There doesn't appear to be many Quadplane flyers yet, so its still difficult to learn from other's experiences. I hope the moderator creates a category for Quadplane soon.
I successfully flew my new Quadplane , and I'm very impressed with its functionality. Thank you Tridge for making this possible.
Here is a Landing: https://youtu.be/lERyfchTvqo
Here is a Takeoff: https://youtu.be/f81n0aXdvKc
(these don't match the logs below)
My Quadplane is a conversion of the 3DR Aero using 1250KV motors and 9x4.5 props on 4S batteries. I tried to keep the props small to minimize drag in forward flight. I'm hovering at about 65% throttle, so I will need to increase the prop size once I add my payload.
I noticed that it is quite difficult to control the heading in gusty wind with the weathervaning effect. At one point while in QHover, the plane almost turned around to face me and I struggled to get it heading back into the prevailing headwind. I reduced Q_WVANE_GAIN from .1 to .05 and that helped.
Question: Why does the rudder not operate in Q modes? Wouldn't it help to yaw the aircraft using the wind?
I learned that it is better not to fly backward like I would with a copter.
I used the new Transmitter Tuning method which was well thought out.
Question: I don't understand the Tuning Error messages I kept getting. Mission Planner would say "Tuning Error 3.00" over and over and wouldn't shut up until I disarmed the plane. What was it trying to tell me? I don't feel my tuning attempt was very successful as I just can't get feel for what it is supposed to fly like. She's a big lumbering giant with sloppy control, but then again there is a skywalker strapped to this quad!. I'd love any advice on my PIDs that anyone can offer.
As expected the extra 1kg of weight and quad parts caused a lot of drag in forward flight. It normally requires about 110W to cruise at 15m/s, and now it takes about 150W, so that's about a 25% penalty. I wasn't ever able to find someone to give me an estimate on the penalty before I built it, so there it is. Let me know if your experience differs.
I did some auto flight patterns using VTOL_TAKEOFF and VTOL_LAND. For the most part it did very well. I realize looking at the logs that I forgot to update the Yaw parameters on this plane and the Skywalker is notorious for its horrendous sideslip at high power settings. This is a creating a problem for the Quadplane because the quad motors are working too hard to take out the yaw rather than the rudder. You can see in my short .bin and .tlog that during takeoff the plane is in a 15 deg bank angle, while the rudder is only providing damping. I'll try to fix that tomorrow. The takeoff went very well. It is a bit disconcerting to see the plane weathervaning around as it climbs vertically, but it did what it was supposed to. The Landing descent was too slow considering I only have 2 minutes of VTOL battery, so I increased Q_WP_SPEED_DN to 250.
Question: Why does it take so long to start descending after it transitions? Is there a parameter that controls this? Does Q_TRANSITION_MS only affect the takeoff transition?
Thanks for any advice you can provide. I'm sure I'll have many more questions tomorrow.
Quadplane is really incredible!
Here are the .BIN and .TLOGs