This is a very long, very detailed explanation of how to get a plane through a successful autotune. I believe people still don’t understand the process all that well and what I am sharing is what I’ve learned from performing the process on many planes. Pay a lot of attention to the Autotrim process. It’s crucial. The steps cover can be found in Phase 1 MasterClass Tuning on our website. We’re going to cover how to undo your previous Autotune and Autotrims so that you can start over. Then, we’re going to check for errors in board alignment, give you some useful PID settings. We’re going to review your plane, how to place your electronics, Review Center of Gravity, and do a side-to side-balance. Then we’re going to go into the four steps
1. Manual Tune
2. Flying with Flight Modes
Questions? Feel free to write to me at here.
- Successful INAV Setup
- Identifying issues with planes flying with INAV
- A few things to check before we get started.
- #1 Backup your install
- #2 Snap photos of your control surfaces
- #3 Artificial Horizon
- #4. In the configurator, does the graphic on the first screen show the plane leaning left and right correctly?
- #5. Is your flight controller close to CG?
- #6. Add some pitch to your flight controller
- #7. Starting Fresh- DO NOT RESET YOUR FLIGHT CONTROLLER
- Looking at your PIDS
- #8 PID page, Rates & Expo tab
- #9 Roll rate and pitch rate.
- #10 Reset your Servos to 1500
- #11 Reset Control Surfaces to what you feel should work
- Overview of the process:
- The 90/10 Rule
- The plane
- The Build Process
- Center of Gravity
- Side to side balance
- Step #1. Getting a good manual tune
- Your first manual flight.
- How to evaluate a manual flight
- Planes that are nose Heavy
- Planes that are tail heavy
- What you can do about a tail heavy plane.
- Adjusting for roll and yaw
- The nuance of flying manual
- Before you move on
- #Step 2 Moving into modes
- Step #3 How to Perform an Autotrim
- Evaluating your Autotrim
- Back to the field
- Step #4 Perform an Autotune
- How often do you have to do an Autotune?
- How often should you do an autotrim?
- Still have issues?
- Want to keep going?
- Final Thoughts
Successful INAV Setup
If you’re reading this, there is either one of two things going on. Your plane does fly with INAV but it could fly better or you want to know how to get a successful INAV setup. We’re going to assume two things.
#1 Your plane is mechanically mostly setup correctly.
#2 Your flight controller is mostly setup correctly
We’re asked to troubleshoot issues with group member videos all the time. Mechanical issues are common, and nearly impossible for us to figure out. When a clevis is broken or a control rod binds but functionally works, sometimes, we can’t diagnose these issues. The assumption is that your plane is flight worthy. If it’s not, you really cannot perform a successful INAV setup.
We are going to assume you use a fresh profile in your radio for your build. No mixers, no trim tunes, no servo reverse. Change your servo directions in INAV configurator, not in your transmitter. Your plane may crash as soon as you enable an autonomous flight mode such as Return to Home if you fail to pay attention to this.
We’re going to assume that you have the flight controller calibrated, installed, working and has no glaring issues. If it’s not ready, check out our INAV Fixed-Wing Setup Guide. If you’re stuck and you cannot find the answers in the guides, be sure to hit up the group with your detailed question providing as much information about the problem as possible. Someone will help you.
Identifying issues with planes flying with INAV
If it doesn’t track well, if it feels like it may fall out of the sky, if it pitches up and down, or rolls side to side on non-windy days, you’ve got a problem. If you put the plane into manual and it becomes uncontrollable, you’ve got a very big problem. Or if you can fly well in manual but the flight stabilization modes and Return to Home becomes a flying nightmare you’ve got a problem. The solution is to reset your PIFFs and reset your servos to 1500 in INAV Configurator Outputs Tab and start over.
A few things to check before we get started.
#1 Backup your install
Go to CLI and type either “Dump” or “Diff” save that to file. This is the current state of your plane including the calibrations and all your settings. You want to do this every so often, especially if you’re about to make major changes to INAV. These are very, very small text files and take up very little space on your computer. Make a directory by plane and store the diff or dump files by date.
