Here's something I made to make welding (mig) or beveling a pipe edge easier. It's a set of rollers that work in conjunction with the holes in my Certi-flat welding table.
It can accept any size pipe or tube from drinking straw size up to 6 inches or more! Alignment pins on bottom fit into the holes in the table which automatically sets them in parallel with each other. A set screw on each allows the rollers to move inward or outward as needed. They have 1.5 inch steel rollers that spin on brass axle shafts.