Big Bird with flaps?

[jbird]

I'm in the process of building a Big Bird. I've got the wings just about done and have been deciding how to add spoilers. I tried to go to the only field near where I live that I can use a hi start to fly my aquilla but too windy today (newbie and the flags at a nearby business were straight out with the trailing edge flipping rapidly). I did see that heavy equipment has been moved on to the site so am about to loose the field for flying.

I'll pull an axi out of my vermont belle and turn the BB into a motor glider (haven't started the fuse yet) so I can fly in smaller fields. I'm already leaning to servos in the wings for the spoilers but after reading several of the threads here, I'm thinking I should just go for flaps instead. I could then get camber adjustment in addition to landing benefits.

I'm not much of a builder (great at repairs though.... :rolleyes: ). I've done a couple of searches but nothing that helps me. Can anyone point me to a thread with pictures that might clue me in on the best way to make up the flaps?

Any help is much appreciated,

Jim

[StevenatorLTFO]

I have a Skybird (big brother to the Big Bird) that the original builder added flaps too. They start in one bay from the root, and end one bay before the poly joint. They travel up enough to get a little reflex, although it really doesn't speed up this airplane very much, and I get about 60 degrees of down throw, mainly because of the geometry of the linkages. Each is driven by a servo buried into the wing. The 60 degrees of throw does help greatly with the landings, and I use a little bit of flap on the launches, and when thermalling.

Ok, so, onto adding flaps into the wing itself. Its really not too hard, especially if you haven't built the wing yet. Essentially, what you will want to do, is draw out where you want the flaps to be on the wing plans. On my Skybird, they are 2 1/4" wide. Look at a rib profile, and decide how big you want yours. About 20 percent or so of the chord is a good place to start. ie: If your wing chord is 10 inches, your flap chord should be in the neighborhood of 2 inches.

Where your flap line is going to go, you will need to modify your ribs, removing the section where the new structure for the back of the wing, and front of the flaps will be put. The thickness of the structure, will determine how much of the rib to remove. The cut off rear portion of the rib, will be kept to build the flap with.\

I've made some rather crude drawings to give you a rough idea of what I am talking about here. They should give you an idea to get started. Take your time, and plan your work, and this mod will be easy for you.

Steve


Here is a thread with some pictures

http://www.rcgroups.com/forums/showthread.php?t=654956

[jbird]

Just got back in from going to a play at the local theater with my wife and friends. I'm looking forward to studying the info you sent me tomorrow (my peepers are getting heavy :D ).

Thanks much for your help.

Jim

[balsabozo]

I did this to my bigbird xl and documented it here on rcg.
good luck - i luv them, makes them land more like a td plane than a scale ship

http://www.rcgroups.com/forums/showthread.php?t=719147&highlight=big+bird+flap

http://www.rcgroups.com/forums/showthread.php?t=654956&highlight=big+bird+flap

[jbird]

thanks for the info. I'm going to get started on it this weekend.

Jim