INAV Autolaunch process explained step by step (Patreon request)

[00:00:03]Hello and welcome to the video. This is a quick video for a Patreon of mine, a Patreon called Dave, who is thinking about doing a maiden flight with one of these new models, but when I had a chat with him because he was a little bit nervous about it, I think it's probably the way to describe it. When I had a chat with him, he wasn't using auto launch. Now, he set up INAF in this particular model. And for those of you that watch my videos regularly, you'll know that I am a massive fan of auto launch. Even on oneoff prototype models that I get sent to kind of comment on here, I use auto launch because auto launch can do a far better job of rescuing a bad throw and controlling and climbing the plane safely into the sky than I can. So, I rely on INAV auto launch to keep these things in one piece. Uh, for those of you that don't know what this is, this is my very old Zoho HD dart, the original 300 uh 635 mm one. Uh, I love this thing. This is Walkale INAV lithium ion. Now, uh, but I pulled this out because I thought this would be a great way to explain it. I'm not going to go through how you set it up in great detail. There is a video and I'll put it down below. I will go through what the settings are that I use on almost every single plane. I've been using the same INAV auto launch settings since probably INAV 4 and I just have them in a file and I copy and paste them. There's only two settings that I change. One is the idle throttle, which is the throttle that the prop will spin at or the ASC will send to the motor, I guess, is probably the easiest way to say it, when you actually arm the model and raise the throttle on the radio, ready to throw it. And then there is a second value, which is what the throttle is going to increase up to as the model climbs into the sky. Now, very quickly, and I'll get into this in a bit more detail, it is a multi-step process, right? And it can appear quite confusing, but the way that I do it, I permanently enable auto launch in the settings in the options at the bottom. I also turn on continuously trim servos, so everything is trimmed for manual.

[00:02:14]When I come out of it, I make sure that my basic mode for the plane flying is horizon. That's going to give me auto level. So when the auto launch sequence is finished or cancelled, the plane will just immediately level out and fly straight and level. And then if I want to, I can then flick it into something else. That's the way that I like to do it here. And the only other thing to potentially think about is what the angle is that it's going to climb into the sky for. Now, the process super quickly, and we'll go through this in a lot more detail in some slides in a moment, is you're going to put the model into horizon mode and arm it as normal.

[00:02:52]It's going to start beeping. You're going to raise the throttle to 100% on the radio. The model is then ready to throw and the beeping will intensify.

[00:03:01]You get the model ready. You chuck it.

[00:03:04]The model will spin up the throttle to the launch throttle value. Set the nose up to the pitch degree that you've set and then climb for a specific period of time and it will either come out of that if it reaches the altitude that you've set. If it times out to 10 seconds is I think the normal timeout or you can cancel it any time by just waggling the sticks on the radio. Once it's finished, then it'll just fall back into what the mode has been set. While it's actually doing the launch, you'll probably spot on your radio if you're using telemetry that it's actually using angle mode underneath auto launch to actually do the launching stuff. So, let me go through this in quite some detail for Dave's benefit. Uh, but for those of you that are not using auto launch, I would strongly recommend try it out. It is a gamecher in terms of launching. I know that term gets thrown around and it's in every thumbnail. Uh, but you know what?

[00:04:00]It genuinely is. It's one of the three things that I use I now for all the time. The others are the on-creen display and also the ability to return to home reliably if something goes wrong. So before I get into the slides, it's probably worthwhile very quickly going through where all this stuff is set up inside configurator. Here is that particular model plugged in. It's still on INAV 712 in that particular instance, but as I already mentioned, the settings that I use are identical. So the only things that you really need to worry about I would suggest is setting your idle throttle and setting your launch throttle. Both of which are highlighted in yellow there. And then everything else, if you just go to the right hand side, there's a little question mark where actually explains what everything does. But if you copy my setup for all the other settings, it's going to work really well. The only other two things to maybe think about is the climb angle at 26% for a little plane like this is fine. Uh things like the launch timeout is going to be set to 10 seconds.

[00:04:58]Maximum altitude is feet in this, but it might be meters in your setup. And that's the altitude at which auto launch will have considered to be set. But these are the default settings that I use all the time where they actually play a part. Let's cover that in the slides.

[00:05:18]So let's talk about the individual steps that form part of the auto launch process. And there is only six going from selecting the flight mode on the radio before you arm right the way up to the launch being complete and then basically you flying the plane as normal. Now each of these is in a sequence because that's the sequence that the process follows. You trying to do things out of sequence will cause weird and wacky stuff to happen. So let's add all the different pieces that explain this and I'll take you through it. Now, this looks really complicated, but it's not. We're going to start here over at select flight mode. So, this is the mode that you select on the radio.