#2 Snap photos of your control surfaces
This is for planes that can be successfully flown, when you get to step 11 you may want to reposition the control surfaces to their current state. If your plane hasn’t flown yet, skip this step.
This handy tool may also help: https://www.thingiverse.com/thing:4204865
#3 Artificial Horizon
When you hold the plane level, does the artificial horizon show level in your OSD? If the answer is” no”, you will need to recalibrate your flight controller. You do not want to put your plane in a flight stabilized mode if you’re having this issue. What you think level is and what the plane thinks level is, are two different things.
#4. In the configurator, does the graphic on the first screen show the plane leaning left and right correctly?
If not, watch this brilliant video by Darren Lines about setting board orientation and pitch. https://www.youtube.com/watch?v=ox9f_KaugHA
#5. Is your flight controller close to CG?
It needs to be. The flight controller works under the assumption that it’s sitting close to CG. When its away from CG INAV won’t be able to work as well.
#6. Add some pitch to your flight controller
( not physically, in INAV configurator )– What you considered to be level will actually cause the plane to lose altitude. Darren Lines covers this topic in the video referenced in point
#7. Starting Fresh- DO NOT RESET YOUR FLIGHT CONTROLLER
That will put you back to factory defaults. You will need to go into the PID Tuning tab in INAV Configurator. Take screen shots of each tab. In case you want to go back you can reference these settings.
Looking at your PIDS
If any of the P or I settings are over 20, let me ask you a question. Did you skip the autotrim and go straight to an Autotune? If the answer is yes, then you’ll notice fairly high numbers in this section. What this is telling you is that the flight controller is working very hard to compensate for a plane that isn’t well trimmed. We’re going to fix this. Resetting the PIDs means we cancel your autotune and will start over. There is a reset on the first screen. Go ahead and reset. If this is a fresh build you don’t have to do this step, it’s at defaults to start with.
#8 PID page, Rates & Expo tab
You are going to use Angle Mode, and chances are, if you don’t change the MAX PITCH and MAX ROLL setting it will make turning your plane in Angle Mode very difficult My Go to settings are 60 for roll and 40 for pitch. Changing this will also impact how Horizon Mode works.
#9 Roll rate and pitch rate.
Roll is usually between 300 and 200, 300 for small wings, 200 for larger wings. Pitch is between 200 and 100. 200 for small wings, 100 for larger wings. You can change these later, even after the Autotune. Marc Hoffman wrote about doing rolls and counting frames if you want to get these numbers a bit more precise. If you’re into heavy acrobatics with your plane you may want to follow his example.
#10 Reset your Servos to 1500
Go into outputs tab and change all the servo numbers to 1500 if they aren’t here already (By default they are 1500 on new builds). Go back and look at your servo arms, they should all be at 90 degree angles to the control rod. If not you need to fix this.
#11 Reset Control Surfaces to what you feel should work
When you plug the battery in INAV will boot up and when ready will set the control arms to 1500. Thus, plug in the flight pack (battery) and wait around 20 seconds to see if the control surfaces move. Once you’re past this point, you can reposition the control surfaces.
If this plane has flown before
The servos are now at 1500 and the control arms are at right angles to the control rods. The control surfaces have probably changed. If the plane flew well in manual before, moving the control surfaces back to where the plane flew well will get you back to flying faster. Only do this if it flies well.
If the plane hasn’t flown before, or didn’t fly well
With the servos at 1500, and the control arms at 90 degrees for each control rod, the control surfaces should be flat. The rudder shouldn’t be off to one side, ailerons should be flat on the wing. Elevator should be flat as well. If this is a flying wing, or plane with elevons; the elevons should be flat. Note: Some flying wings need a bit of deflection (reflex) sometimes 2 to 3 degrees up. Check with your manual or ask in the group about this for your particular plane if uncertain.
