The Popular Mechanics website has a page with at-home construction plans for a 55-gallon drum smoker. Materials include a steel drum and plumbing parts that are available at a hardware store. Welding is not required to complete the project.
The set of directions includes a PDF containing a descriptive parts list. The construction process is explained and displayed in a seven-picture slideshow. Air intakes are assembled first, and the lid handle is constructed. A fire basket is made out of wire. Next the barrel is prepped for the other components, and the smaller pieces are attached. The smoker is then ready for business.