ORIGINAL: David Gibbs
CofG 20mm back from the front of the wing tube (about 2/3rds of the way back through it). Motor and stab at 0 degrees incidence; wing at +0.25 degrees. Minor mix of down elevator to low throttle. No mixing for knife-edge. 2 degrees right thrust close but not quite enough -- so a touch of right rudder mixed to higher throttle (multi point mix used to get this right from about 1/2 throttle up)
Normal flight trim:
- Elevator: Up 11 deg; Down 13 deg (approx 14 and 16 mm respectively at fuz end)
- Aileron: Up 6 deg; Down 9 deg (approx 10 and 14 mm respectively at fuz end)
- Rudder: 30 deg (approx 55 mm)
Snap trim:
- Elevator: Up 16 deg; Down 18 deg (approx 19 and 22 mm respectively)
- Aileron: Up 9 deg; Down 13 deg (approx 13 and 18 mm respectievly)
- Rudder: 20 deg (approx 40 mm)
Less expo on down elevator than on up; quite a bit more aileron differential than in manual (30% on JR10X) to stop adverse rolling.
Trimming update -- had another 5 good flights and handed it to one of the trimming gurus for an opinion. I haven't measured it again since, but the changes were:
- For normal flight trim -- about 10% more aileron throw to tighten up response.
- For snaps -- about 5% less elevator, 5% more rudder, and 15-20% more aileron.
Experimented a bit with the CofG, and happy that the 2/3 way back through wing tube works well.
Still has about 1mm of downtrim on elevator, so I will now tidy up engine and wing incidence relative to stab -- probably by lowering the back or the stab a fraction.
David