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spark
12-15-2005, 12:25 AM
When building a flat plate foamy like the Hobby Lobby Yuk 55, does anyone round off the leading edges of the foam on the wings, stab, or fin?

I've always rounded them just cause it seems like a smoother air flow is a better air flow. Just wondered if anyone else did the same or if I'm just wasting my time by doing it.

qban_flyer
12-15-2005, 03:51 AM
When building a flat plate foamy like the Hobby Lobby Yuk 55, does anyone round off the leading edges of the foam on the wings, stab, or fin?

I've always rounded them just cause it seems like a smoother air flow is a better air flow. Just wondered if anyone else did the same or if I'm just wasting my time by doing it.

Nope!

I don't think it makes any difference in its flight characteristics since its wing has no airfoil per se, the very reason they have no glide to peak of. The H/L YAK-55 is built the same as the rest of flat foamies available.

My E-Flite Ultimate FX 3D has a full fuselage, yet its wings are flat and have square edges as well. :)

Bill G
12-18-2005, 03:57 PM
On standard airfoils, the story I hear is that the sharper the LE curve, the more abrupt the stall. I'm sure there are a number of variables that play into this, however. For instance, bringing the apex point up a bit on the LE of a flat bottom airfoil is supposed to increase pitch stability.