Backpack Lower Exterior Hooks

This design is meant to attach a tool roll (or yoga mat, bed roll, etc.) to the bottom of a backpack. My tool roll is too large to fit in my bag with the rest of my drone gear, so I needed to mount it to the bottom of my bag.

I printed two of each of the hook and back plate in order to make this work.The plates are attached with five M4x16 screws, with two counter-tightened nuts on the backplate. It is very important to have something rigid to affix between the plates when bolting them together. In my build, I used some 1/2" aluminum stock from Home Depot that I cut to 12" in length. After filing down the cut ends of the bar, I slid them between a gap in the back plates before re-seating the screws to clamp the back plate firmly down over the bar. If no aluminum or steel stock is available, wood may be a good alternative material to keep the hooks aligned with one another.