Well, its only a bit of foam. Nothing ventured, nothing gained. Hopefully, I learned a little something in the process and the next one will be better for it.

 

Hindsight being 20/20, after having time to recollect what exactly did go wrong here, I now realize that a single step could have resulted in a different outcome had I done it.

I usually put a strip of transparent Scotch tape or Oracal vinyl across the edges of the ailerons and elevator, but I didn't do that this time. I relied solely on the hinge and a carbon fiber strip to take all of the forces being exerted on the control surface!

Being foam, the hinge can easily pull out of the control surface even when a carbon fiber strip is in place as it was on the elevator.

Looking at the wrecked parts I see that the carbon fiber strips also separated from the foam.

Taping the edges of the control surfaces also serves to make sure that all of the air flow gets directed across the surfaces and not in between the supporting member and the movable member.

On most of the smaller electrics we build, the forces of wind do not build up as high as they do on a nitro powered plane which can reach speeds upward of 50kts or more. The hinges typically don't rip out of the foam at the smaller planes because the forces exerted on them are less.

My first reaction was that I had caused the crash by adding an extension to the elevator at the last minute, but I now believe this crash would probably have occured even had I not done that.

Something to take into consideration on the next build!

 

Nice plane! I bet that wing gave you some fits! After reading your posts I had an Idea for a simple wing jig you could cut on the Phlat Printer. Just an Idea.. let me know

Attached files Wing Jig.skp (107.7 KB)Â

 

After doing a couple, I finally got the hang of it. The trick is to make sure you get a good straight trailing edge glued in place before you start laying in ribs.

The 1mm foam already has a curve to it, so it wants to form up pretty nicely with the ribs naturally.

I can see where the jig could come in handy. At least for one side. I don't quite see how it works when it come time to flip it over and do the other side.

But I like the way you did the folded foam to support the ribs. Pretty clever.