mm hole is drilled in the center of the opposite side, where a conical notch with dimensions of 5.82 mm to 5.87 mm is created. It is advisable to start with a small pilot hole of 11.5 mm and use a file to shape the edges of the socket. While working with the edges, a standard piano tuning pin (6.9 mm) should be used for fitting.
4.   After holes are created on both ends of the workpiece, it should be shaped with a file and then sanded to achieve a cylinder with dimensions of 37 mm in width and 45 mm in height.
Calculation Parameters
•   Torque (T)
Torque arises from the action of force at a distance from the axis of rotation (in this case, the socket radius):
r = D_socket / 2 = 37 mm / 2 = 18.5 mm = 0.0185 m
•   Torque Calculation

T = F * r = 15.2 N * 0.0185 m = 0.280 Nm

Shear Strength of Wood
Oak has a shear strength (τ) ranging from 10 to 20 MPa. For our calculations, we will use the average value:
τ = 15 MPa = 15 × 106 Pa

Cross-Sectional Area
The cross-sectional area subjected to shear:

A = width · height = 0.018 m · 0.018 m = 0.000324 m2

Maximum Shear Force
The maximum force (Fmax) that the socket can withstand:

Fmax = τ · A = 15 × 106 Pa · 0.000324 m2 = 4860 N

Comparison of Applied Force and Failure Force
The applied force is 15.2 N, which is significantly less than Fmax:
Fapplied = 15.2 N < Fmax = 4860 N

Thus, the socket should not fail and can withstand such loads without significant deformation.

Discussion of Friction and PIN Rotation Possibilities
The coefficient of friction (μ) between the pin and the socket may depend on the surface finish. For oak against steel, we will assume:
μ = 0.3
Then the maximum friction force (Ffriction):
Ffriction = μ · FN = 0.3 · 15.2 N = 4.56 N

Torque from Friction Force
The maximum torque generated by the friction force:
Tfriction = Ffriction · r = 4.56 N · 0.0185 m = 0.0844 Nm

Comparison of Torque
Let’s compare the torques:
•   Torque from applied force: T = 0.280 Nm
•   Torque from friction force: Tfriction = 0.0844 Nm
Since T > Tfriction (0.280 Nm > 0.0844 Nm), this indicates that when the string is tensioned, the pin will rotate together with the socket.

Conclusion
Based on the calculations performed, it can be concluded that a wooden socket made of oak can effectively function as an element of the L-shaped tuning hammer for piano tuning. It can handle the necessary loads and provides reliable interaction with the hammer, preventing any “sticking.”
Moreover, to achieve optimal operation of the design, it is essential to take into account the operating conditions and potential factors such as humidity and contamination that may affect the friction coefficient. Ultimately, a wooden socket is not only capable of fulfilling its function but may also be preferable in certain cases over metal counterparts due to advantages related to light weight and corrosion resistance.

https://www.academia.edu/128473080/Wooden_Socket_Oak_for_the_Tuning_Hammer_Wrench_L_for_Piano_Tuning_Is_It_Possible

[themaximillyan]

In this article, we will explore the possibility of creating a wooden socket for a traditional T-bar, comparing it to existing metal counterparts, and determining whether it can serve as an effective alternative.
1. Description of T-Bar and Socket Construction
1.1. Technical Specifications of Standard Metal T-Bar
Dimensions: 3/8 inch T-Bar Deep Socket, 12 mm
Length: 300 mm
Inner Diameter: 10 mm
Weight: 314 g
1.2. Description of Proposed Wooden Socket
Material: Oak
Dimensions: Similar to the metal socket
Manufacturing Process: Shaping a wooden blank from oak with subsequent finishing to achieve the required diameter and depth.
2. Steps to Manufacture the Wooden Socket
2.1. Material Selection
Characteristics of oak
Available wood options
2.2. Fabrication
Tools and processes used (saw, mill, sanding machine)
Steps to shape the blank to the required size
https://www.academia.edu/128513724/Wooden_Socket_for_Standard_T_Bar_MYTH_or_REALITY