So I have some vacations coming up and already have some quads and a hex I figured I needed a fixed wing to round out my aerial camera fleet. (for now) heh. So I took the plunge and picked myself up an X8 to fill up with electronics.
I'm running an ArduPilot Purple, with a Castle 75 esc waiting for Hobbyking to drop of my new Scorpion motor until then I have a 700W max 50Amp local hobby store motor to power the bird. I'm running 1.2 video feeding through MinimOSD with a Sony 720 line mini cam. I have a roll and tilt GoPro mount in the works that I'll post up some pics when I can get some play time on the router this weekend. Communication is done through a Futaba 10C 72Mhz and some 900Mhz XBees.
I've only made a few mods for now like adding a second motor mount plate that bolt through the foam to the outer plate.
I made some electronics trays and filled in the lower camera cut out with some foam and Gorilla glue.
I ended up bringing the control linkage up through the wing, leaving it on the bottom seemed like a bad idea for a belly lander. I have never flown a or built a fixed wing, but I said the same about the multirotors and DIYDrone's gear and community made it simple, awesome and enjoyable. Only crashes were ah-hem user error. So I'm hoping for the same luck with this bird. I do have tons of hours now on RealFlight sim just to make sure I feel comfortable with the controls. That being said any input from from you guys will be greatly appreciated. I'll update this blog as things progress and as I get the camera mount going. But for now heres some more eye candy. Be happy and safe all!
Comments
Start with the defaults, or if you want to be extra safe, drop the default P values by 25% and expect it to be a bit sluggish in self-leveling. If it's too high you'll notice diminishing over-corrections which will be noticeable as it will want to snap back to level flight. Make sure you keep your airspeed up in turns with this airframe, and your CG is never too far aft, or it will side slip into a death spiral.
Thank you for clarification but....I just asked to share again an old link already present here but now dead just to have a comparison and start my personal tuning.
Take also into account that, in this thread, many people shared their setttings (including PIDs) without scandalize anyone. We are old enough to understand that we could crash our frame BUT i think that is better to have a parameter set from a frame that fly well that nothing to start from...
cheers,
Marco.
You can't copy the PIDs from one airframe to the next and expect decent results. Especially on this airframe since the servo arms are various lengths (depending on which servos you choose to install), and connection points aren't consistent from build to build (since it's up to the builder to install these as they see fit), and the PIDs would vary based on which holes in the servo arms you connect the pushrods. These all affect the amount of input needed to move the control surfaces. This is where the tuning comes in. I found the default were sufficient for keeping the plane in the air, but were a bit too high as the plane made too quick of a response to correct for roll offset and pitch offset. If you get the P values too low it will not respond (self-level) as fast as you want. It REALLY helps to assign a value to a pot/knob and change it while flying to get the result you are looking for.
Hi Jonh,
I'm new on this forum but i'm interest to parameters you shared long time ago for a comparison with mine.
Can you share again because the link (obviously) is dead?
thank you!!!!
Marco.
Alright thanks RickI have flow with manual al FBWA but the PID values aren't still that good, im waiting for a good calm day to tune them :)
I certainly don't have any better numbers to give. We crashed our X8 into the SF Bay a long time ago, and haven't tried flying a new one since. But the Pixhawk seems to work well right out of the box. Make sure your manual override is working, and just try it.
Hey Guys! I come in a couple of years later, but I just bouhgt an X8 Skywalker and had my maiden flight! flies amazing!!!
Just fitted the pixhawk, but its too dark to go and fly now (bummer..) :(
Since you guys already have some experience I was wondering about a good set of PIDs, I have found the settings from page 2, but i thought that someone might have more updated PIDs since that was June 2012.. :s
thanks a lot in advanced!
happy flying :)
Hi, everybody.
i have the same problem with the PID´s parameters.. =(
i have the pixhawk shield
some one can send me the parameters or something for to fly please.
thanks
Arrato, The defaults worked in stabilize, but I found they needed to be turned down a bit to keep it smooth, but beware of using others PID settings. Chances are your servos, servo arms or control surface brackets are mounted in different locations than others, and or using different hole locations in the arms. These will all have an affect on how responsive your plane will be to servo input(yours and APMs). Follow the tuning guidelines and know that you can always flip it back into manual if things don't look right. If you have stabilize mode moving your ailerons in the right direction for pitch and roll then you should be ok in stabilize mode. Oh, and never hand-launch these beasts. I got 14 stitches from my graupner 13x6.5, once. High-start every time now with latex tubing bungee and paracord.
Also looking for good settings for X-8. Please share..
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