How to make tenons and mortises when three pieces of wood cross?

This tongue-and-groove technology originated more than two thousand years ago. It is said that when Lu Ban's father first made his debut, the master tested him on the topic of "Trinity Work Method". That is, three pieces of wood are combined into a "straight line", which can show different shapes from different angles.

That is, wood lining is mainly used as lining in the decoration process, which plays a role in stability and isolation. High-quality products should have regular geometric dimensions, few gaps and few dead trees. In order to ensure the decoration effect, dry wood lining should be used. Wooden battens can refer to some weapons and armor (cold weapon era), such as wood blade (wood blade Jr. was also called wooden battens in ancient times).

Crossing means that several lines or strips in different directions cross each other.

Mortise and tenon (s ǔ n m m m m m m ǐ o) is a main structural mode of traditional buildings, furniture and other appliances in China, and it is a connection mode of combining concave and convex parts on two components. The protruding part is called tenon (or tenon); The concave part is called mortise (or mortise).

It is characterized in that nails are not used on the objects, and mortises and tenons are used to reinforce the objects.