Taranis: The Kapow Trigger!
Here's an interesting thread for competition R/C sailplane pilots on the "Kapow" spot landing technique developed by Bob McGowan, who gives a detailed description of it in this post. The technique was dubbed "Kapow" by Daryl Perkins, who has posted a series of videos on YouTube of Kapow in action:
Basically you get low and slow, and then, through a custom radio mix, you simultaneously apply maximum reflex plus down elevator at just the right time to nail the landing target.
I confess that I haven't tried this myself yet, but do I intend to at the first opportunity. Meanwhile, I've come up with what I think might prove to be an easier and more efficient way to accomplish a Kapow landing...
That is, if you use an FrSky Taranis radio.
I don't have much use for potentiometers, especially since, with Mike Shellim's help, I've worked out ways to "overload" my trims so that I can do all sorts of different adjustments with them. I'll write about that in another blog post, but for now I'll just say that I've eliminated any normal application for sliders LS and RS. (And I've already disposed of S1 and S2 by replacing them with switches.)
But recently, while holding my Taranis and wondering "Is there anything I can use these sliders for?" I realized that one of those sliders could function sort of like a gun trigger. You can push the slider forward, enable a function using another switch, and then hook your index finger around the slider and pull it back to trigger the function.
I chose the left slider, LS. When it's pushed forward I call that position LS↑, and when it's pulled back it's LS↓.
The Kapow Trigger setup is completely independent of any existing model memory setup in your Taranis. Whether you're using a Mike Shellim setup or something else, all you need are eleven open Logical Switch slots, six of which comprise a safety arming system to help prevent unintended triggering of Kapow, plus seven Special Function slots, plus a couple more Special Function slots if you want to add sounds.
The Kapow Trigger works like this:
To arm it, push the left slider forward (LS↑), move SG down (SG↓), and then move SG up (SG↑). (Keep in mind that in Taranis talk, when you're referring to SE, SF, SG, and SH, which are the switches on top, down is up and up is down.)
To disarm Kapow without triggering it, pull SG back to SG- or SG↓.
With Kapow armed, when you pull the trigger your plane's ailerons and flaps will immediately go into reflex and your elevator will go down, but this will only last a short time. My impression from the Daryl Perkins videos is that a time as short as one second ought to be enough, but the duration is adjustable. (I figure a short time might be wise just in case you somehow manage to trigger it accidentally. You're more likely to have a chance to recover.)
When Kapow times out, full radio control will be restored except for your flaps. Instead, they'll go to their neutral positions and stay there until you move the flap stick to the top position. If your flap stick is already at the top position then you'll have to move it down, at least a little bit, and then back up, before regular flap control is restored. This feature is meant to keep your flaps off the grass.
So here's Kapow Trigger, Version 1.0, on your screen and also as a downloadable PDF file. Please leave your comments, including any problems or suggestions for improvements.
And by the way, this WAV file, from this post by Imageek2, sounds pretty cool and plays properly in a Taranis! Store it in the SOUNDS/en/ folder on your SD card and use a Special Function to make it play with Logical Switch L30.