I'm currently making a plane that resembles the Diablotin Super. It is the same size and shape, but I'm making it from foam. And so far the weight is on target . What I am wondering is what those wingtip extensions are for. Or what they do. I've seen them on a few funfly planes and now I want to know what their purpose is. Or are they just there to pretty up the plane so the wingtips don't end up being flat? If they do end up being something useful for flying around the way this plane is intended, then I just may need to make some to attach to me's plane.

Here's a pic with what I'm talking about.


Thanks for the help.
Josh

I have Diablotin Std -- same size but more sturdy than Super. I like the wingtips, they are part of the desingn -- this is not a Morris knife!

What they aerodynamically do, I do not really know. The plane performs well, stable elevators etc. included. I would build it with the tips. Why would you want to leave them off?

From what I remember from an aerodynamics post is that this style of wing tip doesnt do anything except induce drag. Horner tips or winglets will add lift but are fragile. End plates will add lift as well and arent as fragile but will dampen snaps etc. Im no expert and just regurgitating what ive picked up.

So are those horner tips in that pic.? If so then I've just finally been learned what the name for em is. THX. LOL

Tuomo,
I'm not intentionally leaving em off. I didn't buy the kit. I've built a plane close to the size of the SD from foam and it already has a 61" wingspan without these tips. But I may add em if they help flight.

Thanks,
Josh

No those are not Hoerner tips. Hoerner tips can be found on a full scale Cessna 150, 172 etc.

the tips are only for the look, the plane doesnīt have any problems with elevator and harriers, very satable without mixing (but you will have to mix a lot of spoilerons if you want the plane to stall nose high because of the very low wing loading, the plane just donīt want to fall of the sky). I suggest that you keep the wingtips but extend the ailerons to the tip to get faster roll rates I have aprox. 45 deg. and believe me it doesnīt roll fast but it keeps rolling at zero speed

Add more lateral area arround the CG too like moden pattern planes. I did that and it works

I fly a Madness. The knifedge was terrible. Coupled very bad. I cut the tips and now it KE great.

As said by Daniel, Diablotin flyes perfect. Minimal coulping in knife-edge.

If you want to leave the tips off because they are not funtional, the leave also the cowl, canopy, turledeck etc off. ;-)

Do you have the special double reflex airfoil???... I didnīt so I have used the E169

no?

Whoops. Sorry bout that. I was intending to respond but fell asleep when I remembered this question.

But no. I used the S8035 14% thick foil. It said, "for RC Aerobatic," so I thought this would be a good choice. LOL

Josh

BTW. What is the special double reflex airfoil?

double reflex refers to the biconcave the airfoil, making both surfaces of the wing to be concave too, this is said that improves slow flying, give some atention to the ribbs in the picture of the diablotin, the diabolic 3d has the same airfoil also.

ohhh. DAR. I guess if I woulda actually thought about it, it would have made sense. "Double reflex." LOL

Well next version perhaps I'll use one. This version is about complete. Which makes me very happy. I just hope it flies extremely well.

Josh