Flap and Aileron Materials???

[EDMO 1078]

Looking for comments:  I have a choice to make when cooler weather comes back this fall for making separate flaps and ailerons: 

1.  I can make wood ribs with aluminum tube leading edge and aluminum trailing edge and cover with fabric for either or both the Flaps and Ailerons. (Sounds easiest)

2.  I can make wood partial ribs and use aluminum for rear portion of ribs and cover with aluminum skin using about 1000 blind rivets. 

3.  I can cover wood ribs with fiberglass and glue with 9460 or something.  (and I hate finishing fiberglass!)  

4.  I can cover wood ribs with 1mm plywood, like I did the leading edge of my wings.  (possibly better and as easy as fabric)

5.  I can do the Flaps one way and the Ailerons another way.  

All thoughts appreciated.   EDMO

Edited 13 Jun 2016 by EDMO

[TJay 1041]

My self I would make Aluminum ribs and cover them with aluminum and cherry rivets. I did that on my Sonex Tail, only took a few hours once I got my Block of wood made, 

[EDMO 1078]

My self I would make Aluminum ribs and cover them with aluminum and cherry rivets. I did that on my Sonex Tail, only took a few hours once I got my Block of wood made, 

TJay,  The only problem I have with that is that the ribs have to attach to the pivot tubes - I don't have an engineer to tell me how many and where to put what kind of rivets to attach the ribs to the pivot tubes.   I know how to Hysol wood to aluminum tubes with no cracking from holes/rivets.   EDMO

[lostman 198]

Ed, I'll see if I can get you a couple pictures of the wings from my Teenie Two. It is one piece of aluminum for the aileron. Only one rib on each end and attaches with two 6" pieces of piano hinge. Very simple and should be fairly quick to build. It is literally one piece that is put in a brake and bent to complete shape so it comes back and overlaps where the cherry max type rivets are popped in every inch. The Sonerai I'm building is the exact same thing. 

[EDMO 1078]

Ed, I'll see if I can get you a couple pictures of the wings from my Teenie Two. It is one piece of aluminum for the aileron. Only one rib on each end and attaches with two 6" pieces of piano hinge. Very simple and should be fairly quick to build. It is literally one piece that is put in a brake and bent to complete shape so it comes back and overlaps where the cherry max type rivets are popped in every inch. The Sonerai I'm building is the exact same thing. 

Kenneth,   I have to use a pivot tube at 1/4 chord like the flaperons for the controls to work, and the ribs transfer the movement pressure from the pivot tube to the 15" chord flaps and ailerons.  Thanks anyway,   EDMO

Edited 15 Jun 2016 by EDMO

[lostman 198]

Is there a reason you can't build them like the Avid/Kitfox have? Just a tube and aluminum wrapped around it and riveted on the trailing edge? They look simple enough. I don't see why you couldn't do a tube in a tube design that way either. 

Maybe I missed something here....

[EDMO 1078]

Is there a reason you can't build them like the Avid/Kitfox have? Just a tube and aluminum wrapped around it and riveted on the trailing edge? They look simple enough. I don't see why you couldn't do a tube in a tube design that way either. 

Maybe I missed something here....

I think the pressure on these will be a LOT greater than the flaperons - basicly, I am putting the same air pressure on a 6 foot, 15" wide aileron that is on 12 feet of 9" foam-filled glued flaperons, and the pressure on the 15" wide 6.5 foot flaps with about 30 to 40 degrees down should be greater than that?  I guess an engineer with a good calculator could figure out the differences, but just as my guesstimate, it should be about double the pressure at the trailing edge of the ailerons, and lots more on the flaps?  EdMO

Edited 15 Jun 2016 by EDMO

[TJay 1041]

Doug H should know what to do, that plane that he is building right now I believe uses aluminum ribs in the wings on a tube spar see how there attached and just scale it down a bit.

[EDMO 1078]

Doug H should know what to do, that plane that he is building right now I believe uses aluminum ribs in the wings on a tube spar see how there attached and just scale it down a bit.

I would be interested in seeing what Doug has.    EDMO

[dholly 718]

My wings are aluminum rib/nose rib on standard aluminum spar tube construction with a composite leading edge extension and covered with Polyfiber. The flaperons use full length control tubes and seamless composite skins. I've never had them apart but, no rivet heads showing so I don't know if the skins are bonded over one continuous airfoil shaped piece of foam or there are mini aluminum ribs with foam filler between. I'll try to take a closer look or dig up the info.

[EDMO 1078]

My wings are aluminum rib/nose rib on standard aluminum spar tube construction with a composite leading edge extension and covered with Polyfiber. The flaperons use full length control tubes and seamless composite skins. I've never had them apart but, no rivet heads showing so I don't know if the skins are bonded over one continuous airfoil shaped piece of foam or there are mini aluminum ribs with foam filler between. I'll try to take a closer look or dig up the info.

Doug,  The flaperon skins must have some sort of rib material bonded to the control tubes in order to prevent slippage.   Thanks,  EDMO

[TJay 1041]

I think if you were to pound out an Aluminum rib then drill a hole through it, About a 1/3 of the way back,Right where you want the aluminum tube to be, then lay a nice bead of Hysol around the tube onto the rib, I would think that would be plenty strong. Without any Rivets. Its really not that much different than gluing the Kitfox rib onto the rear spar. Look how much wing is hanging out behind the rear spar. I bet that glue joint takes a lot of pressure.

[TJay 1041]

I found a pic of what I am trying to say if it doesn't make sense. It looks like the Highlander uses this system. I was just saying use aluminum ribs but wood would work too. looks like they cover in fabric but you could wrap a sheet of aluminum from front to rear also and forget the fiberglass leading edge.

 

[EDMO 1078]

I found a pic of what I am trying to say if it doesn't make sense. It looks like the Highlander uses this system. I was just saying use aluminum ribs but wood would work too. looks like they cover in fabric but you could wrap a sheet of aluminum from front to rear also and forget the fiberglass leading edge.

 

TJay,  That is similar to what I was thinking, except I also have an aluminum tube as the leading edge like the Avid/Fox wings - I can go all the way with wood like this, or only go past the pivot/control tube with wood and use aluminum rib for the rear part of the ribs - Covering options are fabric, wood, or aluminum....That's the next decision.

Thanks,  EDMO

Edited 16 Jun 2016 by EDMO

[TJay 1041]

Similar to what my challenger had then, you bend the tabs around the tube and attach with 4 rivets, If I was to do that type system  again I would hysol them also. Here is a photo of a challenger Flap assembly.

 

[EDMO 1078]

I will be posting some construction photos this fall.   The one concern I have about using fabric cover is the slits for the hangers, but I think a 1mm plywood cover over the two ribs where the hanger is located would work good.  That is now my plans.  Thanks,  EDMO

Edited 22 Jul 2017 by EDMO