You’ve done it again. It was shaping up to be a great race, but you clipped a gate and landed on your top. Up until now, that’s where the story ends—in a DNF—but with Betaflight 3.2, you may get another chance to post that time on the board.
If the reference isn’t immediately obvious, turtles and tortoises have a difficult time flipping over if they get stuck on their back. Your racing drone, much like the turtle, will probably need to wait around for some help if it ends up upside-down. Crash and end up on your top? You got turtled. That’s a race-ending condition. Racing props do work in reverse, just not very well—but there’s enough thrust to pop up and flip over. Anti-turtle is a temporary flight mode that enables this.
First, make sure you’re on Betaflight 3.2+ and you’ve updated your ESCs to at least BLHeli 16.67. We covered this in our Betaflight 3.2 Guide.
You’ll need to assign a switch for this feature. Features like these are where all those extra switches on that expensive radio come into their own. Find an unused switch and AUX channel and make your way to the Modes tab of Betaflight Configurator. Look for “Flip over after crash” near the bottom of the list and assign it to this channel. I’ve chosen AUX 6 on my Taranis for this example.
If you have this mode enabled, you can’t take off normally. It’s a good idea to have your radio help you to not forget. This is a good candidate for a power-on switch warning, which is done in the Model Setup tab in OpenTX. Another kind of persistent notification or alarm would be great as well. I set up a Special Function (SF11) that looks for the Anti-Turtle enable switch (D-up) and activates the Taranis X9D+’s vibration (haptic) feedback every few seconds. Now is a good time to set these up. You’ll be pretty sad if you miss a race start because you forgot to check.
When it comes time to use it, it’s pretty simple. You can’t change your motor direction when armed, so disarm your craft if you haven’t already. That will bring everything to a stop. Flip your anti-turtle switch, then re-arm. Even if you have airmode permanently on and “motor stop” disabled, your props won’t start spinning. Anti-turtle overrides and works differently than every other flight mode. Once armed in anti-turtle, throttle will do nothing, but pitch and roll will each activate two motors. Point your stick in the direction you want to flip. If your props are free to rotate, you’ll pop right over!
Now it’s time to disarm again and disable the anti-turtle. Re-arm, and off you go as if nothing ever happened.
Use with Care
Anti-turtle is great in theory, but it’s not always so simple in practice. If you end up upside down, something probably went terribly wrong. Anti-turtle is only going to save you if your quad is still in good shape: your motors still work, your props aren’t broken, your battery is still in place, and so on. If you’ve done damage or had parts shift around in the crash, trying to fly again can damage things even further. If you had time to visually inspect the craft you would just flip it over manually, so you’re taking a risk when you use it.
Another problem to watch out for is motors not spinning freely. Grass can get caught in motors and need cleared before you can flip over or fly again. A stuck motor can burn out by trying to use it when it’s being held in place. Don’t push it more than a couple seconds. If your quad doesn’t feel right, stop trying!