[header] How to make a marshmallow gun [title] Use a ruler to mark off six 5-inch sections of pipe with a black marker. [step] Then mark off one 8-inch section of pipe and cut the pipe at that mark, leaving you with one 38-inch piece. It's just easier to work with a shorter pipe. 
[title] Cut at the other marks you made to produce the required six 5-inch pieces and one 8-inch piece. [title] Get the two elbow-bend connectors, two t-shaped connectors, and two end caps.