image = Middle-holes.scad.png |designers = |date = |vitamins = |materials = |transformations = |lifecycles = |parts = [[Frames]] |techniques = |tools = |git = |files = |suppliers = |reversible = true

=Introduction= Frames of length 3, 5, 15, and 25 feature exactly centered middle holes. These are often used as pivot points for assemblies, hinges, steering and suspension linkages, etc.

=Challenges=

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=References=

Techniques