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Flap Fitting

lr172

Well Known Member
I foolishly forgot to install the flaps for fitting when I did my initial wing fitting and cover panel fitting. I figured that I would do any flap trimming after final wing mounting at the airport. However, the fuselage will be painted by that time. I am assuming that I will be able to put some tape over the paint and have no problems with scratches. Is there anything I missing here? Any "gotcha's" that will prevent me from pulling this off? I can't visualize any, but I haven't done this on a 10 before.

Currently seeing sub-0 weather, so this won't be happening on my driveway again any time soon.

Larry
 
Don't make my mistake

See this fancy drag-reducing closeout of the outboard end rib on my right flap? I did them on the inboard side as well. Before trimming the flap to fit the fuse. Without realizing the inboard end isn't exposed to the slipstream when the flaps are up.

It's all getting ground away to make room for flap fitment to fuselage. :(
 
See this fancy drag-reducing closeout of the outboard end rib on my right flap? I did them on the inboard side as well. Before trimming the flap to fit the fuse. Without realizing the inboard end isn't exposed to the slipstream when the flaps are up.

It's all getting ground away to make room for flap fitment to fuselage. :(

Looks pretty. Too bad it had to go. Your post earlier got me thinking about my error.

Larry
 
After 2 nights in the shop, sanding the inboard flap ends

and still not done - I'd say you have some work still ahead. (I'm also wondering how you rigged aileron and wingtip neutral without a full-up flap to work from, but that's another story.)

Plans call for 1/16" minimum gap between flap and fuselage. Now that I have flaps snuggly fitted, I will scribe a 1/16" line and remove flaps for final grinding / filing to that clearance (better access than lying under the belly). To get to that first fully-seated point without scratching your fuselage paint is going to require the greatest of care, I think. Work slowly, or you will scuff something.
 
I was wondering the same ting about the aileron/wingtip rigging without the flaps...

I did all rigging on the wing stand, before my wing attach work. Flaps were installed and forced all the way up against the spar; Gravity holds them there. Use a clamp to hold aileron in alignment with flap. Then adjust linkage to get the bell crank and torque tubes at their neutral positions. Then drill wingtips while held in alignment with aileron. Rigging to the control sticks and flap linkage rigging will be done at the airport, when wings are final installed. However, all parts get painted while still in my garage.

I couldn't afford to leave my plane on the driveway for several days with the wings on and my plan calls for paint before moving to the airport. Only had enough time for the basics of rear spar drilling and working with the wing root covers. I agree it would have been wise to put the flaps on and deal with trimming and flap linkage while at that phase, but I simply forgot to do it. This 6 was easier, as I could have one wing on while still in the garage and that gave me more time.

Larry
 
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Puzzled...

Final trimming of the flaps - - full-up against the rear spar leaves the trailing edge about 3/16" high vs the side/belly corner of the fuselage. With the care that Van's has put into the fit of the RV-10 components, I find myself second-guessing whether the flap reflex position isn't supposed to be with the underside of the flap perfectly aligned with the belly of the aircraft.

But I guess that's my OCD assuming that Van has OCD, too.
 
Fasteagle, your inbox is full

Hey, Frank -

My method was to fill the recesses with high density expanding foam from a spray can - Loctite brand from the local hardware. Let it expand for 2 days in a warm shop, then trim and sand flush, fill surface voids with micro slurry (epoxy/microballoons) and then wrap with lightweight crowsfoot cloth/epoxy resin, sand and fill as required. Best way to make the glass hug the outside corner geometry was to leave plastic food wrap over the glass ply while it set - this can be held down tightly with masking tape and comes off easily later.

Lots of work for what you get. There are other methods out there - balsa wood, phenolic plugs covered with glass, etc. Search around. Good luck!

And yes, I did all the control surfaces and tips this way.
 
I?m just curious about why. It seems like any drag reduction for finishing off the flap, aileron, etc ends would end up maybe increasing drag. The only air blowing through those gaps during straight and level cruise, would be the air that is leaking from the high pressure area below the wing/control surface, to the low pressure area above (or below in the case of the HS/elevator counter weight area). Wouldn?t you want to limit that leakage by leaving the ends open thereby increasing drag in that small area? I?m probably wrong about this, but it seems like you would be dumping generated lift and thereby increasing drag by requiring a corresponding increase in AOA and induced drag to make up for this lift leakage. Granted, the difference would be minuscule, but so would any perceived aerodynamic drag reduction from finishing an open rib end (absent any loss of lift). Maybe I don?t understand the aerodynamic airflow at the trailing edge of a wing, but I?m curious if you?ll see a difference using this technique, and what that will be.

It looks nice though, and if that?s the goal, I think you did a nice job of it.
 
Not worth it for mere cosmetics, IMO.

In my mind (and only there, perhaps) this was an exercise in turbulence reduction and therefore drag reduction. There's going to be flow from bottom to top of the control surfaces anyway. Might as well let the flow cross a mating pair of smooth surfaces versus crossing the mouths of shallow buckets facing each other.
 
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