Has anyone weighed a D&E stamped rib? I wish I would have weighed one of mine. They sure seemed light to me but had nothing to compare to. All this talk of extreme weight saving wasn't around when I was building mine. I just put it together and have a nice flying Super Cub.
That looks great gsmx440. You seem to have the procedure down. Can you get 6061-T3? That should work easier.
Place a full sized rib at the tip. This will give you an attachment for the squared off removable tip....I'm planning to run flap and aileron from the fuselage to the square tip of my wing. If I'm not missing something, the length will be 16' with the rear spar being the limiting factor. Because of weight and because of C90 engine, The wing I envision is a standard 13 rib with an aileron rib in place of the wing tip rib and a 14th aileron rib on the end of the rear spar.
You still will need to address the air load on the leading edge which is trying to collapse it. This is the main reason for the nose ribs.Not knowing much, but sounding like a good idea is making the leading edge from carbon fiber and doing away with all the nose ribs to save more weight.
I like drooping ailerons. I have flown them on a Cub. They do help take off and landing performance. The Cub, which I have flown, had them connected through a complicated movable pulley system to the flap handle (weight). Drooping aileron systems reduce the up aileron travel which is important in crosswinds. The question of up for higher cruise only works on certain airfoil shapes. I doubt that the Cub is one of those. I rigged the drooping ailerons on my 185 so that I could test this theory by varying their position while in flight. Any position other than neutral, slowed down the cruise speed.I also like the thought of adjustable droop ailerons. If I understand, one could dial them up for better cruise and dial them down for better slow flight.
Mine are squared and slightly drooped. Screwed on to the tip rib. They will have less drag if they are most any shape other than "just left off".I'm not sure on wing tips yet, but again I am pondering making my own from carbon fiber or possibly leaving them off entirely.
Mine is 88" with the control horn at the inboard hinge location.From what I can gather from the prints, it looks like a standard aileron is roughly 102.125 inches and a standard flap is roughly 62.5 inches. It also looks like the standard chord length for both flap and aileron is 13.25 inches. If I do what I plan, it looks like I'll have roughly 25.25" to fill in with either aileron,flap, or a combination of both.
Here are the burning questions...
How long for the aileron?
Mine is 110" starting at the fuselage.How long for the flap?
Mine is standard chord.Should I go with the standard chord for flap and aileron? I'd like to because of weight and simplicity but again, I don't know much.
792 pounds is a lofty goal. Good luck.Keep in mind C90 engine, primarily wheels/ski's with possibility of future floats. 792 pounds. Not a STOL competitor but want to hop off the ground and land/fly slowly with control. I am going to shy away from LE slats/slots in favor of a little more cruise speed. I want to build the toughest, lightest wing I can and not worry about tearing it off.
Thanks,
Jim
Were it me, I'd forego the 90 and run an O-200 with 9.5 pistons for an extra 10% power and torque. Combine with a Mac 7535 for takeoff and climb. Does great climbing at 55 mph and 2850 rpm.
..A guy who increased the gross weight of some early supercubs told me that he had quite the go around with the faa on increasing the gross of 13 rib cubs. He told me that the main reason piper added more ribs had to do with the VNE and the leading edge collapsing at really high airspeeds, and not with needing more ribs to take the weight. I would personally go with the 13 ribs as the ones you are building are much stronger than piper's.
the main reason piper added more ribs had to do with the VNE and the leading edge collapsing at really high airspeeds, and not with needing more ribs to take the weight. I would personally go with the 13 ribs as the ones you are building are much stronger than piper's.