Rod and Tube Straightness Checker Tool

Have you ever had the need to check if a rod or tube is straight? Build this simple tool with a few 608 bearings to quickly and easily tell if something is even slightly bent. Simply place the rod across the bearings and roll by hand. If the rod is true you won't see the ends wobble when turned.

I made this tool for a friend who is a competitive archer. He needed a way to quickly check if his arrows were bent.

The only extra parts required are four 608 bearings (not rubber shielded so