Grain Direction and Structural Strength

How the way the wood is cut and oriented decides whether a piece lasts, and the blank checks we never skip.

Wood is incredibly strong along the grain and surprisingly weak across it. For a long, slender object like a dildo, the direction of the grain decides whether the piece will last. Of all the checks we do, this is the one that happens before the lathe is even switched on.

Long grain is the rule

We orient every blank so the grain runs parallel to the length of the piece. That way the fibres run continuously from base to tip, like a bundle of straws, and the shaft can take bending loads without a weak plane.

Short grain and runout

If the grain runs diagonally across the piece (called runout), some fibres start on one side of the shaft and exit on the other within a short distance. That creates short grain: a section where the fibres don’t connect along the length. It’s exactly where a crack forms, especially at a narrow neck or at the base of a curve.

Curves

We turn curved designs like the Ember from blanks large enough that the whole curve stays within straight grain, rather than cutting across the fibres. It uses more wood, but it’s the only way we’ll make a curved shaft.

What we check every blank for

Checks: small drying cracks, often hidden in the end grain.
Knots: areas where the grain swirls around a former branch.
Pith: the very center of the tree, which is prone to splitting.
Ring shake: separation between growth rings.

If we find any of these in the shaft or neck, the blank is rejected. It might become something else in our workshop, but never a dildo.