rsieminski

Depth of the fuse: min 3.5" at its deepest point, which must occur within the wing chord. ???

1.) If the wing sits on top of the fuse, does this include the thickness of the wing in this depth measurement??

2.) I didn't see any limits on fuse lengths? Whats the optimum length?

Thanks,
--Rick

Ed Smith

The 3.5 fuse depth includes the wing thickness.

There is no rule governing fuselage length. You will probably get as many "optimun lengths" as there are people building them.

Ed S

PylonWorld

Ed,

Actually there is a limit.

7.1. Conventional design. Aircraft used in RC Pylon events shall be of conventional design with forward wing, aft horizontal stabilizer, and a single engine mounted in front. No deltas or other tailless designs shall be allowed. An aircraft shall be considered tailless if the ratio of its wingspan to its overall length is greater than 2:1. The "overall length" of the aircraft, for purposes of this measurement, is the distance from the front of the propeller to the trailing edge of the rearmost movable tail surface.


Rick,

I've compiled a database of most of the current Q-500's ... it's not quite in publishable form, but I can give you the typical ranges and most popular measurements.

Firewall to wing leading edge
Range: 4" - 4.5"
Common: 4.375"

Wing chord
Range: 9.65" - 10"
Common: 9.75"

Wing TE to stab LE
Range: 13.5" - 14.5"
Common: 14.125"

V-tail stab area
Range: 58 sq in - 76 sq in
Common: 67 sq in.

Hope that helps.

rsieminski

So the total fuse length cannot be shorter than 25 to 26". But all other things being the same, aerodynamically speaking, which would be less drag, hold more energy in the turns, faster? I would think a shorter moment would burn speed off more than a longer moment. I believe the predator has a 38" fuse. That's what most are flying at our club event, but I think I can build one better.

rsieminski

Eeeehh! I thought of another question: Why are the most common airfoils semi-symmetrical. eg. MH18B? Wouldn't a fully symmetrical wing be less drag?

PylonWorld

The MH-18B is a fast airfoil that also has good low speed and stall characteristics. It is a forgiving airfoil that doesn't react badly to tight turns, jerky input, etc.

The most popular airfoil in Quickie land at the moment is the NACA 66 series. The NACA 66-012 is fully symmetrical and is fast. However it is not a forgiving airfoil and washout is often used to tame it a little. You have to fly smooth turns with this airfoil. There are some dual servo tricks to making this airfoil more forgiving, but I haven't seen anyone using dual servos.

The 66-112 is also popular because it has some coefficient of lift (camber). It is a little more forgiving, and even though it is not symmetrical, the trade-off seems to work well.

DMyer

My Feedback: (2)

Currently the 66-012 symetrical airfoil with trailing edge reflex is the current rage in composite airplanes... some of us are also building them in balsa/foam(me for one).... it works very... very well. For fuselage length... don't worry about overall length as some of it is only to keep the V-Tail linkage buried. The moments are what is important... firewall to LE & LE to stab hinge line. Good luck.


Dan

MaxQ

I will be flying a couple of APRA planes this season which have dual aileron servos and very small control surfaces at the wingtips. Something to play with in my spare time.

MaxQ