CadQuery制約メモ
Axis制約のデフォルトは180度逆転
The argument param defaults to 180 degrees, which sets the two directions opposite to each other. This represents what is often called a “mate” relationship, where the external faces of two objects touch.
なので、単に同じ辺をくっつけたいだけならparam=0が必要
例：result.constrain('body@faces@>Y', 'arm@faces@>Y', 'Axis', param=0)
Plane制約はAxis+Pointと同義なので、同じ話が適用される