wkevinm

Hi

I am making a quickee from scratch and would like opinions on the following moments:

Fuselage
Firewall to Wing LE 4"
Firewall to end of tail - 34 3/8"
Firewall to hingeline on V tail - 32 5/8"
widepoint of fuselage - 12 3/4"
High point of fuse / wing - 8 3/8"

Wing
Wing chord - 9.63"
Span = 52"
Airfoil - NACA 66-012

Engine - Nelson Q40, back plate mount

What is the CG range for a 66-012 airfoil, my guess is 3 1/2 (36%) to 4"(41%) from LE but an earlier post suggests 2.75 - 3"?

Any comments would help, I will be racing in the CPPRA (Canadian Prairie Pylon Racing Association) rules are slightly different than the AMA (wing thick, wide and high points).

Thanks for your support,
Kevin Moorehouse

diggs_74

With that airfoil I would say 3" would be the max I would go... Things get a little jumpy much past that. The firewall to leading edge might be a little long unless you are putting your servos behind the wing. I'm sure some guys with more experience than I have will chime in here shortly.

DMyer

My Feedback: (2)

I would shoot for 2 7/8" for the CG.... that will require about 3/16" up elevator for a proper turn. I would not go beyond 3 even though I have personally flown as much as 3.25 it is far too pitch sensitive. The Goldilocks spot is IMO is 2 7/8".


dan

Ed Smith

A word of caution here. A wing chord of 9.63 and a span of 52 gives a wing area of 500.76 sq". If you put a rad on your wing tips or even worse have an elliptical shape the wing will be undersize and illegal. I would suggest a chord of 9.75 min.

Ed S

diggs_74

Ed, I always thought the span measurement was a projected distance in a straight line not including dihedral... I didn't think wing tip shape was taken into account...Not trying to be a smart ***** just wondering... If this is the case I have had a couple wings with the 9.3" chord that was constant for 47.5" and wingtips that angled out from the LE to 2.25" at the TE...I guess was cheating..

splatt

I knew it , I just knew it....

garys

Lee, you are correct in how the span is measured, but incorrect about the tips not being taken into account...any Q500 wing with a 9.3" chord is illegal....[X(]
GS

js3

My Feedback: (3)

Kevin,

Make the wide point of the fuselage just before the trailing edge of the wing. This is a way to fake a wing fillet and as you probably know, fillets are against the rules.

Truckracer

My Feedback: (19)

Lee,

OK, the next time you beat me, my tape measure will be in hand!!

Roger S.

diggs_74

Don't worry too much Roger, Jesse, other NCPL racers... That wing and fuse are long gone... As a matter of fact, that wing lasted all of one lap.. However, it was the most spectacular mid-air I have ever seen and it was a pass for the lead around #2.. Took a Viper right in the middle of the wing right between the front wing bolts... A perfect hole the size of a spinner nut.... The only surviving part was the engine, the rest was junk.

The only reason I asked about the tips is that I didn't see it mentioned in the rules with regards to the wing area(I'm not implying it isn't there just that I didn't see it) .. If the tip area is to be included then who does the trig to figure out the area that is missing on a radius shaped tip??

HighPlains

My Feedback: (1)

The math is simple for just a rounded or parabolic shape. Or we can just count squares and get close.

Ed Smith

There is no mention of wingtips in the rule. The rule states just the minimum projected wing area. It obviously means the whole wing.

Ed S

diggs_74

If it was that obvious I wouldn't have raced an illegal wing ... Oh well, I guess a guy learns something new every day.

HighPlains

My Feedback: (1)

Nobody really looks too hard..........unless you win.

splatt

Buy me a beer, I might forgive you, make that 2

diggs_74

Jesse, you going to be at the meeting on Friday?? If so, we'll see about those beers, if not you're out of luck until racing starts again

Ed Smith

I was not trying to be a smartass. But wing area is wing area, what else is there to say?.

Ed S

diggs_74

I know you weren't Ed.. I know now so at least when these guys come over with a tape measure in the pits I won't have to worry...