Stabilser Dimension Query

[Wellington]

I'm in the process of building a variant of the Slow Stick, and have a question of the dimension of the stabilser/elevator.

My wing dimension is 60"X10" giving me 600" sq.

I have read that the Stabilser is aprox 20% of the wing area, therefore the stabiliser needs to be 120"sq

I also understand, the aspect ratio should be 3:1 so I'm looking at a dimension of 20"X6" (ish)

I also know the elevator needs to be 20% of the stabilser. 24"sq

Now, my question is, is that 20% part of the original 120"sq, or is it in addition to the 120" ?

Any answers gratefully received.

Paul

[Ollie]

The 120 " Sq. area equals stab. (100 " Sq.) plus elevator (20 " Sq.).

[Wellington]

OK,

I see you're saying that the stabilser area includes the elevator,

so,

The total elevator area is 120"sq

The 20% for the elevator is 24"sq

Therefore the "fixed" part of the stabilser is 96"sq (120-24)

[vintage1]

The stabiliser area does indeed include the elevator, but there is no fixed formula for its size in relation to wing area.

It can range from zero, to 100%. A flying wing is, if you think about it, either a wing withouit a stablisier, or a stabiliser without a wing :D

What is crucial is the realtionship between the wing area, stabiliser area and the distance between them, and the position of the center of gravity.

A crude formula like 'stabiliser 20% of wing area' takes NO account of the cruciality of these other issues and their relationship.

[Wellington]

I knew this thread would start drifting off post sooner or later :rolleyes: (only joking)

I'm looking at a distance of about 2 X the cord, from the wing to elevator

Your choice of the flying wing is, of course quite true. I'm not sure if I'd ever have the confidence to try and fly one of those things, it just doesn't look natural :)

[vintage1]

Pop over into the scale forum where I stated a thread on CG location. The complete answer you want is in there. In laborious and very excellent detail

http://www.rcgroups.com/forums/showthread.php?t=339401

Essentially it matters not how big the stabiliser is.What matters is where the CG is and the depends hugely on the stab size and postion.

[Wellington]

Thanks for the link. Lots of reaing to do there. I've downloaded the scanned pictures from the article.

A bit of reading to do.

I have to say, this wil help me in my overall design. Good job it's not to late to change a few dimensions eh ?

Having read that, I have come across this link, which is very good (Mainly because I didn't understand some of the other terminology :-

C of G Calculator (and much more) (http://www.geistware.com/rcmodeling/cg_super_calc.htm)

Thanks again

[vintage1]

Fantastic bit of coding there.

I take my hat off.

I will be using that in due course :)