Bicycle Helmet Mirror for $2

Step 6 Make a groove for the wire frame

This part is a little tricky. Make a groove in each aluminum square. The aluminum squares will grasp the wire frame with these grooves. Cutting them by hand with a file is one way to do the job. Clamping the squares together and drilling between them is another way to do the job. It is faster, but the bit tends to wander and go into one square more than the other. If the bit does wander, some correction can be made afterward with a file. The width and depth of the grooves should be a little less than the diameter of the wire so the squares grasp the wire firmly.