jim2

My Feedback: (1)

I'm building a Gentle Lady and making it electric. My set up is a Zagi 400 speed motor, 3.5 to 1 gear box, 10x8 Graupner folding prop,3 2100mah Li-Poly. This set up proudeces 21 oz. static thrust at 8.5 amps. I'm also using 1 of RA Cores foam wings.
I'm ready to put the motor in and wanted to know about sugested down thrust and right thrust. One person I know sugested 3 degrees down and 1 or 2 degrees right thrust but was'nt sure. I am going to use Flaperons and shorten wing tips to 8" with tip raised 1" at tip end.Please give me suggestions on the angle I should use at center--if any at all. I'm trying to finish this by the time my son comes in from the USAF 8/14.Oh I have floan gliders before but it's been 10 years and some of this is new to me--I have a programable radio--my first--love it.
Thank You
Jim

Peter Khor

My Feedback: (4)

1) The suggested thrust angle looks fine; fwiw I've flown 2m sailplanes with NO thrust angle, only needs a little right stick correction while climbing out.

2) Instead of Ailerons (which might not work too well with GL's poly-wing, (not to mention out-board flaperon problems), a better approach would be in-board Flaps, or a spoiler across top center of the wing. (the latter imo would be better, making it a RES Rudder-Elevator-Spoiler sailplane design).

3) I wouldn't cut down on the wing or modify it in any way (other than the spoiler).

jim2

My Feedback: (1)

Thank you for clearing up some of that. I said I was going to use Flaperons, I mean with the radio I have they would be like inboard Flaps and Aerilons in one piece--mixing the servos. The wing I have is'nt the stock one---it is made by RA Cores and has a improved airfoil where you use less dyhedreal and a reduced size of wing tip--not shorter in over all length just the tips measure 8" from joint to tip. Sorry I did'nt make that clearer.
Jim

Matt Kirsch

My Feedback: (21)

If you take a look at full-scale airplanes, you'll see that the flaps are toward the fuselage, not on the ends of the wing. This is so when the wing stalls just before touchdown, the middle section of the wing stalls first. When the outer ends of the wing stall first, the plane becomes unstable.

Here's what I mean: Get yourself a broomstick. Laying on the table, where it's supported along its entire length, shows you how a wing in normal flight is supported along its entire length by lift.

Now, balance the broomstick on your finger at the middle (see figure 1). This simulates a wing with the outer portions of the wing stalled, unsupported by lift just like your broomstick is unsupported. IT's tough to keep it balanced, yes? Wants to roll off to one side or the other quite easily, yes?

Next, balance the broomstick on two fingers at the ends (figure 2). This simulates a wing with the middle portion of the wing in a stalled condition. Much more stable, yes?

jim2

My Feedback: (1)

Thank You: Where would you suggest I place the Flaperons on the trailing edge as far as in respect to the flat area from fusealage to wing tip joint---they are going to be 1.5" in wide and how long do you sugest I make them?
Thank You