Increasing versa lifespan

[Patrick]

Peace and love to all...

Need some help here please.

I've been trying to brainstorm a method of strengthening my enlarged versa wing I use for fpv, and any other contraption I build out of our favorite dtfb. I really like the versa for fpv, problem is, I fly fpv in weird locations without the plushest landing sites. I should probably rethink that, but these sites are so much fun. The landings usually require spot on accuracy if I want to touchdown on the soft bits, that is if they are even present, and I don't *always* nail it, you know. On occasion, this wing finds itself skipping merrily across craggy terrain or firmly ensconced in a thicket, chundered thusly, my wing generally has a short lifespan. Things start to get more and more floppy and the thing flies all wonky and what not. Since I have pretty much dialed most of my needs and mounting methods, I would like one to last a while. Any ideas? I tried bouncing ideas off myself, and it didn't work. I ended up in an argument with myself and said some things I can't take back. It got personal.

Anyways, the thing I have heard that sounds promising is filling the cavities with expanding construction foam. Then I suppose you could glue in some carbon spars and hack in recesses for electronics. Has anyone tried that? I'm curious about that, and unless I hear some glaring warning, I may have to give it a shot.

Another thought is it might be time to explore other building options. Maybe Sripol will inspire some depron action?

There's hot wire foam cutting too, but that's a whole big setup I'm not sure I want. It's just hard to give up five dollar airplanes from foam board, know what I'm saying? However, six airplanes later, cost is creeping up there.

Input appreciated! Curious if anyone has tried the expanding foam thing.

 

[Craftydan]

I've used expanding foam (the great stuff) on bloody wonders before, but not a versa. was very pleased with it. It'll likely drive a bunch of tail weight on the versa, and I'd find a way of boxing off cavities to prevent the foam from filling your electronics bays (servos especially), but it really firmed up the bloody wonder -- should do the same for the versa. When applying I'd recommend a sunny spot where you can see the light shine through the foam into the cavity, to know when you've got enough in.

I'd also recommend you consider stripping the outer paper from a built versa and replacing with packing tape. if you give sufficient overlap, it'll be a far stronger surface than the paper with a slight favoring toward reducing tail weight.

Another thing to consider, as you fold the wing, insert a fiberglass rod from a cheap kite along the leading edge. this will give the leading edge a bit more bounce resiliency.

Finally, I'd recommend looking into adding a coroplast layer on the bottom center of the wing and along the bottoms of the winglets as a skid plate.

 

[Patrick]

I've used expanding foam (the great stuff) on bloody wonders before, but not a versa. was very pleased with it. It'll likely drive a bunch of tail weight on the versa, and I'd find a way of boxing off cavities to prevent the foam from filling your electronics bays (servos especially), but it really firmed up the bloody wonder -- should do the same for the versa. When applying I'd recommend a sunny spot where you can see the light shine through the foam into the cavity, to know when you've got enough in.

I'd also recommend you consider stripping the outer paper from a built versa and replacing with packing tape. if you give sufficient overlap, it'll be a far stronger surface than the paper with a slight favoring toward reducing tail weight.

Another thing to consider, as you fold the wing, insert a fiberglass rod from a cheap kite along the leading edge. this will give the leading edge a bit more bounce resiliency.

Finally, I'd recommend looking into adding a coroplast layer on the bottom center of the wing and along the bottoms of the winglets as a skid plate.

Muchas gracias.

I like the fiberglass rod idea. I think I will try the foam, at least in front of the spar.

About the packing tape, does removing the paper help something? I always put what hobbyking calls a
Mylar wing tape on all the surfaces. Very thin, maybe packing tape would be stronger. Is removing the paper just a weight thing?

Coroplast layer, I like it.

 

[xuzme720]

Removing the paper is both for weight and helps battle de-lamination if flying in damp or humid regions. The tape added back to replace the paper is also for waterproofing but adds more strength without too much extra in weight. If you have access to cheap coroplast, that might be a viable option to rebuild with, it's certainly stronger than foamboard and less likely to soften in repeated less than stellar landings. A skid layer is a nice alternative as well.

 

[Patrick]

Removing the paper is both for weight and helps battle de-lamination if flying in damp or humid regions. The tape added back to replace the paper is also for waterproofing but adds more strength without too much extra in weight. If you have access to cheap coroplast, that might be a viable option to rebuild with, it's certainly stronger than foamboard and less likely to soften in repeated less than stellar landings. A skid layer is a nice alternative as well.

Ah yes the de-lamination.

Peter's kraft paper and glue method seemed like a good idea as well. I wonder if that is stronger than tape? It seemed like it would be stiffer, like in lieu of a big dent, you'd end up with a deep chip, if that makes sense.

Expanding foam in front of the spar, kite rod on the leading edge, Coroplast skid and fins, and lastly, peel paper and add some sort of covering. Then hope I don't need to run two 4000mah 4s in front to balance it out!

 

[Patrick]

I went ahead and built another 125% versa. This time, I cut doors in the top, forward of the spar for the vtx and the rx on the other side. I then boxed in the compartments and ran the necessary wire bits to them. I sealed up the boxes really tight and then pumped triple expanding foam in front of the spar. I also put skewers in the leading edge as I folded the wing over. It's drying now, I'm curious to see what it feels like tomorrow. This should be fast, I'm running a 4s and it's going to be on the heavy side. I also used a very small camera so it should be aerodynamically speaking, a bit sleeker than the big board camera.


One other thing I learned that I would like to share: The best thing I could have ever done to prolong the life of my beloved versa builds had nothing to do with construction techniques. My original problem was landing the rig in hostile topography. The best thing I did to preserve my wing is this: I built a tricopter. Problem solved. I can fly that thing anywhere! You don't need much to land a multirotor! Why didn't I do this sooner?