Flying Le Fish: Basic TuningEdit
This is a discussion about how to set up your Le Fish to do basic aerobatic, not Mad Stab, flying.
Le Fish is designed to fly crazy aerobatics (AKA Ultrabatics), so don't be bashful with the throws.
- Set Elevator so you can just do stall maneuvers, such as snap rolls and spins, at full throw. This should be 15°-20° up and down with a full flying stab. You can use a bit of EXPO to soften the centers... if you like it.
- Set Ailerons so you have 35° to 45° of deflection up and down.
- Set Rudder to maximum throw... at least 45°.
Set the CGEdit
The goal here is to have a glider that flies horizontal, vertical and 45° lines (upright and inverted) with minimal to no inputs from the pilot. A good place to start, is to balance Le Fish at 3" (75 mm) from the leading edge, measured at the root of the wing. You will probably push the CG back a bit after you...
Do a "Dive Test". Edit
Launch and then trim your glider for level flight (hands off). Gain some altitude and then push into a 45° dive; center your elevator stick; and then see what happens. If your glider holds that 45° line, you have a neutral CG... the "holy grail" for discriminating Ultrabats. If the glider gently pulls out of the dive you have a slightly forward CG... the preference for many pilots. If she pulls up quickly (ballooning) then she is too nose heavy. If the glider steepens the dive (tucks) then she is tail heavy. Tail heavy gliders feel unstable in flight; but if the condition is not too extreme and the pilot is up to it, can offer opportunities for wild aerobatics... especially stall maneuvers.
If the CG is not to your liking... land; add/remove some tail weight (or remove/add nose weight) as needed; launch. Re-trim and do another dive test. Repeat until you are a happy camper.
Fly Inverted Edit
If you have to hold/push a lot of elevator to fly level you are nose heavy. If she climbs at low speed (and tucks at higher speed) she is tail heavy. Land; adjust CG; launch and try it again. Keep flying and adjusting until you can fly inverted with little to no push.
Always remember that when you push the CG back, you elevator will become more sensitive. You may want to reduce the elevator throw a bit, or add a bit more EXPO to compensate.
The number one mix you can use to maximize the aerobatic abilities of Le Fish is "snap flaps". The mix works like this: when you pull/push elevator, the ailerons move together (flapperons) to camber/reflex the wing a small amount. This is a standard mix for most decent transmitters. Set the mix so you camber AND reflex the wing about 5° to 10° at full elevator. You can put this mix on a switch... although most pilots just leave it on all the time.
Now go out and fly! Feel free to experiment with your CG, throws and Snap Flap settings. You may find that you have to adjust things from time to time... like your CG after a crash... or throws in very light or stronger lift conditions