I made this mount trying not to drill holes in the helmet and with the possibility to use it on both of my helmets ( mountain bike and ski).
I used a segment from a broken fishing rod made from fiberglass. You can use other materials (pvc, aluminium, carbon) .
For the camera I used the handlebar mount and for the counterweight I used pieces of lead wheel weights used for calibrating the rims. The counterweights are hooked together with plastic zip cuffs and mounted on the bar with a hose clamp.
I drilled holes in the bar at about 1/3 distance from the counterweights because is it is short and for the camera to be at a greater distance. You can find easily the center weight by sliding the counterweight on the bar. It’s not crucial to drill the holes so precise.
For the rotating part I used a swivel caster wheel with top plate, the smallest and cheapest that I could find (2$). In the middle of the top plate I fixed a nut with european standard thread with a thin metal plate and 4 small nuts and bolts. First I wanted to put also some glue, but it wasn’t needed anymore because the nut was fixed very tight.
A friend of mine made for me a bolt on a lathe machine with 2 different threads: one half with standard european thread to be screwed in the nut from the top plate of the rotating part, and the other part with thread for tripod. I couldn’t find anywhere a bolt or nut with thread for tripods.
This two thread bolt is screwed in the tripod adapter put upside down , which is hooked with an segment from the 3-way pivot arm that comes with the camera. And this segment is hooked to the flat quick-release mount.
The trick is at fixing together the pivot arm and the tripod adapter. I removed the nut from the tripod adapter. Then I took only the plastic handle from a short bolt used at the 3-way pivot arm and used with a long bold used for fixing the camera housing. And a washer, and that’s it.
Feel free to leave a message if you have any questions.