wing
 

here is my question.....i want to install a wider wing on a smaller plane.....(scrap parts)....to make a plane from them. how will this effect the handling?.....the fuselage took a 7-5/16 wide wing.....i have one 12" same span. i have altered the fuse to accept the wing....im wondering if i will have enough tail moment now?

RE: wing
 

edmoor,

Did you line up the original leading edges, trailing edges, or neither? Your concern for tail moment is probably the biggest issue. If the bigger wing is farther back on the fuselage you could have a handful in pitch sensitivity. There might also be an issue with tail size ratio with the bigger wing. This will establish how sensitive the new arrangement is to CG location. If it were me, and it still looked about right, I would give it a go. Doesn't sound like you have too much invested in it anyway. Might be a fun flyer. Balance as required by the bigger wing.

I once took a clipped wing from a GP Trainer 60 and grafted it to a fuselage with the tail of a Nosen 40 sizes Citabria and had a blast with it.

Good luck!

Bedford

RE: wing
 

As mentioned above, if balanced properly and pitch control is manageble, you will probably have more lift at a given speed than before, so you should be able to fly slower without stalling, assuming the AOA is also not too high for the new wing.

RE: wing
 

edmoor,

You may find some guidance for re-design here:

http://users.mo-net.com/shirl/Design.html

There is a practical relation among wing surface, stab surface, dihedral and vertical fin surface.
Deviations from that relation may cause problems with roll control, like Dutch roll or spin instability.

If it is marginal now, you also may need to increase the tail area, or the control surfaces of the tail for the new wing.

Not to be scared; I recommend replacing the wing and test fly it; then, making small changes as needed.

Be aware the original CG will shift after replacing the wing; just use an on-line CG calculator.

Regards!

RE: wing
 

thanks all for your help. i just centered the new wing....didnt use the old te or the old le.....so it overhangs both ends equally. i was planning on adding larger tail feathers.....just to be safe anyway.....although im not planning on making the fuse any longer. im hoping the cg will fall in the 25% range of the wider wing.....or fairly close enough to ballast it out. im going ahead with this thing....see what happens....[X(] only powered with a new OS .25. length of the fuse tip to firewall is 38". the new wing is 12" chord total flat bottom with a 2" thick airfoil.

RE: wing
 

You don't have to hope or even cross your fingers, just measure the sucker with a yardstick and you can easily find out exactly where the CG should be. It takes the size of the tail into consideration and how far back it is or isn't.

You make 9 measurements. Most modelers can measure stuff pretty accurately. Then you type them into an online workpage and mouseclick. Scroll down the same page and read out the CG location. Oh yeah, you have to type in the number "5" before clicking. So, you look for the CG location and write it down, then change that "5" to the number "15" and mouseclick again. Look for that CG location and you've got a safe, reliable CG range for your exact airplane. It's the easiest method around. And it uses the same formulas the aeronautic industry uses. Only you don't have to do any math, it does it for you.

http://www.geistware.com/rcmodeling/cg_super_calc.htm

RE: wing
 

still came out to 25%......its what i use anyway on all planes first flight. nice tool though.....thx!!

RE: wing
 

One general rule is vertical stabilizer is relative to wingspan, and horizontal stabilizer is relative to wing chord.  So, if you make a wing wider, you will need a larger vertical stabilizer and rudder. If you make a wing longer (front to back, or chord) you will need a larger horizontal stabilizer and elevator.