Overview of the process:
Now that you’re back to zero, we’re going to get your plane ready for a manual trim, perform the manual trim, do an autotrim. Do another autotrim then, when you’re ready, do an autotune. I wouldn’t proceed forward without performing and resetting your PIDs and trims. If you don’t do this, you’ll keep battling a plane that’s off in some way.
The 90/10 Rule
INAV can be summed up this way, it’s 90% how the plane inherently flies. The last 10% is what the flight controller does to improve the flight. In our group there is a lot of talk about the last ten percent, and not enough talk on the first 90%. People will want to know what magical PIFFs we can offer them to fix a plane that doesn’t fly well. I cannot emphasize enough how important a well setup plane is for INAV to fly well.
#1. Sometimes plane designs are suspect
Most planes on the market will fly well. Some fly fantastic, others barely fly. If this is your first INAV plane, let’s stick to the planes that fly well/fantastic. There are many great videos by Andrew Newton that cover nearly every plane and you can check our group’s Facebook Page and do searches for your plane to see if others had issues with it or what people have said about it.
#2. You may want to use a “Plug & Play” plane for your first build
These planes have motors and servos already installed along with the ESC. It’s rare that these planes have top shelf parts but at least you have something that will most likely fly.
#3 Have modest expectations–
We’ve had many people want their first INAV plane to be something large or elaborate. You need something smaller and more simple for your first build. It very likely may crash. We usually suggest the AR Wing/RMRC Recruit because they are cheap, forgiving, and you will never outgrow it. It’s a manageable size, and the smaller size planes to be fairly squirrely when you dip below 700mm.
The Build Process
A word about your electronics
- The GPS, RX and VTX shouldn’t be near each other.
- The VTX can cause problems for your GPS if it’s very close.
- The VTX can pick up noise from the ESC which will show up in your video feed.
- If you’re using a BLHeli speed controller, you should also use a 470MF 35V or higher capacitor near where the power leads meet the ESC.
- The VTX needs to be away from the ESC including the power lines for each not overlapping each other and keep it away from the motor.
- The GPS tends to like being by itself. If it’s taking a long time to lock in satellites, move it further from electronics. It should clear up the problem right away.
- There are many videos that explain how to install your RX antenna for maximum efficiency. It’s too large of a topic to cover here.
The more you can keep things off the aerofoil usually the better the plane will fly. People often bury VTXs, RXs and GPSs in their wings to help smooth out airflow issues.
Avoid the extras
Yes it would be exciting to add your GoPro to your plane for your maiden. A lot of people have broken their HD cameras trying to do this. Just focus on getting your plane flying first. If you need the weight of a GoPro to balance the CG, use dummy weights instead.
Center of Gravity
Why CG is important? Your plane needs to be balanced when it flies. This is true of all planes. A plane that is “tail heavy” flies with the nose pointed up (if it does fly at all). If it does fly it will be sloppy, all over the sky and hard to keep flying in one direction.
A plane that is slightly nose heavy may fly fairly well. But it will require some extra elevator to get it airborne. It may also require more speed to keep it moving and prone to stalls. If it’s too nose heavy it will crash on take-off Your flights may be substantially shorter. If you find the sweet spot on CG, flying the plane should be a nice experience.
Often times the CG isn’t exactly where they tell you in the manual. You can start with the suggested spot but experiment for yourself to see if it can be improved for your situation. You often do this by moving the CG backwards toward the tail. It means less weight is needed on the nose. You can use pins to mark where you have the CG and add more pins as you change it.
Side to side balance
Holding the motor in one hand and the front or back of the plane in the other hand figure out which way the plane falls. You’ll want to use a counterweight to ensure the plane maintains stability. You can use lighter weights closer to the wing tips to counteract the forces without adding significantly more weight to the plane. You will notice the plane will make smoother turns once you do this.
We are going to assume your plane has been well setup and is ready to fly. Issues like binding control arms, loose servo horns or servo slop create problems that are hard to identify in INAV. It’s up to you to get the plane in good mechanical flying condition.
