Tuesday, October 15, 2013

Paraglider Wing Mount for GoPro

Want a GoPro wing mount for paraglider wings that can be made for under only a couple of bucks?

I used the plate that came in the GoPro retail box, which is a real, working mount, but which many people just throw away.  Hopefully you didn't, but regardless, the project can be made instead with a standard flat adhesive mount fixed to a piece of plastic cut from a VHS box, about 4" square.

I bought these ¾ cup magnets magnets from Lee Valley tools.  The part is 99K3905.
You get six cup sets for $4.80, of which you'll need four to complete this project.

The other advantage to these cups and the steel washers they will attach to is their countersunk holes, which allows them to be very securely attached to things using pan head screws or nuts/bolts. 

Any rare earth magnets could of course be substituted for these Lee Valley guys, but they would have to be mounted in some less reliable way than with nuts and bolts.

Each of these rare earth magnets comes with a countersunk steel base plate, and a shallow ferromagnetic cup that the magnet will fit into. "Cupping" these magnets has  the effect of focusing the magnetic field - increasing the magnets pull in one direction, while reducing the magnetic effect behind the steel base and sides of the cup.

A description of this effect can be found here, in the column “Making your magnets work harder.” http://www.leevalley.com/US/wood/page.aspx?p=40077&cat=1,42363#7

These cupped magnets alleviated some of my fear of having 4 strong magnets loose in my life, that might accidentally come near any sensitive electronics, credit cards and so on.  The mount when stored isn’t anywhere nearly as “hot” as uncupped magnets would be, as the field  around and behind the magnets seems very weak, but they cling to their steel washers tenaciously.  

To make the mounting plate, I just drilled a hole in the display mount that new GoPros come with, and  bolted on the magnets using #6 machine screws and acorn nuts.  Any square plate could be used, however, along with a flat adhesive mount, but the plate will free up your adhesive mounts for something else.
I used plastic from a VHS tape box to make the other side, and because I’m obsessive, I covered it with nylon fabric using contact cement.  The countersunk washers that are included with the magnets are held on with #6 bolts and acorn nuts from Home Depot to keep in line with the GoPro acorn nut aesthetic, and also, because the acorn nuts are smooth, and the mount could be worn against the skin if it was clipped to a T-shirt.
Using only four magnet sets feels like more than plenty to secure the camera to the wing.  Each one has a holding force of about 16 lbs, so the camera isn’t going anywhere, short of a catastrophic event of such magnitude, that the safety of my camera will not be foremost on my mind. Side view showing the cupped magnets attached to the countersunk washers.
Side view showing the cupped magnets attached to the countersunk washers.
                               And a view of the pilot from the GoPro and Wing Mount in action.