Servos installation and setup. This is the most critical part of the built IMHO. It will determined how well or bad the heli will fly. A poorly setup bird will be hard to trim later on. A comprehensive setup can be found at raptortechnique, i did some adjustments as mine was a titan with push-pulls.
The servos were first installed as per manual and the push-pull links setup to the recommended lengths but not snapped on yet so that adjustments can be made later on.
The goal here was to work from the swash up and make sure that at half stick, the swash plate is level, then the wash out arms are level, followed by mixing arms level and then lastly the blade grips at 0 pitch. Make sure radio is at half stick at the start of setup! I use the throttle curve to ensure it to be digitally half stick.
To level the swash , i used 2 pieces of balsa with equal height as a guide. Started with the elevator since the A-shaped elevator control arms are fixed. Level the swash with the balsa pieces.
Fix the servo horn slanted at an angle on to the servo. Adjust the length of push-pull linkage rods so that they can snap on to the ball links on the control horn. The important part here is make sure both the push-pull linkage rod are equal length else it will cause binding. Use sub-trim to finish off keeping the swash level.
Next do the aileron. Again level the swash, keep the aileron linkage rods equal and aileron push-pull rods equal length.
The ball link on linkage rod A has the thunder tiger wordings facing inside the swash, while that on B is facing out to ensure both are same length.
For the pitch, adjust the collective control arm such that the washout arms are level. Then adjust the length of the vertical connecting linkage rod so that it can be 90 degrees to the pitch push-pull subassembly. This is to get same amount of movement up and down pitch,prevent differentials. The push-pull subassembly will be slight slanted when setup properly and not perfectly horizontal.Next adjust the mixing arms' long linkage rods to make them level. Then the short linkage rods to get blade at 0 pitch.
For the rudder setup, the best position for tail centering is to adjust the rudder link so that you have 4.5mm between the pitch slider and the tail rotor casing. This is to get around 15 degree of tail pitch built in to counter main rotor torque. Then use a horn with a hole far enough such that the linkage rod can be as close to 90 degree as possible to the horn. Finish up by CAing the 3 rod guides to the tail boom. Set up the gyro as per normal.
For throttle, use the ATVs and adjust the linkage rods to ensure no binding at both ends before snapping on the links.