INAV Wind Estimator

INAV 2.0: Wind estimator. What does it do? Tries to estimate the speed of the wind (obviously) as well as wind direction. Let's be honest, it's experimental and relays only on the difference of predicted and actual flight path. So do not even try to think it will give accurate measures. But my tries says that wind estimator results are plausible as long as an airplane is stable in the air.

Just flying: INAV 2.0 on a 7 inch long range cruiser

One of the first videos recorder with my 7-inch endurance quadcopter based on iFlight XL7 v2 frame. Since that evening I have changed a few things and now this 7" drone flies better. But's let's keep a track how it was back then:

How to solder 18650 Li-Ion batteries - video tutorial

All 18650 Li-Ion batteries are hard to solder. Well, not only 18650 but all nickel plated metal elements can be very hard to solder. But only if you do not have the proper tools. In this case, proper flux: soldering acid. Forget about sanding, scratching and other voodoo. There is a better way!

Getting started with 18650 Li-Ion batteries

18650 Lithium-Ion batteries are the workhorse of modern consumer (and not only consumer) technology. If you have anything that is battery operated and there is a "Li-Ion" mark anywhere on it, probably it is powered by 18650 Li-Ion battery. Laptop batteries, cordless drills, cordless tools, e-cigarettes. All of them (probably) have 18650 cells inside.

In this video, I will just go with the basics of 18650 cells. Dimensions, protected / not protected difference, weight and so on. Expect more in the future!

My Reptile S800 Sky Shadow flying wing

I am fully aware that Reptile S800 Sky Shadow EPP flying wing is not a fresh topic. It is on the market for much more than a year and the internet is full of reviews. So it will not be a review. I will only say that I like S800 very much. Much much, much better than ZOHD Nano Talon ;)

Specs:

• Flight controller: Matek F405 Wing, the best INAV compatible flight controller for fixed-wing airplanes. Period
• Motor: T-Motor F80 1900KV - it' an oversized mini quad motor. With 2408 it's slightly too big for drone racers but provides a shitload of trust and torque for small airplanes. Oh yeah, it's rated for 1000W ;)
• Propeller: APC 6x4 clone. Combined with the T-Motor F80 1900KV it's enough for 120km/h flight. Too bad one has to cut foam on S800 to fit 7-inch props
• ESC: Racestar 35A Tattoo - just works
• Video transmitter: TBS Unify Pro HV
• FPV camera: RunCam PZ0420M
• Radio system: FrSky R9 Slim receiver with EU LBT firmware and FrSky R9M TX module. With the latest firmware, this thing finally works, but it's kind of far from perfect...
• Power is provided by 4S mini quad LiPo battery. I had to replace the main compartment cover with 3D printed one and cut some foam to fit it. I like to keep my batteries unified so I can swap them between airplanes and drones

iFlight XL7 v2 7-inch endurance quadcopter

7-inch drones are "special". They are not as smooth as 5 inchers but they shine in terms of range. Cruising speed of 50km/h, 8 minutes of flight and it easily can fly a distance of 5 kilometers before the battery runs dry. I never really flew it that far, but it should be doable with the equipment I have over there.

What I'm showing over here is based on iFlight XL7 v2 carbon drone frame with some "special" motors. But everything else is almost like in a normal racing FPV drone.

• Frame: iFlight XL7 v2
• Flight controller: Matek F722-STD
• Motors: TBS Endurance 1450KV
• ESC: DYS XSD30A
• Propellers: HQProp 7x3.5x3 V1S
• FPV Camera: RunCam Eagle 2 Pro
• FPV transmitter: Matek 5.8GHz HV
• GPS: Beitian BN-880
• Receiver: FrSky R9 Slim+
• TX module: FrSky R9M
• Firmware: INAV 2.0 RC4

How to use INAV Autotune

Autotune (or Auto Tune) that is present in INAV for quite a long time is a working solution for tuning PID (or rather PIFF) controller used by INAV on fixed wings (all airplanes, flying wings). Not like all the attempts designed for multirotors, this one actually works.

INAV Autotune can be used on any airplane and is fairly simple to use as long as you follow a few simple steps:

Two things that you HAVE TO change in Betaflight (3.4 and 3.5)

After weekend tests of Betaflight 3.5 and some discussions with Betaflight developers, here are two things you have to (yes, have to) change in Betaflight 3.4 and 3.5 if you did not did that yet. Worth to do it!

What is Betaflight 3.5 Feedforward and how to use it

Betaflight 3.5 is just around a corner and it brings new cool things. There is no more Dterm setpoint weight and Dterm setpoint transition (relaxation ratio). They all were replaced by easier to understand Derivative and Feedforward (Feed Forward when you refer to the control theory tho).

Betaflight Derivative and Feedforward parameters are the new way of controlling "damping force" of the Dterm and responsiveness of a drone. The more Derivative gain you set, the more "damped", "delicate" and "swooshy" drone will be. The more Feedforward gain you apply, the more responsible to the sticks it will be. It's almost the same as with Dterm setpoint weight, but in my opinion, made simpler and can be set separately for each axis.

Soldering, rosin, flux and a Stannol x32-10i flux pen

If you really really want, you can solder without flux. But it is a painful experience. Almost all modern solders have flux integrated into its core. And as long as you do not try to solder anything big, it's enough. Of course, sometimes it is not enough and you have to help yourself with additional flux.

My favorite solution lately is a flux pen. Like Stannol x32-10i