We talked about static weight balance, but dynamic balance induced by drag is also important. Do not add antennas or cameras or other equipment on one wing only or it will induce a yaw momentum the bigger the further the object is away from the cg. A vertical wire has a considerable effect, especially on flying wings as there are often no vertical stabilisers. The resulting “dirty air” may induce or worsen the infamous “wing wobble”.
copied from Purrz75 user’s manual, www.flypurrz.de
Step #1. Getting a good manual tune
This is where you fly the plane with a manual tune. It’s the only time you will need to use your radio trim. If you have experience flying planes in the past, especially LOS, you will be at an advantage at this stage.
- Put the plane in manual
- Take a moment to pray
- Launch your plane somewhere soft such as grass or bushes, it may not fly
- From here to completing an Autotune, stick to one flight pack type
- Turn off all mixing, radio trims, expo, and dual rates in your radio!!!! It doesn’t mater if your plane has elevons. You should have configured the wing in INAV mixer. The radio needs to be pure without any modifications.
Your first manual flight.
If you’re uncertain, and you’re doing this by yourself, record yourself launching the plane. This video by Flite Test does a good job showing how to do hand launches.
This video by Andrew Newton should be required viewing by everybody flying a Bixler style (Mid-Fuselage Pusher) plane. Deny the dip!
If the plane does a fast crash close to where you launched, it can be one of many problems.
How to evaluate a manual flight
- Bad technique
- Nose heavy plane,
- Reversed control surfaces
- Too little thrust. Too much throttle resulting in prop stall and loss of thrust, especially on high pitch props
- You can keep working through it until this is figured out. If you can’t get help at this stage, share a video of your launch with the group and people will help you sort this out
- If the plane flies a bit and then lands you may need more thrust. Give it more throttle and try again
- If your plane shoots up, turns then crashes it maybe that it’s tail heavy or you’ve given it too much throttle and it stalled
- From this point, we’re assuming you can get your plane to fly
Planes that are nose Heavy
Work on pitch first
The reason you want to work on pitch first is because if you have issues with CG this is where you address them. A plane that pulls left or right isn’t as big of a deal to iron out. The relationship between CG and the elevators (elevons) is where too many problems occur. Getting this right is often the difference between a plane that flies well and one that doesn’t.
Holding a lot of back-stick
When you hold back-stick (right stick, down) it’s because the plane would crash into the ground. You have a few choices at this point.
#1 Move CG Backward
What this means is the nose is heavy and moving CG backward actually means moving the weight such as the flight-pack (battery) toward the back of the plane. This often fixes the issue.
#2. Use a lighter battery
Sometimes batteries have a predefined space they can fit into. If your battery is too heavy, try a lighter flight-pack.
#3. Move your elevator/elevons up
This will work too. Sometimes you want to have a plane that is nose heavy because it will penetrate the air better on windy days. Or, you’re setting up a plane that is built for speed. What you may be losing out on is the plane’s ability to glide, it will need more speed to avoid stalling, tip stalls may be really bad, and the plane may get damaged when landing because it comes in hot. It’s a matter of degrees, a bit of up trim may not affect the plane that much and can improve a flight, a lot of up trim may be a sign that the CG is off and should be addressed in other ways.
Planes that are tail heavy
A tail heavy plane is one where the nose sticks up because the tail weighs more than it should. It’s great for gaining altitude but is difficult to fly straight. It’s inefficient because the plane’s orientation makes it less aerodynamic. A tail-heavy plane is sometimes hard to figure out at first. Here are some signs of a tail heavy plane
- The plane goes nearly straight up, rolls to one side and crashes: What happened is the plane stalled on take-off
- When flying in manual you are constantly steering the plane to keep a straight heading
- A gust of wind knocks the plane way off of it’s heading: You’ll know when this happens
- Point the nose down test: This is a sure-fire way to test for a tail-heavy plane. Get the plane up to a fairly high altitude and while flying level (with enough power) point the nose down at 45 degrees. Let go of the stick. If it balloons back up and perhaps even stalls, you have a tail heavy plane.
What you can do about a tail heavy plane.
Move the CG Forward
This means moving the battery (flight pack) forward toward the nose of the plane, if possible.
