I want to know the translation of this sentence
I have seen this article on the web.
But I can translate this sentence into our language. (Korean)
What is the exact meaning of the sentence below.
The part I can not understand is this.
"One major issue I knew I would encounter was collapsing the piece with the punch/drift. I inserted a piece of hollow round stock I had lying around."
I attach the picture so that you can understand better the meaning of the sentence in the context. Please tell me the meaning of the sentence above.