Scioly.org

Now I'm not in Wright Stuff, but I'd like to congratulate Huntington Middle School from West Virginia on their HUGE upset, for a team that finished 55th overall this year, to actually win an event at Nationals is amazing. Huntington has proved that just about anyone can succeed at Nationals, no matter what the school. They were sitting right behind my team at the awards and they were EXTREMELY shocked at winning. Amazing job Huntington!

Attached is the link to Huntington Middle Schools first place flight (thanks to Dave and Eileen Ziegler for the video)

https://youtu.be/3h8CiLv9iwE

wlsguy wrote:Attached is the link to Huntington Middle Schools first place flight (thanks to Dave and Eileen Ziegler for the video)

https://youtu.be/3h8CiLv9iwE

Wow, that's an amazing fight!

wlsguy wrote:Attached is the link to Huntington Middle Schools first place flight (thanks to Dave and Eileen Ziegler for the video)

https://youtu.be/3h8CiLv9iwE

I have seen this particular Wright Stuff design (viz. no rudder, no dihedral, but tiny wingtips on both main wing and stabilizer) do very well at competitions and I am wondering if anyone knows where the original design came from or why it seems to work better than a more traditional design (dihedral on main wing and rudder)?

Crtomir wrote:

wlsguy wrote:Attached is the link to Huntington Middle Schools first place flight (thanks to Dave and Eileen Ziegler for the video)

https://youtu.be/3h8CiLv9iwE

I have seen this particular Wright Stuff design (viz. no rudder, no dihedral, but tiny wingtips on both main wing and stabilizer) do very well at competitions and I am wondering if anyone knows where the original design came from or why it seems to work better than a more traditional design (dihedral on main wing and rudder)?

It is a very common design used in free flight. We would probably have to go back many, many decades to identify when it was first used.

bernard wrote:

Crtomir wrote:

wlsguy wrote:Attached is the link to Huntington Middle Schools first place flight (thanks to Dave and Eileen Ziegler for the video)

https://youtu.be/3h8CiLv9iwE

I have seen this particular Wright Stuff design (viz. no rudder, no dihedral, but tiny wingtips on both main wing and stabilizer) do very well at competitions and I am wondering if anyone knows where the original design came from or why it seems to work better than a more traditional design (dihedral on main wing and rudder)?

It is a very common design used in free flight. We would probably have to go back many, many decades to identify when it was first used.

I was fortunate to provide the plan and instructions (and a little mentoring) to the Huntington WV team this year. The plan was based on the "Leading Edge 10" originally designed by the late Cezar Banks for Peck Polymers. Obviously the size was adjusted for the rules this year. I looked back in the 2010 Scioly forum but none of the links work anymore.

As far as working better, I can't say it does. The flat wing with no dihedral would theoretically provide more lift than a wing with regular dihedral but I don't know. It is a little easier to build since you build a flat section and then add the winglets.

The theory behind vertical wing fences is that it reduces the wingtip vortex of a conventional wingtip, a huge source of drag.
As a practical matter, they have to be very precise to actually eliminate the vortex and not add drag from being misaligned and snowplowing through the air.
And, they act exactly like dihedral, they are just an extreme form. Theoretically the best shape for dihedral is a wing with a half ellipse form when viewed from front or rear. But the difference in drag/effectiveness isn't generally worth the construction difficulties.
Simplest dihedral is single break in middle of wing.
Next is two breaks, flat center and tips lifted. The tip fences are just an extreme form of this wing. I've personally verified this (by accident, not intentionally) by building a plane one year with the tip fences down. It consistently flipped over on launch (when it didn't crash) and flew 'up side down' with the tips up!
Next is three breaks, center and two outer. Two outer breaks are above center break, and tips above that.
And you can continue.

Jeff Anderson
Livonia, MI

jander14indoor wrote:The theory behind vertical wing fences is that it reduces the wingtip vortex of a conventional wingtip, a huge source of drag.
As a practical matter, they have to be very precise to actually eliminate the vortex and not add drag from being misaligned and snowplowing through the air.
Jeff Anderson
Livonia, MI

Thanks. That makes sense. But what should we pay attention to make the wing fences "precise"?