Methods of frictional coupling

A method of at least partially forming a second part for a coupling between a first part and the second part, the first part including a first surface having a first shape and a surface roughness average that is less than or equal to about 500 microinches (13 microns), the method comprising:

• forming a second surface of the second part, wherein:
• the second surface has a second shape,
• the first shape and the second shape are substantially complementary shapes,
• projections, forming at least a portion of the second surface, are arranged in a preselected pattern and are configured to produce an anisotropic friction fit, along an axis, between the first part and the second part when the first part and the second part are biased against each other with a predetermined force,
• the projections have an average elastic compressive range substantially equal to the surface roughness average,
• the average elastic compressive range is defined by limits of elastic deformation of the projections.

A method of forming a second surface of a second part for coupling with a first surface of a first part, the first surface having a first shape and a surface roughness average that is less than or equal to about 500 microinches (13 microns), the method comprising:

• forming the second surface having a second shape, wherein:
• the first shape and the second shape are substantially complementary shapes,
• projections, forming at least a portion of the second surface, are arranged in a preselected pattern and are configured to produce an anisotropic friction fit between the first part and the second part when the first part and the second part are biased against each other with a predetermined force,
• the projections have an average elastic compressive range substantially equal to the surface roughness average, and
• the average elastic compressive range is defined by limits of elastic deformation of the projections.

A method of forming a coupling between a first surface of a first part and a second surface of a second part, the method comprising:

• providing the first surface, having a first shape and a surface roughness average that is less than or equal to about 500 microinches (13 microns);
• forming the second surface, having a second shape, wherein
• the first shape and the second shape are substantially complementary shapes, and
• projections, forming at least a portion of the second surface are arranged in a preselected pattern and configured to produce an anisotropic friction fit along an axis, between the first part and the second part when the first part and the second part are biased against each other,
• the projections have an average elastic compressive range that is substantially equal to the surface roughness average, and
• the average elastic compressive range is defined by limits of elastic deformation of the projections;
• and
• biasing the first part and the second part against each other with a predetermined force to create the anisotropic friction fit, along the axis, between the first part and the second part.