Battery weight, orientation-
If you can make it fit, you can try a heavier battery. If you have a battery that is stubby (short, fat rectangle) try it out. It will put more weight closer to the nose. On planes like the AR Wing, the battery runs perpendicular to the length of the fuselage. If you can, try and orient your battery perpendicular to the fuselage, closer to the nose.
This isn’t always my favorite option because I would rather have extra weight going to a battery which can make my flights last longer than just adding weight. If you are going to add weight, get it as close to the nose as possible. This means you’ll use less weight overall to accomplish your CG balancing. You can use fishing weight, lead shot, or junk you find on the side of the road. I sometimes will use old AA batteries as dead weight.
Adjusting for roll and yaw
If you’re newer to flying it best you use radio trim to get your plane to stop rolling one direction or another. If you’re flying a traditional plane and the plane isn’t rolling but is heading off course this can often be fixed with a yaw adjustment (the rudder). When playing with yaw, a little goes a long way. If you’re adjusting more than a few clicks of radio trim for yaw, something else is wrong. Often times it’s a symptom of a tail heavy plane.
Flying wings are harder to work out roll and yaw issues. Issues like heavy electronics on the wing, things on top of the wing interfering with airflow (such as antennas) can make one wing slightly less efficient than the other. One wing will dip, the aileron or elevon on the wing that is dipping may need to be raised slightly to compensate. You can slightly lower the aileron or elevon that isn’t dipping. If you’re moving control surfaces up or down more than a few degrees, you have larger issues such as CG or things on your wings altering airflow.
The nuance of flying manual
It’s hard to explain exactly what a properly setup manual trimmed plane should fly like. The only thing I can tell you that would exactly get the point across would be for you to try out an RC flight simulator like AeroFly or RealFlight. They have examples of real RC planes and I have to say having flown a simulator and then the real plane, they’ve really nailed it. You even use your transmitter to fly the planes. These planes are properly setup and fly accordingly. There are some real advantages to learning how to fly Line of Sight with RC planes. A simulator will teach you how to do this. There is a game called Wings Sim, but this is more of a game than a simulator. A free alternative is PicaSim.
When you figure out how to fly manual, a properly setup RC plane doesn’t need a lot of user input to keep it flying. The better job you do refining manual flight, the better INAV will fly for you.
Before you move on
The manual tune is the one spot I find that will make or break a plane’s success with INAV. There is a difference between a plane that flies with a manual tune and one that flies well. The notion that the plane somewhat flies okay with a manual tune and INAV will smooth it out is a recipe for disaster. Listen, you’ve put so much work up to this point just getting the plane to the flight line. Why cut corners here?
A well tuned manual plane is one that holds it’s heading and you can let go of the sticks without the plane falling out of the sky. If you’re afraid to let go of the sticks, or to take your eye off the plane, it’s not ready.
#Step 2 Moving into modes
We’re going to take your plane up to 100 meters because we’re going to go into flight modes. Follow this order. 100 meters, or three mistakes high, is the altitude where you can make, realize and fully recover from three control mistakes, either done by you or by the fc. It’s an old line of sight flying rule and it endured so long because it works.
Take your plane up in manual to a fairly high altitude. Again, your plane shouldn’t be showing any serious flight issues as you gain altitude.
You can freely switch into Acro mode. This mode is most like manual with a little bit of stabilization. You should have no reservations about going into this mode, it doesn’t work like other flight modes thus, even if your board isn’t calibrated well enough you should still be fine in this mode. Drop down about 20 or 30 meters and see if you can get back up to the altitude you were before. If you’re struggling in this mode to get back up, but it was no problem in manual, you need to go back into configurator .
In Configurator PID Tuning Tab- Right side on the first screen you see Feed Forwards. Add 10 or 20 to the number (Default is 50) and save. This will give you more pitch control surface travel. Don’t do this just in case.. Too much of this pitch FF can really have unwanted consequences.
