help needed once again...
 

Ok so I'm building a sig sse. Well being I am sooo thickheaded I decided I was going to sh**can the hooks and rubberband to hold the wing together, and go with 1/4 - 20 blindnuts and nylon bolts. Well my fuse is almost done and I realized, (plus read it then, but really did think of it myself first) there is nooo way the sides of the fuse will take the amount of pressure the nylon bolts will put on them. Even if I widen the area with ply 3" around the bolt I still believe I will have problems. Do you think if I drill a hole in the nylon bolts and put zipties pulling the wings together will help? Or any other ideas? I drilled the 1/4 - 20 holes right where the hooks would have gone.

RE: help needed once again...
 

I wouldn't sweat the fuse side strength. It's doubled. There is a phenolic tube CA'd to both sides just behind the location of the "J" hooks or 1/4 x 20 bolt holes. There is a servo tray that is glued to the back of the phenolic tube, both sides and the former at the rear of the wing bay. There is a former just ahead of the "J" hook location.

Just make sure that the nylon bolts can't vibrate loose.

Did you add blind nuts to the insides of the root ribs? Or maybe a threaded hardwood block?

BTW- the stock approach is simply #64 rubber with 3 loops. How much "pull" does that rubber band exert anyhow?

RE: help needed once again...
 

Would you be able to post a photo?? Did you or did you not install wing hold down blocks??? Maybe I'm just having a brain fart and can't see it in my minds eye.

RE: help needed once again...
 

The 1st pic is of my current SSE. With the foward mounted throttle servo the "J"hook got turned upward.
The 2nd &3rd pics are of my second SSE. You can see the finished structure.

Oh - my 1st SSEused your technique - 1/4x20 nylon bolts. There is precious little room to get the bolt started and then threaded in. Imust not have gotten one tight before I bundled up the canopy hatch as during its 2nd flight of the day the nylon bolt vibrated out during a series of high rate full boogy rolls - a wing flew off after about 720 degrees. Imusta had a real stupid look on my face. No, I did not knife edge it to a landing pattern then roll upright for a 3-point landing.

RE: help needed once again...
 

I used the J hooks and a spring with loops on each end for my SSE with no problems, and installation at the field was quick and easy. It seems like you could modify that system to accomodate the 1/4-20 threads that you have already installed. Maybe 1/4-20 J hooks or thumb screws drilled to accept a spring. An added benefit of using the spring was that the wings could be removed from the plane and reassembled on the wing tube with the spring holding them together for storage as one wing unit instead of two smaller wings and a separate tube and spring.

RE: help needed once again...
 

Yes I like the spring idea, sure I'll be able to find 1/4-20 j hooks, thanks.
Nick