[00:06:03]Typically, I would select Horizon as the flight mode. And that is going to be the mode that once auto launch is complete or it's cancelled, that is the mode that INav will fall back into. Now, some people like to use uh GPS return to home. So, as soon as it's out of the launch process, it'll initiate the return to home. I will talk about that in the next slide. I would recommend when you're first trying it out. Just set it up so that it's horizon. Why horizon? Well, that is a self-level mode. So if you are not quite ready when auto launch finishes, the plane will just settle into a neutral level position and continue to fly straight and level rather than if it's in something like manual or acro when you're not quite ready to catch it, it can turn over and fly straight back into the ground. Once you have selected the flight mode, and again I would recommend going for horizon, the next step then is to arm the model as you would normally.

[00:07:04]Now, because you have selected permanently enable auto launch, which again is the way that I would recommend that you do it. However, auto launch can be selected as a flight mode. Once we arm, the model is then in auto launch and you'll know it's in auto launch because it'll start to beep and it'll continue to beep. And that's a warning to let you know that it's in auto launch and it is ready to start the process.

[00:07:32]Now, the motor won't start yet.

[00:07:35]It's just sat there waiting to go and complete the next stage. So, if you shake it at this point, it isn't going to do anything. You're going to see auto launch is going to be in your onscreen display. And you might see angle as the mode on things like the telemetry. And that's because angle is actually what at the moment auto launch uses to actually launch itself into the air. So you're there, it's armed, it's beeping. What do you do next? Well, this is the slightly weird thing is that the next thing you do then is raise the throttle. I just put the throttle to 100%. Make sure you have a firm hold of the model. The fact it's beeping will let you know that it is in auto launch already. Once you raise the throttle to 100% then the motor will start to run at whatever you have set in the settings for nav FW launch idle throttle by default that's zero. So as you raise the throttle to 100% on the radio nothing will happen. And again this catches a lot of people out because they complain that oh my my motor isn't running. Well that's because the beeping is going on.

[00:08:51]You're in auto launch mode. However, you will notice that the chirps will change.

[00:08:57]The beeping will change to a different mode to let you know that now it is ready to detect the throw and you need to be super careful about this. Once you've raised that throttle, you need to be ready to chuck it into the air.

[00:09:12]I like to have nav FW launch idle throttle at a value that's going to spin the prop. Lots [snorts] of people don't like that. I personally like it for two reasons. One, it confirms to me that I am in INAV mode, launch mode, for those models where it doesn't have a beeper, but also for those models that need to get into thrust very quickly. As soon as I throw it, it takes a lot less time to spin up the prop from the idle to the actual launch throttle.

[00:09:46]So, once you have raised the throttle, the beeps are going to change. The motor may start spinning if you set the idle throttle above the zero. And then you are going to throw it into the air.

[00:09:57]You're not going to throw the thing too high so it just stalls and crashes back into the ground. You're going to throw it reasonably level slightly up into the air. As soon as the model detects that it has been thrown, then the motor will speed up to the NAV FW launch throttle value. And that's typically going to be 95 or 100% throttle. There are some models like the TBS JPTO on things like a 6S setup where you only need to set the launch throttle to 70% on 6S, but something like 95% is going to be great on a 4S setup. So, it needs to be set for the model that you would normally launch at. Most of us would tend to go, unless it's a very, very aggressive, fast model, in something like 80 to 95% throttle. As it increases that, it's also going to pull the nose of the model up a little bit at the nav FW launch climb angle that you have set in the settings. That's usually going to be 20 or 25°. And it's just going to keep the wings level, keep the nose up at that angle and increase the power to the motor to that launch throttle and just stay there. And that is where the model is going to climb into the sky. You don't have to touch anything. You can just watch it gracefully head for the clouds.

[00:11:25]Now, there are a number of ways that the process is going to finish. You can cancel auto launch by moving the controls on the radio. As soon as you do that, it will immediately cancel it and that is going to then fall back into horizon mode or whichever you've got set. There are two additional settings that you normally set. The model is going to climb to the launch max altitude and when it hits that altitude, it will cancel the auto launch. I would recommend that you set that about 50 feet below what your maximum legal ceiling is. That makes sure that in auto launch you don't actually climb past your legal ceiling and do something that people are not going to be happy about.