Once again, take your plane up to over 100 meters, put it in Acro mode, this time it should be flying fine. You should be able to gain and lose altitude and have good control of the plane.
Check out your artificial horizon
Roll left and right. Artificial Horizon isn’t the best feature in INAV and it can drift. Anyway, you want to make sure that level for your plane is what is showing (eventually) in Horizon. If not, go back and update the calibration as described earlier.
If you speak German, Marc Hoffmann covers this topic in this video.
Drop into Angle or Horizon modes
The plane should fly okay, perhaps it’s slightly rolling one way or the other but it should be flyable. But, just in case the flight goes to hell, get ready to drop back into Acro or Manual flight modes.
If you’re flying in either Angle or Horizon without issue you’re ready for an Auto Trim. If you didn’t set the Max Pitch and Max Roll as described earlier Angle Mode will be very difficult to turn the plane around, and it will be difficult to regain altitude. You will need to go back and change the numbers in the PID Tuning section described earlier.
Step #3 How to Perform an Autotrim
- You need to be in Angle Mode to do the autotrim
- You want a calm day without a lot of breeze. Sometimes you have to time it between gusts if you’re not so lucky
- Get the plane flying as level as you can, let go of the sticks and turn on auto trim
- If the plane starts to roll one direction or another or drop altitude those five seconds seem like eternity. Just let it do it
- Fly the plane around after five seconds in either Angle or Horizon mode. You aren’t looking for perfection, just better than you had before Land the plane, disarm, turn off autotrim
- Take off and repeat the process. This time you should be a bit more picky about how it performs. You can cancel the autotrim and restart it again to see if you can improve the flight performance
- If you can’t quite get it, and the plane seems to always roll a bit left or right, do as best as you can, land, disarm,turn off autotrim
- You should be able to get it with two autotrims. A third one means that it should be clearly what you’re after. If, after 3 servo autotrims you’re still not getting, check your horizon in your OSD to make sure it’s not slanted. If it’s not, you may need to ask for help. The best thing to do is record a short flight video from your goggles and share it with the group
- If you’re flying around in horizon mode and the plane is dropping in altitude when taking your hands off the sticks go back to board orientation and watch Darren Lines video, he mentions adding to pitch at the end of the video. You need to add more pitch in the configuration tab
- You are done (for now)
- More info found in the Masterclass Tuning Guide Phase 1
Evaluating your Autotrim
By this point you really should have a plane that isn’t wandering around in the sky. It should be very flyable in Horizon mode and Angle Mode. Congrats, you need to go back to your computer.
Go into outputs tab in INAV Configurator Each control surface should be between 1450 to 1550. Don’t be surprised if it’s not. Here are some refresher diagrams
If your Elevator is below 1450
This means INAV is has increased the nose up pitch. You’ll want to turn on your radio, plug in a flight pack let the plane recognize your radio. Where the control surface is at, stick a pin in it, lock it in place. Unplug the flight pack and turn off your radio Reset servo to 1500 in iNav, manually adjust the control surface so that it stays at the original position at 1500.. Repeat with other control surfaces if needed.
If your Elevator is above 1550
If it’s an elevator it means you have too much elevator up and INAV is toning it down. Repeat the process above
Ailerons or Elevons not between 1450 and 1550
- The control surfaces move independent of each other
- If the value is under 1500 the control surface is being moved upwards
- If the value is over 1500 the control surface is being moved downwards
- Repeat process as described in the elevator sections
Rudders not between 1450 and 1550
- Under 1500 for rudder for rudder means the rudder moves to the left.
- Over 1500 means the rudder is moving to the right.
- Repeat process as described in the elevator sections
Back to the field
- Try the plane out in manual to make sure it’s still flyable.
- Take it up to the desired altitude and repeat the autotrim process a couple of times. By now it should be flying very smoothly in Horizon and Angle modes.
- Test out Return to Home, it should be smooth as well. The 3D Cruise mode should work well.
What is crucial is that the control surfaces are between 1450 and 1550. If they are, you’re golden. You’ve got a plane fly flies well in flight modes and manual. It’s time to move on to the Autotune. If the plane has major flying issues after all of this, consult with the group. Autotune works best on a plane that flies well at this point.
