7SS Flaperon Chord Length?

[FoxbuilderWill]

I'm rebuilding a model 1 and looking at the flaperons and considering building a new set. Mine are completely undamaged but I've heard some people express discontent about the roll rate on the early foxes, which is something I want to improve while I'm doing all this work.

I know that they went from flat bottomed on the 1-3 to symmetrical on the 4-6 And now on the 7 use a semi symmetrical airfoil, so I think I would go that route as well. As the title indicates I'd like to know the chord length of the current flaperon. I'm wondering if it got a little bigger in the current aircraft? My flaperons have an 8" chord length.

[Eric Page]

Not exactly what you asked, but my Series 5 flaperons are sitting a few feet away. Chord length is a hair under 10-1/4". Spar tubes are 0.875" OD x 0.039" wall.

[FoxbuilderWill]

Not exactly what you asked, but my Series 5 flaperons are sitting a few feet away. Chord length is a hair under 10-1/4". Spar tubes are 0.875" OD x 0.039" wall.

Good info thanks. One more question: what is the thickness of the airfoil at the thickest point? I'm guessing that's a little more than that .875" tube?

[Eric Page]

One more question: what is the thickness of the airfoil at the thickest point?

It's 1.45". The centerline of the spar tube is 2.4" aft of the leading edge, and the thickest part of the airfoil is about 1.2" aft of the spar centerline.

[FoxbuilderWill]

It's 1.45". The centerline of the spar tube is 2.4" aft of the leading edge, and the thickest part of the airfoil is about 1.2" aft of the spar centerline.

Thank you. It's interesting that despite having the same main wing area (42" chord x 13.5' semispan) the newer kitfoxes have 20% more control surface area. Definitely one of the reasons they have better roll rate.

The newer foxes also have a lot less dihedral.