TIP, 생장추가 나무에 끼었을때 해결방법

Spanish windlass technique to pull on the increment borer
생장추 끼었을때 해결방법

When increment get jammed in the tree(specially oak tree in Korea),enabling removal of a stuck borer from a tree.Connect the rope around the handle of the increment borer and  a tree directly in line. (fundamentals of tree-ring research, page 86)

it is the very easy technique, but be careful.