[00:12:10]The other thing as well is if it gets to nav FW launch timeout, it'll time out as well. In reality for me, I tend to throw the plane, it starts to climb, and then while it's doing that, get comfortable with my goggles, get comfortable with my radio, and by the time I finished all that, I just move the stick slightly.

[00:12:33]That cancels auto launch, and then we're into launch complete. And that is where at that point, it will fall back into whichever mode you selected here, right before you arm the model. And that then is you flying normally. And that's the entire process. So there are a couple of steps. I'm going through it at quite a granular level here because the question that I've had about this, but actually once you've done it a couple of times, it becomes kind of second nature. There are however a couple of gotchas in each of the stages that I tend to hear about.

[00:13:06]So let's go through those. The first one is about selecting the flight mode. As I said, I would recommend that you select the flight mode as Horizon. That will allow you to arm. Some flight modes will not allow you to arm. Some of the modes like return to home. If you try and have the model into return to home before you throw it, typically it won't let you arm when that's the condition. So, if you want it to fall back in return to home, then you have to select horizon here, then arm the model, then turn it into return to home, and then raise the throttle. So just be careful about that.

[00:13:44]The next thing then is in the arming when you arm. If you have auto launch set up as permanently enabled, it will go into auto launch. If you haven't got it permanently enabled, then you have to manually select auto launch as a mode on a switch on the radio. And of course, you need to make sure that you are hearing the beeps. And some people get confused when they've set it up and then they go to fly their model, they arm it and immediately starts beeping. Most of the times I've ever had to get involved with those, it's the auto launch beeps warning you that that's what's happening. The next stage then is to raise the throttle. Now, at this point, we are in safe condition until we raise the throttle. Once the throttle is raised, it's going to detect when you throw it. So, you need to make sure that you have a good hold on the radio, raise the throttle to 100% on the radio, and then the beeper will change its beeping, and then that means that it's ready to throw. And potentially, depending on what you've got set for the idle throttle, it may or may not start the engine. You may get the prop spinning, you might not. Double check that you've set idle throttle to the right value for your model. The next job then is to once it is like that, I would within a handful of seconds, I would throw the model into the air. It will detect that it's been thrown. I would use the settings that I've shown in the introduction to this video. And then again, don't go too high or too flat to throw. Don't throw it up at 45°. There are powerful models that can climb vertically. Lots of planes and wings do not have that ability. So launch it as you would normally as though you were going to manually manage the launch yourself. INAV will just detect that that's happened and take over. Again, launch throttle needs to be set at a value that's going to be high enough to have the thrust to enable it to climb cleanly. And the climb angle needs to be set so that it will have its nose up in the air. Don't set it too low or what you might do is a launch is actually just going to fly straight and level and potentially hit the trees in the corner of the field. The next thing then is once it's been thrown of course is that the model is going to climb. We've talked about this and three ways that it's going to come to an end. Either as a timer, an altitude that's reached or by you cancelling it by moving the sticks. had issues where people complain that it's coming out of auto launch and that's typically because they turn around, pick the radio up and bump the controls and that is why I always recommend have it in something like horizon mode cuz if it accidentally comes out of auto launch, it'll just revert to flying straight and level and then not immediately turn over on its back and power into the ground. And then the last bit here, when the launch is complete, then it's going to fall back into the mode that you have set. As I mentioned, I would recommend when you're first playing with this, don't get too carried away. Use Horizon. However, if you want to do something like return to home, then select that after you have armed the model because you won't be able to arm it if return to home is selected as a mode before you try that bit in the process. So there you have it. That is in detail how auto launch actually works. If you are a fixed wing pilot and you are not using auto launch, I would strongly recommend have a go. It is genuinely something that will change your life. It means that at the field when I go at the field, I can very casually enable everything, make sure it's all ticky boo, and then I can arm the model, put the throttle to 100%, throw this thing into the air, and know that I can look away from it briefly to kind of pick my radio up, put my goggles into position, and when I look in the goggles, I'll see it climbing gracefully for the sky with absolutely zero drama.

[00:17:49]The last thing I'll say about this is auto launch is an advanced sophisticated mode built on the angle mode that it's actually using to do the climbing. So, it doesn't mean that you can just ignore all the basic setup stuff. I'll put a link down to one of my INAV for beginners series. So, if you've never set up INAV before, go through that.

[00:18:08]Make sure the plane set up beautifully.

[00:18:09]And if it is, INAV auto launch with the settings that we've gone through today will work a treat.

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