SonexBuilders.net

I have heard of the possibility of the failure of the factory cable that retains the canopy when open. It may be possible because the way the cable is stressed at the swaged point. I made a new "soft" system that is lighter and I believe more predictable to inspect for potential failure. It's made from one inch pilot chute lanyard from the local drop zone. A rigger overlapped the ends then stitched it. I used a soldering iron to burn the holes for the same screws that held the cable. I made a couple of aluminum covers that cinch it all down. Works great and does not scratch any interior paint...

Here's a look at the old cable unloaded...clearly stressed.

You just needed ANOTHER excuse to go to the DZ....


Robbie
Sonex 1517

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About to do this step and never looked at the details until now. Kip, I like your strap idea.

Do people really put a 3/16" AN525 screw through that 1/4" tooling hole in the turtle deck bulkhead per the plans? Seems like a really odd thing to do.. Worried about that hole getting worked really bad over the years. Anybody up-size it for a tight fit?

To 142YX
I used a bushing that was an 1/4 OD and a 3/16 ID with a flange on one end. Found mine at the fly market at Oshkosh last year.

The tooling hole does not seem to get stressed. There is just not much relative pressure on it and it's pretty strong. When my canopy caught the wind like a parachute, the canopy frame was bent pretty good and the plexiglas was trashed but the tooling hole un-fazed. I would not worry about it personally but a small doubler in the area may make some engineering types sleep better... :D

I think I remember reading about this before, but have experimenters already had poor misfortune with using a gas strut in lieu of strap? Alternatively, what would you think of a carefully designed over-center kind of strut to hold the canopy more rigidly in the open position?

Kip,

You seem to know what I need, right when I need it most. Went out flying last night and as I was pulling the cable to tip the canopy, I felt the sharp jab of frayed cable. At the end of the swag she is giving up the ghost at almost 4 yrs.
Good job.

Larry

Just following up...after two years the "soft strap" looks as new. Skydiving materials tend to be of high quality as much of it is TSO'd.

:)

LarryEWaiex121 wrote:Kip,

You seem to know what I need, right when I need it most. Went out flying last night and as I was pulling the cable to tip the canopy, I felt the sharp jab of frayed cable. At the end of the swag she is giving up the ghost at almost 4 yrs.
Good job.

Larry

GordonTurner wrote:I think I remember reading about this before, but have experimenters already had poor misfortune with using a gas strut in lieu of strap? Alternatively, what would you think of a carefully designed over-center kind of strut to hold the canopy more rigidly in the open position?

Linkage sounds like good idea, looking into that just went to top of my to-do list.

As to the original question on that over-sized hole. use large washers each side, tighten down with nut, then add the eye of the strap and secure with elastic stop nut left loose enough for eye to turn.

David A.