To get the most out of helmet lights, they should be leveled by direct their beams towards drivers. This Instructable will show you how to build a self-leveling mount which is compatible with Portland Design Works, Cygolite, and Planet Bike tail lights. You can also install this mount to panniers and backpacks or attach a camera to it. The bike light I used is the PDW Danger Zone Rear Light.

Step 1: Materials

2 - plastic strips
1 - 2" #6-32 bolt
4 - #6 flat washers
12 - #6-32 nuts
Cable ties
Angle bracket
Tail light

Step 2: Drill Plastic Strips

Drill the strips for the cable ties and the bolt.

Step 3: Attach Angle Bracket to the Clip of the Light

Make sure there is enough space for removing the batteries or accessing the button.

Step 4: Attach the Angle Bracket to a Plastic Strip

Step 5: Attach Both Cable Ties With a Bolt

You will need to use the nuts and washers in this step. To lock the nuts in place, tighten them in opposite directions with two pliers. This will form a hinge. Test to make sure that gravity will level the light.

Update: Four nuts were added in the center to stabilize it.

Step 6: Attach the Mount to the Helmet

Make sure that the light has a full range of motion. If not, you can trim the mount.