I’m having troubles with a 4+1 quadplane, Adele X10. If I transition to FBWB it seems to pitch up as the pusher motor spins up and climbs. I can see the servo outputs trying to fight this, but there is not enough airspeed for it to be effective. The first time I tried, it tumbled and I recovered in QHOVER. I moved the CG forward and tried again. It didn’t tumble this time but was oscillating.
Any ideas on where to look? Should I push the CG further forward? Would a slower acceleration help?
I’m looking at 5:22 - 5:36 in log 1
Log 1 - Moved CG forward
Log 0 - Tail Heavy?
Are you 100% sure your V tail surfaces are not reversed?
On one of the logs the pusher throttle comes in fast. I was wondering if it can cause a venturi type affect under the tail and cause a pitch up but your other log it looks more gentle. And recheck the CG.
That was my first thought, and I triple checked. I’ll check again because it is the most obvious explanation.
I’ll push the CG very forward and see how that changes things.
Is there a good pair of modes where I can get the throttle stick to zero for the transition and slowly ramp it up? I tend to go from QHover or QLoiter which need midstick to hover.
Im not up to speed on 4+1 vtol. Mine is tilting tri.
There is a lot of info here about thrust behavior during transition.
Ok, apparently this is “normal” for this airframe. Not sure I’m comfortable with this. I’m open to ideas to improve this. You can see it at about 43 seconds.
The only thing that comes to my minds is setting throttle slew rate.
As I said earlier, I suspect there may be a venturi effect from the propwash under the V tail. Like Lupus says, try to ramp up the throttle slower.
