Pad the Underside

As it stands, trying to strap something made from plastic and aluminium to the top of a helmet probably isn't going to be very successful, and is also probably going to damage said helmet.

Luckily a mate handed over the end of a roll of this self adhesive foam stuff. The roll (50mm) is the almost exact same width as the component box from Jaycar (53mm) so no trimming along the length is required. Cut a couple of pieces and stick them on for a surface with more grip and a less damaging finish.

See Rob's Homemade LEDs for more about this.