The oyabashira and mabashira were then carefully measured and marked with chalk for the position of the top and bottom horizontal rails. The top front part (about 45mm deep and half the diameter of the post) of the mabashira was first cut away to provide some support for the top dōbuchi, as shown below.
Note that the bottom rail is a one-third section of split bamboo with the internal joints shaved off.
The top and bottom rails were then fixed to the rear of the oyabashira and to the front of the mabashira using annular nails (the bamboo was first drilled to prevent splitting).
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