wing strength inquery

hello,

Today I had my first real flight at baylands park in sunnyvale. I crashed the plane but it still is able to fly. The wings seemed to me that if the plane is pulling up that the wings are almost folding under the presure. Now that the wings have hit the ground 20 or more times the tendancy to fold is even more so. It is a plane called Acipiter Badius by Shun Da. Before I flew the plane I taped the wings with packing tape to strengthen the wings against tear out. But as to the strength against load I have to ask someone to advise how to make the wings more rigid. The plane was able to perform a loop (accidentally) with the wings in its current state, but not a full out high speed loop with the plane in a dive and pulling back on the control. This loop that the plane made did not result in a crash, however the plane has been in a crash first by hitting a light pole, then a crash straight into the ground, some touching wings to ground with plane spinning in a cartwheel motion. One crash the plane was stuck in the ground like a lawn dart. All in all the plane is in working condition but I think if the wings were able to remain rigid during flying manuvers that I would be able to control it better. What are you people using on your planes to make the wings stronger/rigid under load. I am including a picture of the wings that have crumpled under the severest crashes, but can still fly and are in one piece.

formatting link
could really use some help on this I didn't see anyone at the park today flying so I am asking you people for help. greg in san mateo california

Reply to
woodworking-greg
Loading thread data ...

Ted shuffled out of his cave and grunted these great (and sometimes not so great) words of knowledge:

Get some carbon fiber strips and CA or epoxy them to the wing. I suggest 1 strip full length on each side and a short strip infront and in back of the long strip to reenforce the center section. Garenteed the wings will not fold. Total added weight (including the epoxy) - about 1/4 - 3/8 oz (if you really slop the epoxy on).

Reply to
Ted Campanelli

Ted, thanks for the reply so quick. I see on hobby lobby that they are selling these carbon fiber strips. Which of the strips should I get and which ones (the strips of what width) go where.

formatting link
Ted

Reply to
woodworking-greg

Reply to
woodworking-greg

You might also be able to fit a couple of balsa or spruce spars to the underside of the wing, depending on how it is constructed and how daring you feel.

It won't take much to make the wing stronger, and a little drag around the spar probably won't hurt performance in any noticeable fashion.

Marty

Reply to
Martin X. Moleski, SJ

Here is an amusing recollection of Accipiter trials:

formatting link

As for myself, I got one off ebay with crumpled wings for cheap. I have good results with a $15 Aerobird Extreme wing, just had to poke a couple sticks through the right spots in the fuselage for rubber bands and glue down a 1/2 inch spacer in front of the wing to get the cg right. Definately the most durable (and therefore most used) plane in my hangar.

The BEST wing I have tried so far is when I strapped the wing off my skeeter onto it. It climbed great (for an accipiter badius) and flew fast and turned on a dime. Skeeter wing is in drydock at the moment after being hi-started into a tree...

P.S. not wing related, but an 8 cell pack helps noticably, after the original pack craps out of course.

Reply to
Steve Banks

stronger/rigid

today

Reply to
woodworking-greg

thanks marty I could try a wooden solution. I have a table saw that I could cut some spruce, I could also try some popular, which seems to be a light wood, strong and tight grained.

Reply to
woodworking-greg

Ted shuffled out of his cave and grunted these great (and sometimes not so great) words of knowledge:

The 1mm x 4mm strip should be plenty strong enough, especially if you apply it using epoxy.

Reply to
Ted Campanelli

Poplar would probably work fine.

You won't need much to keep the wing straight.

Popsicle sticks strategically placed might do, too, if they're long enough to go from a good solid area out past the crinkles.

Marty

Reply to
Martin X. Moleski, SJ

Most materials are stronger in tension than in compression, and so most wing spars should have larger members on top than on the bottom, unless the airplane is used for serious aerobatics with lots of negative G's. If the top of the wing or spar isn't good and stiff it will either buckle or crush, and no matter how strong the stuff on the bottom, the wing will fail anyway. You can't get that kind of top strength with tape. Properly supported wood strips work better.

Dan

Reply to
Dan_Thomas_nospam

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.