Step #4 Perform an Autotune
So, you’ve struggled up to this point. You’ve gone back again and again and adjusted control surfaces, check servo settings and made sure that the plane is flying well. The Autotune is going be anticlimactic. Oh, it’s going to do something, but the thing is, it’s not going to adjust your plane all that much. Not like before when you skipped Autotrim all together. This is the icing on the cake.
Performing the Autotune
- Again you need a mostly calm day with little to no wind.
- Take your plane up to a comfortable altitude.
- Make sure you’re in Acro Mode.
- Get your plane flying at medium to high speeds.
- Turn on Autotune and start making the plane do rolls and loops.
- You want to fly aggressively if you can.
- Some larger planes, or planes you don’t want to invert you can simply highly roll side to side.
- The first 30 seconds the plane flies fairly poorly so you want to be well above trees when you do this, otherwise it will get stuck in tree. Don’t ask me how I know.
- Try to have around at least a five to 10 minute flight if possible,
- Fly the plane like you normally will,gain and lose altitude, do tight turns, have fun.
- When it’s time to land, turn off Autotune before you land.
- Land and disarm the airplane
- Hold the left stick down in the bottom left corner, and the right stick in the bottom right corner. Hold it there for three seconds.
- You should notice the plane flies even smoother on the next flight. The stabilized modes should work great, your return to home should work great, your 3D cruise should work great. You shouldn’t gain or lose altitude in 3D Cruise.
- Go home and check your PID settings to make certain the changed after the autotune.
- Save these settings by writing down these pid numbers or by capturing a screen shot.
- Go to CLI, backup your plane with a Diff or Dump command .
- If you like how it flies you can always go back to this
- More info can be found at the Masterclass Tuning Guide, Phase 1 .
How often do you have to do an Autotune?
You don’t really ever have to do it again. If you like the PIDS, keep them. If you break a servo and you need to start over again with manual trim and autotrim you can keep the PIDS the same from your Autotune. You will not need to repeat the process. At some point after you’ve adjusted a few INAV planes you may want to go back and see if you can wax an even nicer autotrim and run autotune once again. Maybe you can get the plane to fly even better? If you’ve changed a motor you may want to run the autotune again.
How often should you do an autotrim?
People will often perform an Autotrim at the start of a new day of flying. After a successful autotune it’s nice if you can keep the trim between 1450 and 1550, but not required. You should do this if you change to a heavier or lighter battery pack.
Still have issues?
The good news is that more can be done. It’s just that we’ve reached the end of this document. INAV tends to work best on planes 1500mm and under. It will work on the larger gliders but there are other factors to take into account. Which opens the door to future documents on the subject.
Want to keep going?
I wrote this document after about two years of trial and error getting INAV to fly the way I want it to. Instead of buying new planes I decided to put INAV on older planes that I rarely fly. I figured if they die or don’t come back it’s not a big loss. The problem was that not only did they not fly well as a Line-Of-Sight plane, they didn’t fly all that much better with INAV. Not like I hoped. It wasn’t until really started studying the Masterclass tuning documents that I started to figure out what the issues were.
After setting up many planes with INAV what I discovered was that very common problems kept popping up. This document is the culmination of all the problems I’ve encountered and had to learn along the way. These problems are associated with, but outside the scope of the INAV Autotrim/ Autotune process.
Not only did my old “Crap build” planes start flying remarkably better, I even went back and fixed my LOS planes that don’t use INAV and got outstanding results. The problem though was that seeing people’s flight videos and noticing issues that I’ve encountered along the way, it’s hard to isolate it down to one specific issue. Things build on each other. If your build is off you may get CG issues. Thus when your CG is off the plane won’t fly as well as it could. If the manual trim is non-existent and you’re relying on autotim and autotune the plane’s issues will be impossible to fix by changing settings in INAV.
This is a process, keep at it and you’ll get better at it. You will have planes that you enjoy flying.