I have been running 100/100 mix on my race wing for ages and my god is it nice to have the throw for fast rolling or tight loops. Plus you actually arent asking more of the servo than it can deliver (At least with edgeTX) because the radio will cap the output at 2000 or 1000 microseconds anyways so all the radio will tell a servo to do is go full deflectionand that's it.
Hey I was on that Facebook thread talking about my use of the 100/100 mix and going back and forth with Darren about it. I love Derren, so helpful, but so glad you made this video!
Good question. Great excuse to go flying! Think part of the assumption is range of servo is 1000-2000 mS, with 1500 mS PWM pulse width being centre. Some servos can/do go beyond these limits. Some servo checkers show the mS value (digital readout). It may be possible to test this using INAV via flight controller to set/see ranges and control surface deflections. Some battery chargers include a display page that also shows PWM signal values on a graph if plug in servo lead. All possible ways to test real limits on the bench. Not sure if INAV limites range, or resolution, as some microcontroller PWM devices do limit to 8-bits resolution, or 255 discrete position outputs .. 255 positions corresponding to 0% to 100%. It will also depend on how control surface deflections are set relative to maximum servo movement. (which holes on control horns are used) Generally, I don't think will ever be an issue ... worse case is one of the two control surfaces may not fully deflect as much as the other.
With a programmable transmitter or flight controller the only real downside of a 100/100 mix is that the max roll rate changes depending on how much pitch is input, and vice versa. With a 50/50 mix the max rates of each are independent of the other. I would suggest that if you’re never saturating the servos then you have them set up mechanically for too much throw and could probably adjust the linkage to get less throw and more resolution.
If the plane is as long as it is wide I sometimes add elevator to 60 or 70 percent to get the extra throw. The Prime Jet from Hobby King comes to mind with it's little elevons. It rolled great but had little low speed elevator response. Moving the cg back helps this but it's a balancing act like anything else.
Interesting video Andrew....Oh, and that hideous windy day....?..We get those for weeks at a time during Winter. In fact we are still getting them now, although today has been flat calm....🤔🙄🙄🇬🇧
It looks like you could get more throw by adjusting the linkages to put each servo closer to the center of travel. As shown they are each considerably away from center.
I'm a bit confused on the purpose of going 100/100 - I thought the argument was that way you could go from 50 up to 100 when doing a tight roll or loop - i.e. get full deflection when using just one input rather than half - but andrew seems to be focusing on scenarios when you would be aggressively using both
It's a mechanical system. You can't "saturate" it. When the servo hits full travel, it's done. Adding more mix just makes it happen faster. This was proven years ago when computer mixing in the radio came out. Running 100/100 for years. No issues.
Interesting! 60/60 has been what I used forever on my race wings. I really found no difference in control though between that and 50/50. Never tried 100% though.
Back in the days when i started flying wings like the Hobbyking Discover instead of regular planes i didnt even know this and always used 100/100 or 80/80 and never had a real problem 😂 People need to try more to learn
"A digital mix? How fascinating..." [Ref: a silly 'Not The Nine O' Clock News' sketch about a not-so out-of-touch courtroom judge.] Ah, does anyone else remember when V-tail and elevon control mixes were mechanical/analogue? No? Just me, then? Aww, poo. Perhaps it's time I bought myself that Shackleton's High Seat Chair. Well, kids, this is how it used to be: the aileron servo was mounted in a sliding tray, which itself was connected by pushrod to the elevator servo. The result was simple mechanical mixing which worked reliably and didn't require anything special of your servos (which were huge and heavy and hideously expensive). Of course, a modern digital setup is lighter and infinitely more flexible, but the ol' analogue system got the job done.
Now post the video on the Inav Fixed Wing Group and let them start arguing 😂
I'll get the popcorn ready
Haha, I don't want to stir things up too much, I count them as friends. But some rules have to be tested and maybe qualified.
I have been running 100/100 mix on my race wing for ages and my god is it nice to have the throw for fast rolling or tight loops. Plus you actually arent asking more of the servo than it can deliver (At least with edgeTX) because the radio will cap the output at 2000 or 1000 microseconds anyways so all the radio will tell a servo to do is go full deflectionand that's it.
