Wing Tips...or NO Wing Tips?
 

Hi,

I'm planning on designing & building my own .40 size 3D plane (stealing heavily from other designs), and was wondering if I could get some advice on something?

I notice on many ARF planes (Laser 3D, Flip 3D, etc.) people saying that they fly better if the wing tips are removed. Is this true? Would it be best to just have my wings end at the last rib, rather that adding some kind of built up wing tip, to make it look better?

Any other advice you would like to share on ideas to incorporate into my design, to improve the flight characteristics, would be greatly appreciated. I know weight seems to be the main thing to watch out for in any 3D design.

Thanks,

Mark :p

Wing Tips...or NO Wing Tips?
 

I just finished my first scratch built which I designed like you described. As you said, keeping the weight as low as possible is the most important factor. Mine weighed 4lb 5oz with a 53" span. I used the Laser 3D plans as my starting point but made many changes.

I don't think having wingtips makes a whole lot of difference. The problem with the Laser design was the ailerons didn't go all the way out; they stopped at the wing tip. That's why people were cutting the tips off. I put tips on, but also included full span ailerons. It looks good and they are also very effective.

I would encourage you to get a pile of 1/16" balsa, cut out a rib template, and start building!

Tom

Thanks for your reply Tom!
 

I wasn't sure if the tips ware creating some kind of disturbance in the airflow, or some other problem. But after reading your reply, I did a quick check of the planes that I've heard off people cutting the tips off...sure enough! They all had ailerons that ended short of the end of the wing (because of the tips). If thats the case, I still think I'm going to add wing tips (I think they make it look allot better). I'll just make sure to make the ailerons extend all the way out, like you said!

Did you make all your moments, and surface areas roughly the same as the Laser 3D, or did you change anything to improve the way it flys? The reason I ask is because I was thinking of using the Laser 3D as a starting point, too, and modify some things to make it look a little better (to me anyway...I don't really care to much for the way it looks).

Thanks again for the help!

Mark

Wing Tips...or NO Wing Tips?
 

I kept the surfaces basically the same except the horizontal stabilizer is a couple inches narrower. The fuselage has more side area like the U-Can-Do and is all balsa. The cowl and canopy have been incorporated into the fuselage also.

I made the wing as one piece to eliminate the center joint. It is all /16" material with 3/8 sq spars. My ailerons are not quite as wide as shown on the plans but they are plenty effective!

This plane flys real slow and can loop in about 6 feet. There are a couple pictures in my gallery.

Tom