Want to know how we tested our mounts for pull standards? How we tested for failure? Want to know how and why we set our pull test standards the way we did? Here we offer some information for the curious jumper if not just for the name of science and engineering!
PILOT CHUTE LOADING - HOW MUCH?
When talking with jumpers about quick release camera mounts, the question often comes up "How much force does a pilot chute exert?". That is a very good question and the answer can vary, as in a little to a lot depending on certain variables. Here, we have written a document explaining how pilot chute forces can be calculated when viewed as a dynamic pressure problem. These numbers may or may not apply to your particular situation. As stated in the document, there are a lot of variables. This also will help the curious jumper understand how we arrived at our testing standards for required pull forces. Theory is good and it helps us understand our world, but nothing can prove function more more than seeing it work in the sky. See our test jump videos below.
Theory is good and it helps us understand our world, but nothing proves more than seeing it work in the sky. Here is the video of a test cutaway performed at belly fly speeds.
Pull testing was conducted two ways 1) on a hydraulicly loaded press and 2) Installed on a helmet and loaded from a harness. Both tests were loaded to 110 pounds with the same pull force required at about 18 pounds. It's not included here, but the helmet fits snugly enough that, with the latch buckled, we can apply over 180 pounds of force to the mount WITHOUT the helmet slipping off of the plastic simulation head!
While safety is a first priority in terms of function and testing, we certainly don't want anyone losing a mount because of a broken or failed mount. We have performed dozens of tests under loads provided by hydraulic pressure to determine the break points of the mount. The mounts fail at 250 pounds of tensile stress (i.e. pulling up on the mount from the top) and 400 pounds of shears stress (i.e. hits from the side). In time we will perform similar tests on traditional mounts that are attached with adhesive. We suspect that they will not withstand the same stresses.