How to trim a Stryker

[clough42]

I'm just starting out with airplanes, and I've got a question about trim and CG. I have a few months experience setting up and flying CP helis, but no experience with planks.

I have a ParkZone F-27Q Stryker, and I'm trying to get it trimmed so it flies well. On the bench, I set it up with the elevons dead-level with the wing (neutral) with the elevator/aileron stick centered. I've got positive and negative throws measured to the millimeter as described in the manual for low rates. I've also got the battery positioned to get the center of gravity exactly where the manual specifies.

When the plane is in the air, though, the nose feels heavy. I feel like I'm constantly pulling back a little on the elevator to keep it in level flight. If I let go of the right stick, it pitches down and starts losing altitude. I've tried putting in about four clicks of up elevator trim, and it flies a little more level, but I'm concerned that dynamically trimming it like this will cause problems inverted and when approaching stall speed for landing.

I tried moving the battery toward the rear about half an inch, and it makes the nose less heavy, but the plane felt a little less stable in flight. I'm very inexperienced and there was some wind, so it could have been coincidence, but I'm afraid that moving the CG further back might result in an uncontrollable plane (or pieces of a plane).

Should I keep pulling the CG back until it flies level with the elevons neutral? Should I use trim? Should I just fly it nose-heavy?

[Bob O]

I've flown a stryker for a while, very fun and versatile plane.

Keep the CG neutral or slightly forward, and use trim for level flight at mid throttle. If the plane climbs or descends with an increase or decrease in throttle from the mid point, you would benefit greatly from a throttle>elevator mix.

Does your radio have programmable mixing?

Sent from my phone

[clough42]

Yes. I am using a dx6i, so I've got two mixes in addition to the built-in elevon mixing program. I've heard bad things about dx6i elevon mixing, but I'm able to get the throws I need, so I think it's working for me.

When you say to keep the CG neutral or forward, are you referring to the factory spec, or level flight? I'm assuming you mean that I should get it to balance per factory spec on the bench and then trim it with enough up elevator to fly level.

Does this mean that I'll have to push the elevator a bit to maintain level inverted flight?

Should I expect the nose to drop as the elevator loses authority at low speeds, or is that where the throttle-elevator mix comes in?

[Desolas]

Check these links out too, good trimming information...

http://www.flyrc.com/500505

http://www.geistware.com/rcmodeling/flight_trimming.htm

I love the old Stryker, one of my favorites.