Hey I was on that Facebook thread talking about my use of the 100/100 mix and going back and forth with Darren about it. I love Derren, so helpful, but so glad you made this video!
Darren is one of the best INAV tutors. But I thought it was worth testing the conventional wisdom.
Good question. Great excuse to go flying!
Think part of the assumption is range of servo is 1000-2000 mS, with 1500 mS PWM pulse width being centre. Some servos can/do go beyond these limits. Some servo checkers show the mS value (digital readout). It may be possible to test this using INAV via flight controller to set/see ranges and control surface deflections. Some battery chargers include a display page that also shows PWM signal values on a graph if plug in servo lead. All possible ways to test real limits on the bench.
Not sure if INAV limites range, or resolution, as some microcontroller PWM devices do limit to 8-bits resolution, or 255 discrete position outputs .. 255 positions corresponding to 0% to 100%.
It will also depend on how control surface deflections are set relative to maximum servo movement. (which holes on control horns are used)
Generally, I don't think will ever be an issue ... worse case is one of the two control surfaces may not fully deflect as much as the other.
With a programmable transmitter or flight controller the only real downside of a 100/100 mix is that the max roll rate changes depending on how much pitch is input, and vice versa. With a 50/50 mix the max rates of each are independent of the other.
I would suggest that if you’re never saturating the servos then you have them set up mechanically for too much throw and could probably adjust the linkage to get less throw and more resolution.
I have always used 100/100 on all my delta slope gliders and have never experienced any problems or had a servo fail because of it.
If the plane is as long as it is wide I sometimes add elevator to 60 or 70 percent to get the extra throw. The Prime Jet from Hobby King comes to mind with it's little elevons. It rolled great but had little low speed elevator response. Moving the cg back helps this but it's a balancing act like anything else.
Interesting video Andrew....Oh, and that hideous windy day....?..We get those for weeks at a time during Winter. In fact we are still getting them now, although today has been flat calm....🤔🙄🙄🇬🇧
It looks like you could get more throw by adjusting the linkages to put each servo closer to the center of travel. As shown they are each considerably away from center.
Yes I was nose heavy and un-trimmed. Adjusted for the next test
I'm a bit confused on the purpose of going 100/100 - I thought the argument was that way you could go from 50 up to 100 when doing a tight roll or loop - i.e. get full deflection when using just one input rather than half - but andrew seems to be focusing on scenarios when you would be aggressively using both
It's a mechanical system. You can't "saturate" it. When the servo hits full travel, it's done. Adding more mix just makes it happen faster. This was proven years ago when computer mixing in the radio came out. Running 100/100 for years. No issues.
Fair enough. Should be saying the servo input signal is being clipped
Nice test Andrew, especially in that wind ;-)
Thanks, I'm putting together a Theer wing at the moment. Your's looked like it flew well.
@@AndrewNewton Excellent flying wing. I think you'll like it. Good luck on your Maiden.
Interesting! 60/60 has been what I used forever on my race wings. I really found no difference in control though between that and 50/50. Never tried 100% though.
Good test 🎉
Thanks for putting this to the test 👍
Interesting experiment. Makes sense to me.
Rodgathat Man and such is life
and what could possibly go wrong 😉🙃😎
Back in the days when i started flying wings like the Hobbyking Discover instead of regular planes i didnt even know this and always used 100/100 or 80/80 and never had a real problem 😂
People need to try more to learn
"A digital mix? How fascinating..." [Ref: a silly 'Not The Nine O' Clock News' sketch about a not-so out-of-touch courtroom judge.] Ah, does anyone else remember when V-tail and elevon control mixes were mechanical/analogue? No? Just me, then? Aww, poo.
Perhaps it's time I bought myself that Shackleton's High Seat Chair.
Well, kids, this is how it used to be: the aileron servo was mounted in a sliding tray, which itself was connected by pushrod to the elevator servo. The result was simple mechanical mixing which worked reliably and didn't require anything special of your servos (which were huge and heavy and hideously expensive).
Of course, a modern digital setup is lighter and infinitely more flexible, but the ol' analogue system got the job done.
Very interesting !!! This is what I need to learn .... V_tail and alivons etc etc my brain hurts !!! 😉🙃😎
Best to start with the conventional 50 50 mix until you know what you're doing.