FT Explorer wing reinforcement question

[mrwis@yahoo.com]

I'm building three FT Explorers with friends presently. I saw one video of the wings folding and another post referencing that. I've got some carbon tubes and was thinking of trying to mount internal to the wing but given the dihedral they will have to be cut in the middle so I'm questioning rather that will help or if there is a better method.

Anyone have any suggestions on how best to reinforce the wing and/or if its even necessary. We will likely be building both wing types initially.

Thanks

 

[IFlyRCstuff]

one thing that ive done with dihedral reinforcement is to get a long aluminum/steel bar, bend it to the appropriate angle, then put in place at the cg.

 

[dropitlow88]

I have a carbon fiber arrow spar in mine with no dihedral and the difference in flight characteristics is nominal. If anything it's an improvement, inverted flies nearly as well as upright flight, very little stick input. Ditch the dihedral, it's a high wing plane so it will be stable anyway. I did and don't regret a single thing. It can be beat on like no other, full speed dive with full deflection pull out, snap rolls, high winds (so much fun!) and it will still slow right on down for slow flight and easy landing. highly recommend the spar with no dihedral, really instills confidence that it will stay together.

 

[dropitlow88]

I even took a few pics

 

[tictocdoc]

Folding wing

This actually happened to me. I wasn't flying hard. Still learning how to fly. Was taking it real easy. The thing looked like a wounded bird as it hit the ground. What I did (YMMV) was to buy some FLAT CF rod at my LHS. Unlike the round CF tubes, the flat CF rod can be bent to pretty much conform to the shape of the wing. I epoxied one to the top side of the wing and 1 to the bottom side. I covered them with "extreme packing tape" (stuff with the filament in it). Haven't made it back to the field to test it. Have tried to bend the wing up by hand. It's extremely stiff now. I think it will hold now. I hope FT addresses this issue with updates to the explorer design. It's fantastic other than that!

 

[AlSmith]

Put some fiber reinforced packing tape span wise on the top and bottom of the wing. Very strong, little weight.

 

[marc60]

I have a carbon fiber arrow spar in mine with no dihedral and the difference in flight characteristics is nominal. If anything it's an improvement, inverted flies nearly as well as upright flight, very little stick input. Ditch the dihedral, it's a high wing plane so it will be stable anyway. I did and don't regret a single thing. It can be beat on like no other, full speed dive with full deflection pull out, snap rolls, high winds (so much fun!) and it will still slow right on down for slow flight and easy landing. highly recommend the spar with no dihedral, really instills confidence that it will stay together.

I totally agree to that. I did the same on my Frankenstorch plane. I used the plans from the FT storch to build the wing. But made the wings without dihydral, flies great
http://forum.flitetest.com/showthread.php?19976-The-frankenstorch-plane

Greets Marc

 

[nerdnic]

In my wings I use a short piece of flat aluminum standing on its side sandwiched between the foam spar. It's strong enough to barely even flex on a 1500g plane doing a 120mph nose dive into full elevator deflection pull out. Costs 3$ at lowes and only adds about 25g to the plane. The wing is strong enough you could almost sit on it.

 

[Mostly Harmless]

Thanks for the info! Great stuff, as I've just started building a 2 meter wing for the Explorer, or my Explorer XL

(http://forum.flitetest.com/showthread.php?23584-Hybrid-plane-Explorer-XL-(Frankenplane-is-getting-overused)-)&highlight=Explorer+XL)

I'm looking for something that'll has a good bit of "float" to it. It has the basic design of the trainer wing, but with a dihedral and large-ish ailerons (or flaperons, if warranted).

I've been puzzling how to reinforce the wing and keep a dihedral, but based on the above discussion, I'm going with the straight wing.

Nic; Impressive wing design! Did you just use a 3/8" wide aluminum bar glued on edge within a "c-fold" spar? Or are your spars wider than 2 sheets of foam? As I'm not looking to conduct any aerobatic maneuvers, I'm thinking a 3/8" dowel might be sufficient reinforcement alongside the foam spar (an arrow shaft or similar length reinforcement probably won't be long enough to support a 2 meter wing).

 

[nerdnic]

The aluminum I use is 1/2" tall an 1/16" wide. I glue a layer of foam to each side of it.

 

[mrwis@yahoo.com]

Guys, thanks for the awesome suggestions. I'm likely going to build one straight wing for myself and reinforce it with the carbon tube I have and I'm going to head to lowes this weekend for a piece of aluminum to try that as well and for my friends planes. I'd like to make sure that all my friends have the same experience I do without any concerns.

Questions on that... Are you able to easily bend the aluminum if its mounted on edge as opposed to flat in the wing? Do you put it in and seal the wing up before you put the dihedral in, or do you bend it first and then try to glue it to the spar and fold the wing over and glue it at that point? Or... fold and glue the wing over, put the dihedral in and glue it, and then cut into the wing and insert the bended spar and glue up the seam?

 

[aeroncalover]

You could try fiber glassing the wing center section. I did that on a foam board DLG I made and while the glider never flew like I wanted, the wing never folded. I did put two hard wood spars in the wing, but neither of them carried through the center so the dihedral angle was not affected.