Hello to all you X8'ers,

I'm opening this discussion to find all of the optimal flight parameters for an X8. The parameters I'm trying to pin down to make an X8 fly as optimally as possible are listed below in order of importance. The current parameters are listed below, though they have obviously not been optimized yet. This should help anybody with an X8 to get in the air ASAP.

1. CoG. Updated: 1-2 inches in front of the stock CG seems to prevent stalls from constantly happening.
2. PID settings. Most say that default PIDs are optimal.
3. Maximum/minimum pitch/roll angles to avoid stalls. Pitch: -20*, 15*. Roll: 35* maximum bank.
4. Wing and aileron reflex to reduce stalls. 3* reflex at the wingtip trailing edge is suggested by some.
5. Wing pitch calibration for level cruise flight. I usually place the hatch cover under the nose when booting the APM, for approximately a 5* upwards inclination.
6. Maximum AUW/TOW. Maximum is thought to be at 3-4kg (6-8lb) but there are reports of heavier ones.
7. Elevon throws. 2cm movement in either direction with dual rates on, less when they are off.
8. Maximum motor size and pitch offsets. Below 2000W is suggested by some. 1.8kW has been tested.
9. Camera placement. Around the rear spar bulkhead is optimal for vibration reduction.
10. Whether or not the camera bump on the bottom of the wing should be removed. Experts (Daemon) have removed it, but most people (including me) have left it intact for various reasons.

This thread has been started partly for my benefit (so I stop crashing) and for the benefit of anyone with an X8 who keeps crashing.

I have attached a .tlog and mission file from a flight today in which I crashed the X8 into a 120' tree due to a stall and spin. The stall was likely caused by the observation of what appeared to be a flyaway, and my failed intervention. If anybody can help me understand if this was actually a flyaway caused by a hardware or software failure, or was just the result of bad parameters, I would be infinitely grateful. I have also included a photograph of the damage incurred by the crash, as Ning issues are preventing me from inserting an image into the text.

Everybody on the X8 forum: Please post any and all of your crash stories, .tlogs from them, photos of the damage, and parameters that I have listed above so we can finally figure out this airframe.

Many thanks,

Paul