• This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.

question about flight controllers

#1
Hey all!

I am fairly new to the hobby, having started around June last year. I've built a Simple Cub, a Tiny Trainer, and a Tiny Arrow. I'm having a blast. I'd like to start getting into FPV, and I'm interested in getting DJI-like features on a fixed-wing build. I know the FT guys have talked about the Eagle Tree Vector system.

I was just watching some YouTube videos of guys building race quads and I was surprised at how cheap flight controllers appear to be. There appears to be a whole ecosystem of controllers based on ArduPilot that are a lot cheaper than the Eagle Tree system! I'm comfortable with soldering, so I don't see that as a deterrent.

I guess my question here is, has anyone here successfully put an ArduPilot system in a fixed wing bird? Can you point me to good articles or videos on this topic? Thanks so much!
 

evranch

Active member
#2
Ardupilot (Or rather, Arduplane, the fixed wing version if it) is quite easy to get going on a plane. It's almost plug and play with a Pixhawk type unit, with some fairly minor tuning. You can set the defaults, which should let you get into the air. Then you fly in AUTOTUNE mode and let it learn how your plane flies. Just visit the Arduplane wiki. Someday I plan to do a writeup but I'm too busy right now.

However, Pixhawk units are still pretty expensive. If you just want stabilization and don't need a whole ton of features, you can go with a Betaflight/iNav system on a quad flight controller board. They are also capable of loiter and RTL, I think.

If you want the cheapest, simplest "flight controller" then a LemonRX stabilizer PLUS is a set of gyros with rate and bank limiting as well as auto-leveling capabilities for $30.
 

ElectriSean

Eternal Student
Mentor
#6
This question might sound stupid to some of you, but what are flight controllers used for?
In a multirotor, they essentially convert the RC commands to motor outputs as well as auto leveling and autonomous features depending on the firmware. For fixed wing they are usually used for stabilization and autonomous functions.
 

CarolineTyler

Well-known member
#7
A flight controller is a microcomputer with a variety of sensors. It takes the radio control input from your transmitter and sends those commands to the motor (s) servos of your aircraft.
On a quadcopter it adds stability where they aerodynamically have none.
They can on planes, counteract the effects of gusts of wind which may push it off course.
Additional sensors for GPS, airspeed, obstacles etc. can give the aircraft 'intelligent' modes like hold position, return to home.
 

evranch

Active member
#8
This question might sound stupid to some of you, but what are flight controllers used for?
The stupid answer is "whatever you want to use them for!" I use mine primarily for waypoint-based flying for aerial mapping. It can fly a precise grid and trigger the camera at appropriate points, which would be nearly impossible manually. However, there are many more uses as the term "flight controller" is incredibly broad.

- SAFE could be considered a flight controller used for training purposes
- many 3D pilots use flight controllers with attitude hold functions to make impossible maneuvers easier
- flight controllers can stabilize gusty wind and allow you to fly in otherwise dangerous conditions
- FPV pilots use them for avionics display and the ability to return home if lost

among certainly many other uses.
 

mayan

Well-known member
#9
Thank you all for your answers! I think I have a flight controller laying around somewhere, how can you use it to help stabalize they plane and would you recommend to use this option to train ppl?
 
#10
What make of controller is it? They are all different in how you configure them.

I don't recommend using an FC in anything other than a basic stabilization mode as a trainer, as they can result in developing some very bad habits.
 
#12
Hello again everyone. I decided to grab a Matek F411-WING and associated goodies (a GPS reciever, pitot, etc). I'm going to be putting this stuff in my FT Spear.

I just realized I may need one more thing: A receiver that can output to sbus instead of directly to servos! I have a spare Spektrum AR610. I also have an AR620. It doesn't look like these things can talk to my FC. I see there are some converters that can take PWM and output to sbus but I'm a little nervous about pulling the trigger.

I'm using a DX6E transmitter.

Would y'all advise using the AR610 with a converter? I'll link the one I'm looking at. Or, should I get a receiver that can go directly to sbus? Thanks again for the help.

https://hobbyking.com/en_us/signal-converter-module-sbus-ppm-pwm-s2pw.html
 

ElectriSean

Eternal Student
Mentor
#13
Hello again everyone. I decided to grab a Matek F411-WING and associated goodies (a GPS reciever, pitot, etc). I'm going to be putting this stuff in my FT Spear.

I just realized I may need one more thing: A receiver that can output to sbus instead of directly to servos! I have a spare Spektrum AR610. I also have an AR620. It doesn't look like these things can talk to my FC. I see there are some converters that can take PWM and output to sbus but I'm a little nervous about pulling the trigger.

I'm using a DX6E transmitter.

Would y'all advise using the AR610 with a converter? I'll link the one I'm looking at. Or, should I get a receiver that can go directly to sbus? Thanks again for the help.

https://hobbyking.com/en_us/signal-converter-module-sbus-ppm-pwm-s2pw.html

The converter would probably be the cheaper way to go, but you'll lose the main advantage of a serial connection - the lower latency.