We all need a third hand when taking photos for Instructables. I have an old helmet for cycling. My idea is to mount a camera on the helmet and use the camera's self-timer to release the shutter.
This photo shows the natural position of my hands and my head when working at my workbench as I might while photographing views for an Instructable. The photo was taken with my camera mounted on a tripod. I drew the yellow lines in MS Paint and held a protractor on the computer screen to determine the proper angle for the camera's field of view relative to a reference line on the helmet.
Step 1: Cut PVC
I wanted to use some PVC I will flatten and bend with a heat gun. I used five inches of PVC 1 1/2 inches in diameter.
Step 2: Make Kerfs
The center kerf runs the length of the five inch piece of PVC. The two kerfs on either side of the center kerf are 2 3/4 inches in length. I used a cutting wheel in an angle head grinder to make the kerfs.
Step 3: Flatten and Bend the Center Section
It required more than one step, but I used the heat gun to flatten the center piece. Clamping it between two pieces of wood while the PVC is soft is a handy way to work. Here I am heating the center section again so I can bend it back toward the camera a little. The piece being heated will attach to the helmet with screws.
Step 4: Check Screw Fit
If I were riding a bicycle with this helmet, I would not use screws that could injure my head in a crash. For standing at my workbench these screws I found on the road one day will be fine.
Step 5: Check the Angle of the PVC Bend
The "T" bevel square is set to 130 degrees. A piece of wood across the helmet duplicates the reference line in the Introduction photo. Mark the PVC's location on the helmet and/or heat again and tweak the bend.
Step 6: Screw PVC to Helmet
I used four screws on the center section for good support. Use the heat gun as necessary for a good fit. Here you see the heat gun in use to heat the side bracing before drilling and attach it with a screw. Do the same with the side brace on the other side. It is a good idea to check the 130 degree angle in step 5 several times as you proceed. Try to heat the PVC without melting or burning the helmet.
Step 7: Drill a 1/4 Inch Hole to Mount the Camera
Here you can see all of the screws holding the PVC to the helmet. The PVC is really quite rigidly mounted, which is a good thing.
I also drilled a 1/4 inch hole for the bolt that mounts the camera.
Step 8: Mount the Camera
Here you see the camera mounted to the helmet. I used a 1/4 x 20 cap screw with a wing nut. Turn the screw into the camera. Snug it up with the inverted wing nut.
Step 9: Actual Photo
This is an actual photo taken with a camera mounted on my old bicycle helmet. I have not cropped the photo in any way. The chin strap on the helmet should be as tight as possible to keep the helmet from slipping forward on your head due to the weight of the camera.
To use, engage the camera's self-timer and press the shutter. It is easier if you can find the self-timer button by touch. The duration of the self-timer is probably long enough that you could also set it and then put the helmet onto your head before the shutter fires. If you want to check your results, you will need to take the helmet off of your head, but that is not a problem.